Results 1 to 91 of 91
  1. #1
    mtbr member
    Reputation:
    Join Date
    Sep 2010
    Posts
    219

    stem length: Please educate me?

    Can someone give me a synopsis of the effects and benefits of changing stem length? I see that there are MANY different options. I've gathered that a shorter stem length tends to make a more relaxed feel as a longer stem can give a more racey position. What I'm curious about though is how to tell if you have the right length stem for ones peticular body build? What would the use of a too short stem result in? Too long? Thanks in advance!

  2. #2
    mtbr member
    Reputation: erginguney's Avatar
    Join Date
    Dec 2005
    Posts
    980
    The basic principles of which I'm aware are these:


    • The longer the stem; the slower, more imprecise, and more stable the handling. The shorter the stem; the more agile, more twitchy, and quicker the handling. The reason is not too difficult to understand, if you imagine exaggerated scenarios. Think of having a 24-inch stem. In order to effect a 30-degree turn of your front wheel, you'd be sweeping the handlebar through several inches of of side-to-side motion. If your stem is only half-an-inch long, on the other hand, the arc swept by the mount point of your handlebar on that stem will be only a fraction of an inch long for that same 30-degree turn. Similarly, it's harder for a trail obstacle to deflect your wheel when your stem is longer, because the angular momentum it has to work against (your grip on the handlebar) is being applied at a larger distance from the point where the rotational force is applied (the head tube).



    • A longer stem will also imply a longer "cockpit" (seat-to-handlebar distance), which is considered to be better for racing or climbing, since it's a bit more conducive to applying a larger force on the pedals. I believe this is because it makes leaning forward a little easier and leaning forward allows you to pedal harder. The drawback of this would be that biking for long periods of time in that forward-leaning pose is fatiguing and would not be as comfortable as a more upright posture if you do extra long rides frequently. (The "more relaxed" feel you have in mind might be arising from this posture comfort, rather than in terms of "relaxed steering". The steering will, in fact, become more on-edge and nervous, with a shorter stem--comparatively speaking.) Conversely, with a shorter cockpit, you might be tempted to stand more frequently when the need arises to pedal harder.


    In terms how you should decide on the best stem length for your particular case, the best advice anyone can give you might be "try it and see". Try at least a couple of different stem lengths (or different bikes with different stem lengths). If you feel like constantly having to reach too far in order to hold onto the handlebars or if you're experiencing back pain, it's probably too long. If you're feeling too skittish on technical descents, then it might be a bit too short. And so on... The longer the test rides you can do while you experiment with stem lengths, the clearer will be the impression that you get.
    Looking for local rides? You'll find plenty on my website: Bay Area Mountain Bike Rides.

  3. #3
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    12,037
    Basically on any bike the position of your butt is determined by the location of the pedals....so your back end is fixed..

    Extending the stem just pulls your upper body forward and down...good for climbing and going fast on the flats....not so good on downhills and especially steep down hills...

    You can't really know whether a shorter stem is going to make the wheel turn faster or slower, unless you have straight bars, cause if your bars sweep back more than your stem is long the whole situation reverses....

    Lastly most stems are angled up so you actually move the bars up a bit and forward when you go to a longer stem.

    So just figure out what is going on on your bike.

  4. #4
    mtbr member
    Reputation: erginguney's Avatar
    Join Date
    Dec 2005
    Posts
    980
    Quote Originally Posted by jeffscott View Post
    You can't really know whether a shorter stem is going to make the wheel turn faster or slower, unless you have straight bars, cause if your bars sweep back more than your stem is long the whole situation reverses....
    Good point. But, given the same handlebar, the effect of a longer vs. shorter stem would still apply in the same way.
    Looking for local rides? You'll find plenty on my website: Bay Area Mountain Bike Rides.

  5. #5
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    12,037
    Quote Originally Posted by erginguney View Post
    Good point. But, given the same handlebar, the effect of a longer vs. shorter stem would still apply in the same way.
    Not quite if the bars sweep back say 100 mm and you have a 80 mm stem then your hands are 20 mm behind the pivot...

    If you increase the stem to 100mm then the hand are at the pivot so the bars are fastest...

    If you then increase the stem to 120mm then the hands move the bars slower again.....

    So it can swing both ways.

  6. #6
    mtbr member
    Reputation: erginguney's Avatar
    Join Date
    Dec 2005
    Posts
    980
    Fair enough. I guess I should have qualified my explanation by adding "for common mountain bike handlebar shapes". I wouldn't call the scenario you're describing (handlebar sweep back equivalent to or greater than stem length) "typical" exactly.
    Looking for local rides? You'll find plenty on my website: Bay Area Mountain Bike Rides.

  7. #7
    Fat-tired Roadie Moderator
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    18,452
    If longer rides don't murder your hands, wrists, arms, shoulders, neck or back, you're at least close enough with your stem length.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  8. #8
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    12,037
    Quote Originally Posted by erginguney View Post
    Fair enough. I guess I should have qualified my explanation by adding "for common mountain bike handlebar shapes". I wouldn't call the scenario you're describing (handlebar sweep back equivalent to or greater than stem length) "typical" exactly.
    The effect is more common on downhill bikes with very short stems, and more swept bars.

  9. #9
    mtbr member
    Reputation:
    Join Date
    Sep 2010
    Posts
    219
    Thanks for all the input guys. This is exactly what I was looking for. FWIW I have a XC setup and am basically looking for the best base setup. Long rides don't "murder" my hands, but I have noticed that I seem to put more pressure on the palms of my hands closer to my wrists when I ride. I always try to make it a point to keep my wrists in line w/ my arms and hands. Its noticeable, but again certainly not painful.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    17
    One thing you can try is to make a conscious effort to bend at the elbows...This will help keep the support in your torso and off your hands.

    Sent from my cm_tenderloin using Tapatalk
    Matt | Trek 6500 Disc

  11. #11
    Fat-tired Roadie Moderator
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    18,452
    Quote Originally Posted by flynbryan19 View Post
    Thanks for all the input guys. This is exactly what I was looking for. FWIW I have a XC setup and am basically looking for the best base setup. Long rides don't "murder" my hands, but I have noticed that I seem to put more pressure on the palms of my hands closer to my wrists when I ride. I always try to make it a point to keep my wrists in line w/ my arms and hands. Its noticeable, but again certainly not painful.
    Oops, I didn't see this.

    Try moving your stem up and down in the spacer stack and see if that makes a difference. WIthout seeing you on the bike, nobody can fit you over the internet. But you can end up with too much pressure from either too high or too low a handlebar position.

    The great Sheldon Brown covered fit extremely well on his page, especially when it comes to correcting discomforts.

    Bicycling and Pain

    I seem to be good enough at turning a deaf ear to my body that I often won't notice something that seems relatively small until it's heinously bad. I don't know how long your rides are, but I can almost guarantee that if they're sufficiently long, any little discomfort will get pretty bad.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  12. #12
    mtbr member
    Reputation: theMeat's Avatar
    Join Date
    Jan 2010
    Posts
    4,447
    Some good points made.
    More degree of rise on a stem of the same length will also shorten it's length from the pivot point, shorten your reach/cockpit, speed up steering, and put you more upright (less weight on hands), while raising your stem with spacers will not speed steering but will put you more upright. Also, the wider the bars are, the slower the steering, and the more the bars are wider than your shoulders, the lower your riding position will be.

    Have also noticed that when I change to a bigger taller tire in front because that seems to be what I like lately, that that'll also change saddle/hand weight, while the cockpit and reach remain the same.
    Round and round we go

  13. #13
    mtbr member
    Reputation:
    Join Date
    Sep 2010
    Posts
    219
    Quote Originally Posted by AndrwSwitch View Post
    Oops, I didn't see this.

    Try moving your stem up and down in the spacer stack and see if that makes a difference. WIthout seeing you on the bike, nobody can fit you over the internet. But you can end up with too much pressure from either too high or too low a handlebar position.

    The great Sheldon Brown covered fit extremely well on his page, especially when it comes to correcting discomforts.

