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  1. #1
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    Stem length question - anyone?

    I'm riding a size-Large hardtail XC 29er with a 120mm stem and a 620mm (24.4in) wide, 25mm rise handlebar. I recently demoed a full-squish 26er with a shorter stem and 690mm bar and really liked the quicker steering.

    I'm just guessing here but am I correct that a 100mm stem would quicken the steering on my bike? Any downsides?

    My thinking is that with a 100mm stem and bar about 670mm wide (plus or minus 10mm), I'd have better and faster control of the front end. I've read some magazine testers complaining about the narrow bars common on budget bikes. Seems to me that 620mm is on the narrow side for optimum control (though 690mm seemed like a tight squeeze between the trees! LOL.). TIA.
    Last edited by Clones123; 07-12-2010 at 11:39 AM.
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  2. #2
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    Steering will be twitchier at high speeds, but the wider handlebar should help. 20mm shorter will be a pretty dramatic change.

  3. #3
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    Quote Originally Posted by Clones123
    I'm riding a size-Large hardtail XC 29er with a 120mm stem and a 620mm (24.4in), 2.5-inch riser handlebar. I recently demoed a full-squish 26er with a shorter stem and 690mm bar and really liked the quicker steering.

    I'm just guessing here but am I correct that a 100mm stem would quicken the steering on my bike? Any downsides?

    My thinking is that with a 100m stem and bar about 670mm wide (plus or minus 10mm), I'd have better and faster control of the front end. I've read some magazine testers complaining about the narrow bars common on budget bikes. Seems to me that 620mm is on the narrow side for optimum control (though 690mm seemed like a tight squeeze between the trees! LOL.). TIA.
    You are on the right track as far as a shorter stem/longer bar combo being able to offer a bit more control/leverage - nice thing is the wider bars help keep your reach feeling ok if you shorten up the stem (as well as reducing your stem's rise can help reduce the effects of going with a shorter stem)
    Bar width is a personal preference for sure but 635-690 mm wide bars paired with 80-110mm stem for most trail/XC riding is a good start-. I run a bit different combo on each bike- 90mm w/ 635 bars on one and 100mm with 685 bars on the other - mostly because of top tube length but I also like a bit wider bars on my SS... it seems you have been reading a bit of MBA as I recall almost every test mentions bar width as an issue...
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  4. #4
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    Quote Originally Posted by knottshore
    it seems you have been reading a bit of MBA as I recall almost every test mentions bar width as an issue...
    I could have sworn it was MBR instead but I flipped through some recent issues and it was actually What Mountain Bike that got me onto the issue of shorter stems and wider bars.

    When I rode motorcycles it was the Brit magazines that were by far the best. Same with mountain bikes now - Mountain Bike Rider, Mountain Biking UK and What Mountain Bike each have awesome content (blunted somewhat by a fair amount of UK-specific content). Thing is, these foreign magazines are hideously expensive in the USA - like $10 an issue at a newstand.

    Not to highjack my own thread but what is it with the Brits anyway? They've got crap weather, insanely high prices and rampant bike theft and yet they ride bikes (both motor and pedal powered) as though their Island is some kind of biker's paradise. I admire the spirit - I just don't understand it. Kudos to you Brits and your mags!
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  5. #5
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    Quote Originally Posted by Clones123
    I could have sworn it was MBR instead but I flipped through some recent issues and it was actually What Mountain Bike that got me onto the issue of shorter stems and wider bars.

    When I rode motorcycles it was the Brit magazines that were by far the best. Same with mountain bikes now - Mountain Bike Rider, Mountain Biking UK and What Mountain Bike each have awesome content (blunted somewhat by a fair amount of UK-specific content). Thing is, these foreign magazines are hideously expensive in the USA - like $10 an issue at a newstand.

    Not to highjack my own thread but what is it with the Brits anyway? They've got crap weather, insanely high prices and rampant bike theft and yet they ride bikes (both motor and pedal powered) as though their Island is some kind of biker's paradise. I admire the spirit - I just don't understand it. Kudos to you Brits and your mags!
    I agree WMB and MBUK are great mags- tought to find sometimes and like you said $10 bucks pop! Ouch- grreat info though and no @ss kissing to anyone- just telling it as they see it.
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  6. #6
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    I think you may be feeling the difference in wheel size...29" HT to 26" squish. The 26" would probably have quicker steering characteristics all components being equal.

    Stem and bar will have the same kind of effect too! I think you will see a difference running the 100mm stem over the 120 on the 29er.

  7. #7
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    Short and wide

    Shorten that stem mate and reap the difference in handling. Hell l used to run 120/110mm stems with 690mm bar. More allround position rather than long and low for XC. I have been able to reduce (overtime) my stem to 90mm and bar increased to 750mms. going to try a 70mm stem. Love the increased control in technical terrian and have learnt to shift weight forward for the steep climbs. Ride Jones and Blacksheep bars on other rigs which l like but not for everyone.