    Bicycling and Pain

    I seem to be good enough at turning a deaf ear to my body that I often won't notice something that seems relatively small until it's heinously bad. I don't know how long your rides are, but I can almost guarantee that if they're sufficiently long, any little discomfort will get pretty bad.
    Thanks. I'll check out the link. I lowered my stem by shuffling the spacers and it seems to feel better, but I haven't got out for an extended run yet. As for the ride time... Its usually between 2-3hrs.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Mar 2009
    Posts
    393
    Sorry to resurrect a dead thread like this, but I got here through a google search and thought I would add a personal experience when it comes to stems.. IF YOU ARE A NEW RIDER, AND ARE LOOKING FOR STEM INFORMATION, READ THIS STORY.

    If you are just getting into mountain biking, choose your stem length carefully, because what you initially train with could train with could acclimate your body to a specific length of this, or size of that..

    I rode an incredibly durable 2004 Blast for my first MB. It was great. I rode single track black trails with guys who had been doing it for years and never, ever fell. The ONE time I did fall it was on a flat grassy ride and there was a hole that disconnected my from my bike, it was not on a single-track. The Blast was a 21, which is large for me at 6', but at 240+ lbs (10% BF) at the time it actually seemed to fit. But that year bike came with an incredibly long stem. As long as a stem as I've seen. I haven't measured it, but I would guess 120mm. The bike fit worked fine for me. I did not know anything else and I just learned to put weight forward and go. As a fitness buff, I had no trouble with rocks, roots, and terrain that was supposed to be for high level riders. Not trying to brag, but other than a ingrained wuss fear of serious down-hill adrenaline stuff I saw some guys doing, I was actually a natural at tough single track/climbing trails.


    So basically I got pretty good on my big 21' bike with a super long stem. I saw the guys who were faster than me riding smaller bikes and ripping them around. I wasn't rich, so I decided to get a 2009 19' Rockhopper pro for my second bike and minor upgrade. This bike had a significantly shorter natural top bar (top tube), and a no length stem. I felt it whipping back and forth in the p-lot when I bought it, and it felt like it handled great. It seemed "small" for a 19', but I thought I would get used to it. So first time I went out I ran into a serious rider who decided that we should ride together. I was familiar with the area, and it was pretty tough stuff so I thought I would show him around. Well besides my pedals hitting a dozen rocks which almost threw me a bunch of times, I went over the handle bars three times. One time over a ridge and down about 6 feet. I had never, not once, hit a rock/root/anything in FIVE (5) years of riding and gone over the handle bars. I was embarrassed, and I was sad. I wanted so bad to explain that there was a problem with the bike and not me, but that would not have been completely true. My body was completely and totally accustomed to weight forward riding where I simply could not go over the handle bars. I was 100% acclimatized to the long top tube/super-long stem combo. This was 4 years ago, I haven't rode hard single track the same since. I just fell into a routine of commuting and mild trail riding since that terrible experience. I haven't climbed the mini mountain I used to all the time, and that has taken away from my fun in life. I tried to re-train myself on the new bike, and let the Blast go actually taking parts off it etc..

    I put a longer Raceface stem on my RH Pro. but maybe 80 MM and it wasn't enough to make me feel like I would not go over the handlebars again. Despite my sad story, I still have AND like that bike. I have it down to about 24 lbs (I only have a back brake on it lol) and I commute and ride it for 2,000 miles a season at least. My 2009 RH Pro is not a bad bike. But the moral of this story is "Be careful what size and stem you really learn to ride on, because that could be the size and stem you body completely acclimates to that you will need forever."

    This post is not bashing short stems. They handle better etc. But it IS telling you to be careful what you ride hard on when you are getting into the sport.

  15. #15
    Fat-tired Roadie Moderator
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    18,452
    Read up a bit on front-center distance before you blame the stem.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  16. #16
    mtbr member
    Reputation:
    Join Date
    Mar 2009
    Posts
    393
    Thanks. I did. I see that 45% of your weight on the front tire, and 55% on the back is "normal." Pretty sure I got used to putting 50% on my front and not noticing any ill-effects because of the long top tube/long stem combo. I felt like I was going over the handle bars constantly when I changed bikes. I'm going to get a Carve next week and put a 100mm stem on it the dang thing and try to get back to riding single track. As for my my derailed thread about the other bike I was going to buy a few weeks back, I just got a refund. It should be noted that I am a long torso guy, so when my weight leans forward, it really leans forward. Thanks for the recommendation.

  17. #17
    Fat-tired Roadie Moderator
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    18,452
    45/55 is widely cited for road bikes. My suspicion is that there's a greater rear bias for mountain bikes. A shorter stem, other things equal, tends to move a rider back on the bike. So it does have some effect on weight distribution. For me, at least, my riding position is actually not very malleable. If I don't have the right weight distribution to begin with, changing stem size will hurt my back more than help my bike's stability. This is why I think getting the size right is so important - it's really the only opportunity to choose front-center distance on a bike.

    I'm glad you're getting a new bike soon. I bet your experiences help you get the most out of test riding and really nail your size. I won't be surprised if 100mm is the right stem length for you on that bike, but I also won't be surprised if it's not. Just try to keep an open mind.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  18. #18
    mtbr member
    Reputation: RS VR6's Avatar
    Join Date
    Mar 2007
    Posts
    3,781
    Its tough to say. If you look at some of the world cup XC riders...they have massive saddle to bar drops with long stems...and they are riding some crazy steep terrain with drop offs.

    Road bike frames are real short (with steep head tube angles) compared to a MTB. My 54cm (medium) road bike looks tiny next to my medium MTB. On a road bike...well...you're riding on the road. There are no rocks, roots, drops. So you can have that more forward weight distribution.

  19. #19
    mtbr member
    Reputation: mack_turtle's Avatar
    Join Date
    Jan 2009
    Posts
    6,495
    the riding position and bike setup of professional racers is irrelevant to most recreational riders, especially "beginners." it might also be irrelevant to a 11 month-old thread.

  20. #20
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    140
    Quote Originally Posted by mack_turtle View Post
    the riding position and bike setup of professional racers is irrelevant to most recreational riders, especially "beginners." it might also be irrelevant to a 11 month-old thread.
    who cares how old the thread is,it is good info. it will be forever in cyber space ,so what !!

  21. #21
    mtbr member
    Reputation:
    Join Date
    Jul 2013
    Posts
    423

    Re: stem length: Please educate me?

    Quote Originally Posted by mack_turtle View Post
    the riding position and bike setup of professional racers is irrelevant to most recreational riders, especially "beginners." it might also be irrelevant to a 11 month-old thread.
    Sorry I must have missed it. But what has changed in the bike frame design since 11 months ago, that makes new comments in this thread irrelevant?
    What works for me may not work for you. What's best for you depends on many factors. We are different from each other.

  22. #22
    Old Fart Swamper
    Reputation: Osco's Avatar
    Join Date
    Apr 2013
    Posts
    1,137

    Cool-blue Rhythm

    The simple set up for new riders:

    Get on your bike and ride,,,

    Look down at your front axle,

    If Its behind your bars you need a shorter stem,

    If the axle is visible in front of your bars you need a longer stem.

    Going shorter often needs a wider bar and more stem rise...

    DON'T go nutzoid,,,, Think baby steps.....

    Got a 90 mm stem go to a 75, NOT a 50, your a new rider remember !!

    The bike's geometry will change dramatically if you chop stem length by 40 to 50%

    Got a 7 degree rise, going from a 90 mm to a 75,,, try a 15 degree rise...
    The above changes dictate a bar change provided your not a small person..

    From a 90mm stem to a 70 or a 75 mm stem then 26"/660 mm handlebar
    should become a 28 or 29"/700/711 mm bar...

    Expert riders go radical,,,,,
    1st and second year barnstormers need small changes...

    Wider bars will open your lungs up a little, you will breathe better,,,

    Wider bars smack trees more often, you know, them crazy rodeo style get offs XD

  23. #23
    mtbr member
    Reputation:
    Join Date
    May 2012
    Posts
    248
    Old thread or not it is a good one to keep alive...lol..

    I have gone from a rigid with a long stem and a seat that was way higher than the bars and it never stopped me from riding almost any trail to a bike with 140mm travel fork 60mm stem and 20mm riser bar. Trends change and so do the way we look at how a bike works but at the end of the day it is about being comfortable and confident in the bike. My current set up did take a few minor changes to the one above with a swap to a 90mm stem with a little more rise and a bar with a 30mm rise. The reason for the change? Injury has forced me to change my riding position so I have had to adapt how I ride a little too... I pay very little attention to trends which change and the comment about seeing what pro riders use being pointless.. I agree and disagree too, they set up the bike which is the best for them so there is no point copying their set up but if you see what they ride and think about it, they ignore what others ride and go their own way to make it work for them. Yes make small changes to get to know what works for you but you may still find it ends up a dramatic change from standard. Find what works for you.

  24. #24
    mtbr member
    Reputation:
    Join Date
    May 2014
    Posts
    11
    I'm 6'4" so the vertical height of my 21.5" frame fit me great. Most of my height is in my legs though so I found the stock 100mm stem made me feel too stretched out reaching for the cockpit over my top tube. I picked up a 40mm stem first for REALLY cheap just to see what the other extreme would feel like. I knew pretty much right away that 40mm felt too weird. There was too much tire in front of the stem. I decided to get a 60mm stem to try next. I figured I'd get much wider bars than the stock 680mm ones and just cut them down if I found them too wide to match my stem. So far I've been loving the 60mm stem and 740mm bar combo. Riding single track, the front end is far easier to lift up to get over obstacles and my elbows are more bent in my default position. With the original stem my elbows we're very close to locked. It's improved my ride significantly.

  25. #25
    Rock n' Roller
    Reputation: snowgypsy's Avatar
    Join Date
    Jun 2011
    Posts
    269
    Going from a longish stem (100mm) to a short stem (50mm) changed my life. It was like going from my old jeep minus power steering and brakes to a new BMW race machine. It took a few rides to get used to the "twitchiness," then it was nothing but joy and effortless bunny hops. Wider bars are next on the shopping list. I will also say that it helped with pain I had in my back and shoulders on longer rides.

  26. #26
    Old Fart Swamper
    Reputation: Osco's Avatar
    Join Date
    Apr 2013
    Posts
    1,137

    Cool-blue Rhythm

    Hey New guys !

    Take a close look at your bars, most have a little 5 or 10 or 15 degree rise built in.

    You can rotate them a quarter turn or so,
    This will raise the grips just like adding a stem with more rise,,
    rotating the bars also to a small degree has the effect
    of going to a slightly shorter stem in relation to your body pos.

    If your riding around with your elbows locked your gonna crash..
    That front end needs to move, needs a light touch/hold and a firm grip,,
    flexible arms are the best steering damper you can have.......

    Also remember, a shorter stem of the same 'rise' will
    lower your upper body/ lower your grips,
    and put more weight on your wrists,,,just sayin,,,

    Bike Fit is EVERYTHIG, 1/4" changes in seat height. bar pos, width,
    brake lever angles, distance, from grips(Inboard/outboard)
    can transform your ride..

    Above all else you want your center of gravity low and over/through
    your pedals...

    Heels down on those down hill drops,,

  27. #27
    mtbr member
    Reputation:
    Join Date
    Jun 2014
    Posts
    8
    As this is my first post, I would like to thank you all for your input. I had never considered stem length and it's importance. I will be checking my bike to see how it fairs in current state.

  28. #28
    mtbr member
    Reputation:
    Join Date
    Sep 2009
    Posts
    4
    I ran upon this thread trying to decide if I needed a shorter stem.

    Just my less qualified experince and 1cents worth:
    1. The Line of sight method of the hub and handlebar relationship is a very loose starting point in my experience. On my bike, that would mean the bar would need to be against the stem; bringing the arms far to close in.

    2. As mentioned riding style. During my introduction to single speed where I am standing quite a bit, A longer stem allows me to stand more neutral/balanced and still keep my arms out a bit.

    3. Back to bike geometry: my 18inch Lynskey has a compact wheelbase and cockpit. Again, a significantly shorter stem would cause problems.

    I think the best advice I read was start with a slightly shorter stem and work from there.

    Thank for the input.

  29. #29
    mtbr member
    Reputation:
    Join Date
    Oct 2011
    Posts
    70
    Quote Originally Posted by erginguney View Post
    The basic principles of which I'm aware are these:


    • The longer the stem; the slower, more imprecise, and more stable the handling. The shorter the stem; the more agile, more twitchy, and quicker the handling. The reason is not too difficult to understand, if you imagine exaggerated scenarios. Think of having a 24-inch stem. In order to effect a 30-degree turn of your front wheel, you'd be sweeping the handlebar through several inches of of side-to-side motion. If your stem is only half-an-inch long, on the other hand, the arc swept by the mount point of your handlebar on that stem will be only a fraction of an inch long for that same 30-degree turn. Similarly, it's harder for a trail obstacle to deflect your wheel when your stem is longer, because the angular momentum it has to work against (your grip on the handlebar) is being applied at a larger distance from the point where the rotational force is applied (the head tube).



    • A longer stem will also imply a longer "cockpit" (seat-to-handlebar distance), which is considered to be better for racing or climbing, since it's a bit more conducive to applying a larger force on the pedals. I believe this is because it makes leaning forward a little easier and leaning forward allows you to pedal harder. The drawback of this would be that biking for long periods of time in that forward-leaning pose is fatiguing and would not be as comfortable as a more upright posture if you do extra long rides frequently. (The "more relaxed" feel you have in mind might be arising from this posture comfort, rather than in terms of "relaxed steering". The steering will, in fact, become more on-edge and nervous, with a shorter stem--comparatively speaking.) Conversely, with a shorter cockpit, you might be tempted to stand more frequently when the need arises to pedal harder.

    The above is very interesting! I went to a 45mm stem from a 70mm, whilst the 45mm went okay for 6 months or so the front wheel has span out twice recently (im now typing this with a cast on my wrist!). I'm going back to a 70mm when i've recovered. I definately thing a 70mm is much more forgiving and gives me more movement over the cockpit but i certainly wouldn't want anything over this.

    the 40-45 certainly seem alot less forgiving on cornering etc and sometimes i just like to slack a bit and ride

  30. #30
    mtbr member
    Reputation: Phinias's Avatar
    Join Date
    Aug 2014
    Posts
    333
    I am sure it has been mentioned in other threads, but I highly ecommend getting a professional bike fitting. It takes 2-3 hours and lasers and all kinds of other torture devices are used, but in the end you will have recomendations on everything from proper stem length to even crank arm lengths and saddle and grip recomendations. I did this as I have had 4 back surgeries and was using biking to help get my old, tired, and fat ass back into some semblance of shape. They even go over medical conditions such as previous broken bones and common aches and pains and take that into consideration. I could not more highly recommend this service, especially for a beginner.

  31. #31
    Rock n' Roller
    Reputation: snowgypsy's Avatar
    Join Date
    Jun 2011
    Posts
    269
    +1 for bike fitting. Actually +2 for bike fitting.
    Your style of riding, the type of riding that you like, and your bike fit play a big part in what stem length you enjoy. Like all things bike, it's a give and take. You gain some things while sacrificing others when you go long or short. Only you can decide if the sacrifice is worth the gain. That begin said, stem length also plays a big role in the fit of your bike. A shorter stem that enables your bike to fit you properly will feel more stable than a long stem.

  32. #32
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    I have a drawer full of stems! Trial and error but it has to be done. You will never figure out the best stem length for you by asking advice. You need to try them.

  33. #33
    mtbr member
    Reputation: Trail_Blazer's Avatar
    Join Date
    May 2012
    Posts
    2,162
    True ^^^^

  34. #34
    mtbr member
    Reputation:
    Join Date
    Jan 2015
    Posts
    7
    Here's just my two cents. I don't have a specific riding style. I love to climb and with fast downhills. I also ride single track and technical stuff sometimes.

    The main thing I want to point out here is to just be careful when changing up stem/handle bar lengths. This is especially true if you have been riding with a certain set up for a long period of time. There are definitely some benefits to wider bars and shorter stems, but as mentioned before, individual body mechanics get used to a certain position over time.

    For 20 years I had my set-up very narrow, 420mm bars with a 120mm stem. No one would ever set a bike up that way now, but the idea was to have strong climbing and it was great for that. I had no problems with downhill speed. The main reason I changed up was for fatigue and circulation problems in certain areas. Wider, 730mm riser bars helped right away with that. The problem was that the long stem did not work well with the wide bars. Crazy tire wander and trouble steering. I decided to move to a 100mm stem. That improved things some what.

    Then the real problem occurred, I moved to a 50mm stem. This all happened with 45 days or so. This was a big mistake. My body was just not prepared for the change. The problem was with climbing. I was so back heavy and so accustomed to pulling hard with my upper body that it was crazy squirrelly.

    Long story (ha) short I couldn't keep my front tire down, fell backwards and broke my wrist.

    I have been riding off-road for 30 years. That's right, I was on the trail back in the old days. So my experience level is high. I have plenty of war-wounds but nothing like this has ever happened. It is 100% due to the stem length and bar width. Wrong set-up for me and also too much too fast.

    So be careful and take it slow!

    I cut my bars to 680mm and run a 100mm stem, which is perfect for me.

  35. #35
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by Travis McOuat View Post
    Then the real problem occurred, I moved to a 50mm stem. This all happened with 45 days or so. This was a big mistake. My body was just not prepared for the change. The problem was with climbing. I was so back heavy and so accustomed to pulling hard with my upper body that it was crazy squirrelly.
    I guess there are advantages and disadvantages to both long/narrow and short/wide. I've tried both and for me the bottom line is that I can live with the times short/wide is not ideal but I cannot accept the problems a long stem causes.

  36. #36
    mtbr member
    Reputation:
    Join Date
    Jan 2015
    Posts
    7
    Quote Originally Posted by Mr Pig View Post
    I guess there are advantages and disadvantages to both long/narrow and short/wide. I've tried both and for me the bottom line is that I can live with the times short/wide is not ideal but I cannot accept the problems a long stem causes.
    Yeah, it does come down to each rider. At 43 I can only do so much to "retrain" my body to pull less on the climb, so too wide/short is just not a good deal. That said, flat 480/120 wasn't working for ride comfort, so 680/100 is a perfect compromise. My main concern is someone else having the same problem. A broken wrist is a major injury that took me out for quite a while. I simply couldn't keep the front wheel straight or on the ground because of my riding style. Really sucked...

    Thanks for the response!

  37. #37
    mtbr member
    Reputation:
    Join Date
    Jun 2014
    Posts
    270
    I went through stem changes and bar width changes and here is what I learned. Your torso and arm length combines with the bikes cockpit size (length from seat to stem) to determine what stem length you need. I you are a big buy on a small frame, you will need a longish stem (100 mm). Everyone needs a certain distance from their seat to their hands. It is specific to your body dimensions. If the stem on your bike doesn't put the seat and bars at that distance, it is not right and should be changed. Once you figure out the distance for you, it won't change much from one bike to another.

    Me, 6'4", short torso, long arms and legs. I bought a 22" frame with a 110 mm stem. Way too long for me. I felt way to stretched out and forward. I changed to a 40mm stem and 750mm bars and I love it. It is the right distance for me. How can you tell whats right for you, get a fitting, or sit on your bike and put your arms and hands in a natural comfy riding position (close you eyes and do what feels good). Open your eyes and see where your hands are relative to where your bars are and figure out what bar/stem combo gets you there. Some shops have variable stem fixtures to allow you to try different positions.

  38. #38
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by Bttocs View Post
    Your torso and arm length combines with the bikes cockpit size (length from seat to stem) to determine what stem length you need.
    I don't agree. Maybe the inch or two difference in stem will aid comfort but the main reason I use a short stem is handling. A short stem feels far more direct, stable and responsive on tight, rough trails.

  39. #39
    mtbr member
    Reputation:
    Join Date
    Jun 2014
    Posts
    270
    I agree with you about a short stem. What you describe are the added benefits of using a short stem. If your cockpit is too short however with a 80 mm stem, going to a 40 mm stem will only make it worse and possibly the bars will start hitting your legs. The solution is get a big enough frame size so you can use a short stem. Or find a bike with a longer cockpit for the same size frame that allows the shorter stem.

    There are both ergonmic considerations and handling considerations to factor in.

  40. #40
    mtbr member
    Reputation: MPX309's Avatar
    Join Date
    Nov 2014
    Posts
    242
    I have a short stem, I can't climb in a straight line lol.

  41. #41
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by MPX309 View Post
    I have a short stem, I can't climb in a straight line lol.
    A few people have said that sort of thing but I don't get it?

    The whole point of having a short bike is that it lets you move around and get your weight anywhere you want. I really like that. I can sit over the back wheel and almost lift the front end round tight corners but going up steep hills I can still lean over the bars and keep the front down no problem.

    So I don't get it? Am I special in having arms that bend in the middle or something? ;0)

  42. #42
    mtbr member
    Reputation:
    Join Date
    Sep 2014
    Posts
    197
    Quote Originally Posted by Mr Pig View Post
    A few people have said that sort of thing but I don't get it?

    The whole point of having a short bike is that it lets you move around and get your weight anywhere you want. I really like that. I can sit over the back wheel and almost lift the front end round tight corners but going up steep hills I can still lean over the bars and keep the front down no problem.

    So I don't get it? Am I special in having arms that bend in the middle or something? ;0)
    My problem is mainly with steep grades (>17%) and extended climbs on loose dirt. You can move your body around, but that requires climbing out of the saddle, which isn't very compatible with longer climbs.

  43. #43
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by gsa103 View Post
    My problem is mainly with steep grades (>17%) and extended climbs on loose dirt. You can move your body around, but that requires climbing out of the saddle, which isn't very compatible with longer climbs.
    Not really. I sit on long climbs, you just lean forward, slide forward on the seat if you have to. I'm just not finding this an issue.

  44. #44
    mtbr member
    Reputation: MPX309's Avatar
    Join Date
    Nov 2014
    Posts
    242
    Quote Originally Posted by gsa103 View Post
    My problem is mainly with steep grades (>17%) and extended climbs on loose dirt. You can move your body around, but that requires climbing out of the saddle, which isn't very compatible with longer climbs.
    What he said. . . lol climbing is fine if you're out of the seat. However, it depends what sort of rider you are, to dictate your stem length.
    I only like to get to the top to go down, I'm not bothered about how fast I get up, and quite happy to get off and push some parts. For me having the shorter stem is worth it when it pays it's way on the descent and I feel much more comfortable and in control.

  45. #45
    Anytime. Anywhere.
    Reputation: Travis Bickle's Avatar
    Join Date
    Jan 2004
    Posts
    6,112
    gsa103, I don't understand. You can't move around while seated?
    Still a lot of roadie fit misinformation that just doesn't apply to mountain biking. If all your riding is on easy trails then sure stick with that crap and enjoy. Mountain biking while not always on mountains entails rough terrain and steep pitches. These are safer, faster, and more fun with a proper mountain bike set up. If you can't use a 50mm stem on your bike you have the wrong size frame. If you can't climb with a short stem, try more stretching or maybe yoga. It's just technique. Why handicap your bike with a long stem just because you haven't learned to climb with a short one.

    Do some reading.

    Lee Likes Bikes
    I got some bad ideas in my head.

  46. #46
    mtbr member
    Reputation: justwan naride's Avatar
    Join Date
    Oct 2008
    Posts
    487
    Haven't read through the whole thread but here are my thoughts regarding stem length.
    There are two aspects on sizing a stem, the first one is fit and the second is handling. Ideally, you want to optimize both by riding the correct length.of frame with a properly sized stem.
    Let's talk about handling first. A short stem will make steering faster, even twitchy if it's fast to begin with (in case of a steep head angle). It will also shorten reach and give you more room to move back and forth on the bike. Compared to a longer stem,it will also lighten the front wheel,so going too short may affect front wheel traction.

    Fit wise, too short or too long a stem may cause you back and/or neck pain due to being too stretched/cramped.

    Unfortunately, I'm not aware of any methods to properly size stems to people and frames,but have developed a feel if right and wrong for myself by fitting and riding different lengths on my bike.

  47. #47
    mtbr member
    Reputation:
    Join Date
    Jan 2015
    Posts
    7
    Quote Originally Posted by Travis Bickle View Post
    gsa103, I don't understand. You can't move around while seated?
    Still a lot of roadie fit misinformation that just doesn't apply to mountain biking. If all your riding is on easy trails then sure stick with that crap and enjoy. Mountain biking while not always on mountains entails rough terrain and steep pitches. These are safer, faster, and more fun with a proper mountain bike set up. If you can't use a 50mm stem on your bike you have the wrong size frame. If you can't climb with a short stem, try more stretching or maybe yoga. It's just technique. Why handicap your bike with a long stem just because you haven't learned to climb with a short one.

    Do some reading.

    Lee Likes Bikes
    Oh yeah, just some reading. You might notice "Travis Bickle" that people are here READING this thread. I have been MTBing since I was 12, that's 1983, how about you? A lot has changed since then, and for the better, but if you are going to tell me that if I can't ride a 50mm stem I should read and do yoga that's pure BS. I am so squirrelly climbing with a short stem I can't control the front wheel, that's just how I feel on the bike, yoga's not going to help me. I have the exactly OPPOSITE opinion than most people here, I will take stability over small gains in handling any day. My frame size is not the problem either.

    A shorter stem is probably best for most people, but not all, this is why they make different size stems. The bottom line is that everyone is different which is why a thread like this is only good for speaking in generalities and everyone should keep that in mind.

  48. #48
    mtbr member
    Reputation: targnik's Avatar
    Join Date
    Jan 2014
    Posts
    3,924
    Short stem(s) :ftw:

    Sent from my Kin[G]_Pad ™
    "Mountain biking: the under-rated and drug-free antidepressant"

  49. #49
    bike tester
    Reputation: syl3's Avatar
    Join Date
    Apr 2008
    Posts
    1,155
    Quote Originally Posted by Travis McOuat View Post
    Oh yeah, just some reading. You might notice "Travis Bickle" that people are here READING this thread. I have been MTBing since I was 12, that's 1983, how about you? A lot has changed since then, and for the better, but if you are going to tell me that if I can't ride a 50mm stem I should read and do yoga that's pure BS. I am so squirrelly climbing with a short stem I can't control the front wheel, that's just how I feel on the bike, yoga's not going to help me. I have the exactly OPPOSITE opinion than most people here, I will take stability over small gains in handling any day. My frame size is not the problem either.
    No the problem is your technique, you need a longer stem to force you to put your weight more forward because you cant do it based on core strength alone.

    When i climb i am barely touching the bars or strangling the grips, it's just a light touch for steering as if i'm holding a cup of espresso between my fingers. You should try that, practice holding the weight of your upper body with your core so that you won't fall on your nose if someone sweeps your hands from under you. Once you can hold your weight you'll be able to position it as far forward as needed by leaning over the front of the bike, without actually relying on the stem or bars to put you in the right place.

  50. #50
    mtbr member
    Reputation:
    Join Date
    Aug 2014
    Posts
    106

    stem length: Please educate me?

    Quote Originally Posted by Osco View Post
    The simple set up for new riders:

    Get on your bike and ride,,,

    Look down at your front axle,

    If Its behind your bars you need a shorter stem,

    If the axle is visible in front of your bars you need a longer stem.

    Going shorter often needs a wider bar and more stem rise...

    DON'T go nutzoid,,,, Think baby steps.....

    Got a 90 mm stem go to a 75, NOT a 50, your a new rider remember !!

    The bike's geometry will change dramatically if you chop stem length by 40 to 50%

    Got a 7 degree rise, going from a 90 mm to a 75,,, try a 15 degree rise...
    The above changes dictate a bar change provided your not a small person..

    From a 90mm stem to a 70 or a 75 mm stem then 26"/660 mm handlebar
    should become a 28 or 29"/700/711 mm bar...

    Expert riders go radical,,,,,
    1st and second year barnstormers need small changes...

    Wider bars will open your lungs up a little, you will breathe better,,,

    Wider bars smack trees more often, you know, them crazy rodeo style get offs XD
    Smacked 3 trees in 2 days and got bucked off, luckily no damage to anything except my pride!


    Sent from my iPhone using Tapatalk

  51. #51
    mtbr member
    Reputation: J.B. Weld's Avatar
    Join Date
    Aug 2012
    Posts
    7,523
    Honestly not everyone wants or needs a 50mm stem, some of us are build differently and/or have different riding styles. I'm a gangly mofo and 80mm felt a little tight on my last bike, I'll see how it goes with my new upcoming ride but I'm not going to sacrifice what feels right to me just so I can be one of the cool kids and ride a 50mm.

  52. #52
    mtbr member
    Reputation:
    Join Date
    Mar 2013
    Posts
    400
    N
    Quote Originally Posted by Travis Bickle View Post
    gsa103, I don't understand. You can't move around while seated?
    Still a lot of roadie fit misinformation that just doesn't apply to mountain biking. If all your riding is on easy trails then sure stick with that crap and enjoy. Mountain biking while not always on mountains entails rough terrain and steep pitches. These are safer, faster, and more fun with a proper mountain bike set up. If you can't use a 50mm stem on your bike you have the wrong size frame. If you can't climb with a short stem, try more stretching or maybe yoga. It's just technique. Why handicap your bike with a long stem just because you haven't learned to climb with a short one.

    Do some reading.

    Lee Likes Bikes
    Truth. People used to think you needed a long stem for climbing to weight the front. But a long stem handicaps descending because weight on steeps is too much over the front contact patch. And it's not that you want to weight the front, but you want your weight in front of the rear contact patch. What the trend is now is longer bikes that work well with short stems. Wider bars also allow shorter stems. Wide bars lean you forward more and slow the steering and provide better leverage.

  53. #53
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    For me the stem length has nothing to do with fit. It is all about stability and control.

    Take two bikes out to your back yard/garden, one with a long stem and one with a very short stem. Try doing figure-eights on them both and see which one feels the most stable and lets to turn the tightest circles. I'll be a dribbling hamster humper if it's the long stemmed bike!

    It's very simple. Draw a circle on a piece of paper to represent the steerer on the bike. To represent an ultra-short stem, draw a line straight across the circle. With another circle draw a line above it at some distance with a line connecting the line to the circle, like an exaggerated long stem. Now imagine holding those bars and think about the direction in which you would have to apply force to rotate the stem.

    With the short stem you'll see that you have to push the 'bars' backwards and forwards to turn the stem, as you would expect. The long stem is different. The movement of the bars away from the steerer means that you now have another lever in the equation. In addition to front/back force you can now also turn the steerer by pushing the bars left and right!

    So you have more leverage, but I wouldn't call it better. Shifting your body weight left and right is now more likely to exert unintentional steering force on the bars and the greater leverage means even slight pressure will move them.

    On tight, technical riding short stems feel better because the bars turn only when you want them to. You feel more in control and the bike feels more stable. This is why BMX bikes don't have long stems!

    If you're not making big steering inputs and leaning forward on the bars a long stem will feel more stable as pushing forward on a long stem uses the advantage of that extra leverage to hold the front wheel more firmly, so it feels less squirmy at speed. Notice the length of the stems on road bikes?

    Everyone's different and if you love the way your bike rides that's all that matters, whatever the length of your stem. I can't deal with long stems at all. years ago a guy brought his bike over because it wasn't shifting properly. I rode the bike up the drive and turned tightly at the top, something I've done dozens of times, and I fell off the bike! It was only later as I was thinking 'How the heck did I manage that?' that it dawned on me that he had a really long stem. I realised that on every bike I've had I remove the stem and fit a short one. I can't ride long stems! Not if I want to go around corners anyway.

  54. #54
    mtbr member
    Reputation: targnik's Avatar
    Join Date
    Jan 2014
    Posts
    3,924
    Stem length is the icing on the cake. If geo is shite, putting a 50 on it won't really change much ^^

    Sent from my Kin[G]_Pad ™
    "Mountain biking: the under-rated and drug-free antidepressant"

  55. #55
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by targnik View Post
    Stem length is the icing on the cake. If geo is shite, putting a 50 on it won't really change much
    I don't agree. Changing the stem length just ten or twenty millimetres can make all the difference to how a bike feels.

  56. #56
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    150
    In general, i'd have to say that a frame with longer(ish) front center is going to have a cockpit that is more conducive to short stem/wide bar setup. So with that said, I guess i'd have to agree that Geo is a determining factor as to how I might setup a cockpit.

  57. #57
    mtbr member
    Reputation: targnik's Avatar
    Join Date
    Jan 2014
    Posts
    3,924

    Re: stem length: Please educate me?

    @Mr Pig

    A shit bike... is a shit bike.

    If you buy shit bikes, good for you.

    If you think a 50mm stem will make your shit bike awesome! Good for you...

    I'd rather buy a good bike and make it better with a shorter stem

    -------------------------------------
    Opinions are like A-holes... everybody
    has one & they're usually full of...??
    "Mountain biking: the under-rated and drug-free antidepressant"

  58. #58
    I have Flat Pedal shame.
    Reputation:
    Join Date
    Nov 2011
    Posts
    528
    Short stem and wide bars is game changing, no matter what bike you are on.
    We don't ride to add days to our life, we ride to add life to the days we have left here.

  59. #59
    mtbr member
    Reputation: andrewkissam's Avatar
    Join Date
    Jan 2014
    Posts
    128
    Some of it comes down to personal preference/riding style and some of it comes down to bike fit. I recently swapped the 90mm stem on my bike out for a 60mm stem and let me tell you it made a world of difference for me. My bike now feels completely different (in a good way), body position is more relaxed, steering is more precise, cornering is snappier, descending has become easier, the list could go on. Part of it is just experimenting with different lengths until you find something you like. Go to your LBS and see if they'll let you borrow a few stems to test out on your own rig.
    Keep the rubber side down

  60. #60
    mtbr member
    Reputation: Wittgenstein's Ghost's Avatar
    Join Date
    Oct 2014
    Posts
    311
    Quote Originally Posted by targnik View Post
    @Mr Pig

    A shit bike... is a shit bike.

    If you buy shit bikes, good for you.

    If you think a 50mm stem will make your shit bike awesome! Good for you...

    I'd rather buy a good bike and make it better with a shorter stem

    -------------------------------------
    Opinions are like A-holes... everybody
    has one & they're usually full of...??
    Wow, do you actually think any of that was implied by what he said? Or do you just enjoy pretending to not comprehend things in order to take a jab at someone?
    "Plato is my friend, Aristotle is my friend, but my best friend is truth." - Newton

  61. #61
    Mantis, Paramount, Campy
    Reputation: Shayne's Avatar
    Join Date
    Jan 2004
    Posts
    4,670
    Quote Originally Posted by Thustlewhumber View Post
    Short stem and wide bars is game changing, no matter what bike you are on.

    Like it makes me want to find a new game to play? Check!

    First thing to go in the bin if I bought a bike tomorrow would be the ridiculously short stem and ridiculously wide bars.

    It's all personal preference. Everyone out there should try different set-ups at some point to see what works for them.
    *** --- *** --- ***

  62. #62
    mtbr member
    Reputation:
    Join Date
    Jan 2008
    Posts
    719
    Quote Originally Posted by Thustlewhumber View Post
    Short stem and wide bars is game changing, no matter what bike you are on.
    I agree completely. I think some people still look at those bar and stem as fit devices to put them in the optimal power position, like how a road bike is fit, and that destroys the handling of the bike if they ride challenging terrain. Some bike shops who do fittings based on old road models do a real disservice to riders when they walk out with a bike that "fits like a glove" with a 100mm stem....as that bike with modern geo will never handle decently set up like that....IMO.

  63. #63
    Anytime. Anywhere.
    Reputation: Travis Bickle's Avatar
    Join Date
    Jan 2004
    Posts
    6,112
    Quote Originally Posted by Haymarket View Post
    I agree completely. I think some people still look at those bar and stem as fit devices to put them in the optimal power position, like how a road bike is fit, and that destroys the handling of the bike if they ride challenging terrain. Some bike shops who do fittings based on old road models do a real disservice to riders when they walk out with a bike that "fits like a glove" with a 100mm stem....as that bike with modern geo will never handle decently set up like that....IMO.
    Very true. If you have to have 70mm+ of stem to fit then the frame is too short, especially for new riders. A newbie doesn't have the skill yet, so why handicap them with a long stem which puts their weight too far forward. As for weighting the front end for climbing and cornering, elbows bend.

    We were talking about this on a rude the other night. Friend said he wished he could go back to the 80's with what he knows now about mtb fit and handling. I watched that video of the 90's DH crashes. Long stems, narrow bars, and high saddles = scabs.
    I got some bad ideas in my head.

  64. #64
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    I've noticed that some bike manufacturers are now sizing their bikes based on a short stem, so the top-tube is longer than it used to be for each given frame size.

  65. #65
    mtbr member
    Reputation:
    Join Date
    Sep 2009
    Posts
    255
    I have a steel mongoose 29er singlespeed with a bmx style stem and risers. That thing is an absolute joy to ride! I can go hours non-stop with zero back ache.

    I also have a Schwinn 29er that's a size bigger so I'm trying to match the reach and fit as close as possible. It already has a 70mm stem, but I'm trying out a 40mm one.

  66. #66
    Trail Ninja
    Reputation: Varaxis's Avatar
    Join Date
    Mar 2010
    Posts
    4,653
    I swapped to a 35mm stem for a month or 2 and found the bike doesn't do so well on the climbs, lacking weight on the front end. Any rock gardens I pedaled through on the climb part was a real challenge, as it was hard to control the front. It made the rock gardens fun on the descent, but after putting the stock 60mm back on, I found a nice balance of climb/descend ability.

  67. #67
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    6,613
    Quote Originally Posted by Mr Pig View Post
    I've noticed that some bike manufacturers are now sizing their bikes based on a short stem, so the top-tube is longer than it used to be for each given frame size.
    but many don't, and still increase the ST by 2" for every 1" in TT length, making it difficult to upsize even if you want to.

  68. #68
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by Varaxis View Post
    I swapped to a 35mm stem for a month or 2 and found the bike doesn't do so well on the climbs...after putting the stock 60mm back on, I found a nice balance of climb/descend ability.
    I think my stem is 50 or 60, I can't remember, but of course the position of the bars will add or take away from the effective length of the stem as well.

    Quote Originally Posted by fsrxc View Post
    but many don't, and still increase the ST by 2" for every 1" in TT length, making it difficult to upsize even if you want to.
    I like it when the give you the full geometry of the bike in a little diagram so you can see exactly how it will measure up, or get a good idea anyway.

  69. #69
    squish, squish in da fish
    Reputation: fishwrinkle's Avatar
    Join Date
    Jul 2012
    Posts
    1,635
    Quote Originally Posted by Phinias View Post
    I am sure it has been mentioned in other threads, but I highly ecommend getting a professional bike fitting. It takes 2-3 hours and lasers and all kinds of other torture devices are used, but in the end you will have recomendations on everything from proper stem length to even crank arm lengths and saddle and grip recomendations. I did this as I have had 4 back surgeries and was using biking to help get my old, tired, and fat ass back into some semblance of shape. They even go over medical conditions such as previous broken bones and common aches and pains and take that into consideration. I could not more highly recommend this service, especially for a beginner.
    LOL where might i get this done? you must have found the mecca of all lbs's

  70. #70
    squish, squish in da fish
    Reputation: fishwrinkle's Avatar
    Join Date
    Jul 2012
    Posts
    1,635
    Quote Originally Posted by Mr Pig View Post
    I've noticed that some bike manufacturers are now sizing their bikes based on a short stem, so the top-tube is longer than it used to be for each given frame size.
    i purposely size up on most frames if it will allow for this

  71. #71
    squish, squish in da fish
    Reputation: fishwrinkle's Avatar
    Join Date
    Jul 2012
    Posts
    1,635
    like travis said, if you need to climb, bend your elbows with chest to the steerer and nose of saddle in ur d!ck and grind it out. sounds like a bunch of roadies in here. or if your're a ss guy stand and mash like me. sounds like the pussification of america is taking hold on a lot of people

  72. #72
    mtbr member
    Reputation: RS VR6's Avatar
    Join Date
    Mar 2007
    Posts
    3,781
    I ride road and dirt. Fit on a road bike is more static...you're pretty much in one position and the terrain never changes. A mountain bike is much more dynamic as in body position and terrain.

    My road bike runs a 110mm stem and a 38cm bar.

    Stem length is pretty personal on any bike. AM or Trail seems to be around the 50-60mm in length. Park/Freeride around 35mm. XC is much more different. I use a 66mm Flatforce stem and 710mm Niner bar on my 29HT. Some XC racers ride real aggressive positions. As in 100mm+ lengths.

    I tired the 35mm stem and 780mm bar on my 26 FS. Its a bike that goes down more than up. The short stem and wide bar did not work for me. I'm 5'8" and about 145lbs all geared up...not a big guy. The 780 bar felt like a broomstick and the steering felt dead. I finally settled on a 50mm stem and 750mm bar.

    As with anything that you have to dial in...it'll take time and experimentation...and some $$$.

  73. #73
    squish, squish in da fish
    Reputation: fishwrinkle's Avatar
    Join Date
    Jul 2012
    Posts
    1,635
    vr6, sounds like the stem and bar length i use, so yeah it sounds like you're doing a wide spread pushup on every ride with that setup. i'm 6'3" and use a 50mm with a 760 bar. reach 18.5 stack 25.5

  74. #74
    mtbr member
    Reputation:
    Join Date
    Sep 2009
    Posts
    255
    I just tried a 40mm stem on my 29er and it felt great going downhill. Steering was direct as hell but too twitchy for my liking. Climbing was alright since I normally stand or lean forward anyway. But it felt less stable and a bit squirrelly especially when transitioning body position.

    Switched back to a 65mm stem. Feels more natural.

  75. #75
    I have Flat Pedal shame.
    Reputation:
    Join Date
    Nov 2011
    Posts
    528
    I think everyone here can agree that "heavy feet, light hands" is the best way to mountain bike, which means that most of your weight should be in your feet over the bottom bracket and not leaning on the bike with your hands. That theory doesn't go away suddenly when you are climbing: you still have to keep all your weight driving through your bottom bracket. If your front end is lifting while climbing, it either means you are pulling on your bars or your weight isn't far enough forward. It has nothing to do with your stem.
    We don't ride to add days to our life, we ride to add life to the days we have left here.

  76. #76
    squish, squish in da fish
    Reputation: fishwrinkle's Avatar
    Join Date
    Jul 2012
    Posts
    1,635
    i'm in the process of welding my bars to my steerer right now, i'll let you guys know how i can rip it up and down hill. so if i'm riding my unicycle can i only go down hill, but it is a 36" wheel?

  77. #77
    mtbr member
    Reputation: jtempest's Avatar
    Join Date
    Apr 2014
    Posts
    26
    I'm 6'0" and just swapped out my stock 100mm stem 620mm bars for 70mm stem 700mm bars. It was noticeably easier to maintain control down a rocky decent, yet slightly more difficult to climb.

    The shorter stem makes the whole bike feel A LOT smaller. I'm so surprised 30mm can make such a difference, and only now am I able to appreciate why people obsess over 1 degree differences in frame geometry and stuff. It really does matter.

  78. #78
    mtbr member
    Reputation: Wittgenstein's Ghost's Avatar
    Join Date
    Oct 2014
    Posts
    311
    Quote Originally Posted by Thustlewhumber View Post
    I think everyone here can agree that "heavy feet, light hands" is the best way to mountain bike, which means that most of your weight should be in your feet over the bottom bracket and not leaning on the bike with your hands. That theory doesn't go away suddenly when you are climbing: you still have to keep all your weight driving through your bottom bracket. If your front end is lifting while climbing, it either means you are pulling on your bars or your weight isn't far enough forward. It has nothing to do with your stem.
    I agree with "heavy feet, light hands" generally. However, during a climb (assuming you are either out of the saddle or we are ignoring weight on the saddle), putting your weight forward means putting weight on the handlebar, which is weight on the stem. There is no way to put more weight forward without putting additional weight on the stem. In such a case, the longer the stem, the greater the downward force on the front end of the bike (force increases as length of radius increases in a pivot). All else being equal, more downward force can be applied on a 100 mm stem than a 50 mm stem.

    That isn't to say that the difference in force requirements can't be overcome by rider adjustments, but there's no "free lunch" when you get that improved downhill ability (which comes from reduced force on the front end).
    "Plato is my friend, Aristotle is my friend, but my best friend is truth." - Newton

  79. #79
    DVC
    DVC is offline
    back in the saddle
    Reputation:
    Join Date
    Jun 2014
    Posts
    23

    stem length: Please educate me?

    Quote Originally Posted by Wittgenstein's Ghost View Post
    I agree with "heavy feet, light hands" generally. However, during a climb (assuming you are either out of the saddle or we are ignoring weight on the saddle), putting your weight forward means putting weight on the handlebar, which is weight on the stem. There is no way to put more weight forward without putting additional weight on the stem. In such a case, the longer the stem, the greater the downward force on the front end of the bike (force increases as length of radius increases in a pivot). All else being equal, more downward force can be applied on a 100 mm stem than a 50 mm stem.

    That isn't to say that the difference in force requirements can't be overcome by rider adjustments, but there's no "free lunch" when you get that improved downhill ability (which comes from reduced force on the front end).
    Best post in this thread so far... well-said.
    Stems aren't magic, they just facilitate positioning of rider weight.

  80. #80
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by DVC View Post
    Stems aren't magic, they just facilitate positioning of rider weight.
    Man, that is so wrong it's not funny!!

  81. #81
    mtbr member
    Reputation: J.B. Weld's Avatar
    Join Date
    Aug 2012
    Posts
    7,523
    Quote Originally Posted by DVC View Post
    Stems aren't magic, they just facilitate positioning of rider weight.

    Quote Originally Posted by Mr Pig View Post
    Man, that is so wrong it's not funny!!

    So stems are magic?

  82. #82
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    Quote Originally Posted by J.B. Weld View Post
    So stems are magic?
    Well maybe if your name is ET...

  83. #83
    DVC
    DVC is offline
    back in the saddle
    Reputation:
    Join Date
    Jun 2014
    Posts
    23

    stem length: Please educate me?

    Quote Originally Posted by J.B. Weld View Post
    So stems are magic?
    Lol

  84. #84
    mtbr member
    Reputation:
    Join Date
    May 2004
    Posts
    1,001
    I think theres way too much emphasis placed on stem lengths. Bar widths are debatable because the amount of leverage a particular rider requires will determine what they feel comfortable with. Many XC racers have gone wider because they can then loose upbody strength to save a kilo of body weight. This helps power to weight more than loosing a kilo off a top end bike.

    For Joe Pubic, the process of bike fit should always start with the frame you're trying to fit onto.
    Lets face it we don't always go for the frame most suited to our physical dimension. Often theres a deal that just too good to be true.

    Once we've decided what frame we need to establish if the front centre is long enough to allow your feet to cear the front wheel when the bars are turned throughout the compression and rebound strokes of the fork. I always tend to find a bike that gives me about 1cm clearance with the ball of my foot on the pedal axle on 175mm cranks. This is 1cm minimum through the forks stroke.

    Then determine where you need to sit to allow for good climbing power. often that can be a slightly forward saddle and the nose slightly down.

    Now you need to determine what stem gets the chosen bar into the space you need it to be comfortable. For me this is a top tube + stem length of 66cm-67cm.

    This typically means I can ride a small or a medium frame depending on manufacturer.

    I don't find any particular advantage to an overly long front centre but the smallest possible frame that allows foot clearance is must easier to handle on singlettrack climbs and is very controllable on descents because by moving my weight about I get a better and more positive response from the bike - less of that passenger feeling.

  85. #85
    mtbr member
    Reputation: Trail_Blazer's Avatar
    Join Date
    May 2012
    Posts
    2,162
    Stem length is about geometry for the riders comfort and control. Every rider on every bike have different needs and preferences. Some people can ride anything and feel comfortable some people need things to be just right for them to be comfortable there is no such thing as one solution for every person and every situation. The best solution in my opinion is to have a proper professional bike fitting and then have another one after 10 rides to help tune for your preference people who do proper bike fitting of this kind will often swap out your Stem your seat post and other things for different sizes to test with in the shop. Then you can choose to buy a new one or keep your old one after you see how it fits in the shop. Most professional bike fittings cost around $50 and can take 1 or 2 hours.

  86. #86
    mtbr member
    Reputation:
    Join Date
    Feb 2014
    Posts
    52
    Would someone be willing to summarize the effect of stem length / bar width on riding?

    I've read through all of the posts on this thread and several have touched on this, but again looking for a summary. I'm not talking about geometry and fit. I know there are a million variables. But I'm trying to isolate the stem length variable and how that translates to how a bike performs for different conditions. (Yes, I know changing one variable affects other variables)

    So suppose: My bike fits great. It's set up for "trail" meaning it does reasonably well for most conditions. How does a longer or shorter stem affect technical climbing? Technical descending? Getting through very technical stuff that requires a lot of balance, weight shifting, bunny hops, etc.?

    Thanks!

  87. #87
    mtbr member
    Reputation:
    Join Date
    Oct 2010
    Posts
    3
    I read through most of the comments and have a question that I don't think was addressed directly. I rode a number of demo bikes this year and noticed that some of the more "modern" bikes with slack head tube angles and shorter stems seemed to put the front wheel out ahead my body more and when going into a turn on the smooth high speed Giant Slalom trails we have around here the front tire did not seem to have as much traction as I have been used to. If you exaggerated that idea imagine riding a bike built like a motor cycle chopper and the lack of grip the front tire would have on a dirt track. So my question is how does stem length relate to where the bar is to the point of contact with the tire. So for me where I live the issue is not so much about having control on rocky descents as having traction at high speed in a corner on dirt with just enough suspension to keep the tires in contact. It seems to me that the extra quick control of a short stem is not really a big benefit for what I just described. In fact having something that is real twitchy might be a liability where you want to be making real subtle smooth corrections (not sudden or jerky) so as not to lose contact and wash out of the turn.

    There are other factors like body size and bike fit that used to be a factor in stem length but I am hearing a number of guys on this thread that you just need to pick a bike that fits you with a short stem. I have been in the shops and gotten the lectures on how we all need short stem wide bar slack angle bikes but maybe they are not the best for all conditions. I have to wonder if some of the people posting on this thread come from places where mountain biking is all about steep ascents and steep rocky descents - that is all they have available to them or all they want to ride.

  88. #88
    mtbr member
    Reputation: Mr Pig's Avatar
    Join Date
    Jun 2008
    Posts
    7,059
    When you're talking about cornering traction, climbing hairpins etc, the size of the stem is more about the way the steering feels than weight distribution. In these situations, the longer front end is harder, no doubt about it, but the stem length doesn't cause the issue. The bikes geometry does.

    While a shorter stem lets you get further back more easily you can still bend your arms and get as far forward as you like. The stem difference is only a few centimetres after all and the shorter stem and wide bars help to make the long nose more stable in all situations, not just descending.

    Everything is a compromise but short stems are a good one on a lot of bikes and for a lot of riding.

  89. #89
    mtbr member
    Reputation:
    Join Date
    Mar 2013
    Posts
    400
    Simply putting a short stem on a bike will not necessarily make it handle better. What you want is a frame that is long enough that a short 50 mm ish stem is the proper fit for you. People often think a long stem 100 mm or more, let's them climb better which is only true because of the position the lond cockpit puts you in. You aren't weighting the front, but putting your weight in front of the back wheel.

    Short stems allow the rider to put more weight on the front tire when cornering because you aren't putting the weight too far forward where you feel like your going over the bars. Long bikes and short stems work better in all situations. The bikes we rode 15 years ago with road style fit were stupid.

    Replacing a long stem with a short one on a bike that fits well in terms of saddle- bar distance won't be optimal.

  90. #90
    I have Flat Pedal shame.
    Reputation:
    Join Date
    Nov 2011
    Posts
    528
    Quote Originally Posted by ORMTB View Post
    I read through most of the comments and have a question that I don't think was addressed directly. I rode a number of demo bikes this year and noticed that some of the more "modern" bikes with slack head tube angles and shorter stems seemed to put the front wheel out ahead my body more and when going into a turn on the smooth high speed Giant Slalom trails we have around here the front tire did not seem to have as much traction as I have been used to. If you exaggerated that idea imagine riding a bike built like a motor cycle chopper and the lack of grip the front tire would have on a dirt track. So my question is how does stem length relate to where the bar is to the point of contact with the tire. So for me where I live the issue is not so much about having control on rocky descents as having traction at high speed in a corner on dirt with just enough suspension to keep the tires in contact. It seems to me that the extra quick control of a short stem is not really a big benefit for what I just described. In fact having something that is real twitchy might be a liability where you want to be making real subtle smooth corrections (not sudden or jerky) so as not to lose contact and wash out of the turn.

    There are other factors like body size and bike fit that used to be a factor in stem length but I am hearing a number of guys on this thread that you just need to pick a bike that fits you with a short stem. I have been in the shops and gotten the lectures on how we all need short stem wide bar slack angle bikes but maybe they are not the best for all conditions. I have to wonder if some of the people posting on this thread come from places where mountain biking is all about steep ascents and steep rocky descents - that is all they have available to them or all they want to ride.
    It comes down to a fundamental way of handling your bike. Mountain biking has historically gotten most of it handling information from road biking, and admittedly a lot of road bikers have made a transition over to mountain biking. Long stems, lots of weight on handlebars, "efficiency" in pedalling, etc all work very well in road biking.

    Recently, people have started to realize that mountain bike handling has more in common with motorcross than with road biking. Driving the bike with your hips, leaning the bike, being active in your movements up/down/side to side and not just statically sitting on your bike is starting to become more mainstream. This is where short stem/wide bars (and dropper) movement is coming from - driving the bike from your hips and only making small fine tuned corrections with your handlebars.

    To answer your question: its should be your back wheel that will give you your traction, not your front - but that depends on your riding style.
    We don't ride to add days to our life, we ride to add life to the days we have left here.

  91. #91
    mtbr member
    Reputation:
    Join Date
    Aug 2015
    Posts
    1
    Well this is very interesting....
    Having raced BMX for years, I can tell you that geometry, bar length, stem length etc is critical in setting up the bike to your body geometry. Every 5mm makes a big difference in the handling of the bike. My BMX race sweet spot is 48mm stem with 760mm bars, but this is a result of calculating the Rider Area and matching it to my body size.

    In 2013 a bought a Giant Reign 1 (M) which has a 70mm stem, first thing I did was fit a 50mm stem. But the bike handled like crap, front end kept washing out at speed on corners, put the 70mm back on and it was perfect. I prefer the positive handling of the short stem, but could not get the bike to hold the line no matter where my body was. So it came down the Top Tube and bike geometry was not suitable for a short stem.

    The 2015 Giant Reign has new geometry, TT is 25mm longer and it comes with a short stem. Problem solved, much better balance bike with the advantages of the short stem handling.

    So it all comes down to your ridding ability, frame geometry, trails ridden, preferred handling characteristics of the bike. I think Mondraker have set the new standard with the 'forward geometry' frames....