  8. #8
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    Quote Originally Posted by johnd663
    I have been able to reduce (overtime) my stem to 90mm and bar increased to 750mms.
    750mm?! Whoa. I didn't know they made bars that wide. At least not for sale in North America. I'm pretty sure that standard spacing between pine trees in Georgia is less than 750mm (or at least it seems like it). Now, down in Melbourne no doubt a lot of things are different...

    Like, is "Foster's" really "Austrailian for beer" like they claim on TV?
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  9. #9
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    Damn straight

    Quote Originally Posted by Clones123
    750mm?! Whoa. I didn't know they made bars that wide. At least not for sale in North America. I'm pretty sure that standard spacing between pine trees in Georgia is less than 750mm (or at least it seems like it). Now, down in Melbourne no doubt a lot of things are different...

    Like, is "Foster's" really "Austrailian for beer" like they claim on TV?
    Foster Australian for beer, hell no, that stuff is cat piss that is only for export........ we dont drink it here....... send it overseas to prop up your cat piss beer market. There are many misconceptions about Australia floating around but we do train kangaroos to deliever mail in the outback and koalas kill more Aussies than White Sharks.
    Everyone here rides really wide bars. So much so that trails are built exactly 780mm wide for clearance or we learn to mono through trees while turning bars. Look at Sam Hill, Graves, Chris Kovorac (spelling), Rennie, Cadel and sick Mick. They all got good at riding downhill by learning to commute with really wide bars, hungover on Fosters smuggled in from US while avoiding koalas that drop from the surrounding trees and buildings and gauge out the riders eyes. Bit like the Johnny Cash sond "Boy named SUe" but instead once the trainer wheels come off the really wide bars go on and fend for yourself kid.
    Now l imagine things are alittle different here in Melbourne to North America. We have 8 of the top ten most deadly snakes on the planet, 6 of the worlds killer spiders and the koalas. If you want to ride a bike around here you have to be fast. Then add to that the fact that mountain bikers are like Gods / Godesses to the opposite sex and it is not uncommon to be ambushed by a bevie of beauties while riding to the shop. MTBer are often abducted and held as sex slaves for catwalk models who devour their prey like the Mountain Devil Roo native to the area.
    So if you want to get fast ......... chuck on some wide bars, an Australia Wallabies jersey and some extra iron tablets and go ride. Just watch out for the drop bears and swimsuit models.
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  10. #10
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    Back on topic I am a big fan of shorter stems I bought a 60mm to put on a Voodoo hardtail it's now on its third frame a Gunnar. A friend picked up a Salsa that came with a 120 he didn't really like the way it handled I think he's down to a 90 now. I put him in touch with a shop that I like to use the guy always keeps some extra stems on hand to allow for test rides until you figure out what works best. When I had a custom build done at this same shop they put me on a trainer to figure out a base line for stem length. When sitting in a comfortable position where are the bars in relation to the front axle. This is just a starting point but I find that if the bars are in front of the axle it feels like you will go over easier. If the bar covers the axle or is just behind it I feel I get a better ride.
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  11. #11
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    You are using 2.5" riser bars on an XC bike? That probably explains the crappy handling right there. Is the frame too small for you?
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  12. #12
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    Doh! 25mm riser bars is what I should have written. Fer cryin' out loud - I'm surprised no one else questioned that. Hardtail beach cruiser anyone?

    Here's a photo of the bike when it was still new. I've since inverted the stem to get the bars pretty much level with the seat. Perhaps "XC bike" (race?) doesn't descibe the bike as well to some as "Trail bike" would. Flat bars would be below seat height even with positive angle on the stem. I'd happily move to low-rise (10mm) bars but most of the bars I've seen for sale are either flat or 25mm rise.

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  13. #13
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    Quote Originally Posted by AZTtripper
    I find that if the bars are in front of the axle it feels like you will go over easier. If the bar covers the axle or is just behind it I feel I get a better ride.
    I hadn't thought much about the bar's position relative to the front axle but, now that you mention it, I have been over the bars several times in the past two months!

    Perhaps a shorter stem would lead to less wear on my helmet, eh?
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  14. #14
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    @johnd663:

    If everyone in Australia is as funny as you, I gotta get down there for a visit! Thanks for the laugh!

    (OP, sorry for the highjack)

  15. #15
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    That stem looks really long at least in my opinion.
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  16. #16
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    I'm trying to understand these claims from a physics point of view. A shorter stem gives you more control? quicker steering? Twitchier? More stable?

    WHY?
    Please discuss:

  17. #17
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    Quote Originally Posted by smilinsteve
    I'm trying to understand these claims from a physics point of view. A shorter stem gives you more control? quicker steering? Twitchier? More stable?

    WHY?
    Please discuss:
    c=2Pi * r where r is the radius (or stem length) and c is the circumference of the circle (or arc of the stem). Longer stem = more arc to cover.

    <this sounded better in my head than it looks in this post>

  18. #18
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    Quote Originally Posted by noah19692000
    c=2Pi * r where r is the radius (or stem length) and c is the circumference of the circle (or arc of the stem). Longer stem = more arc to cover.

    <this sounded better in my head than it looks in this post>
    More arc to cover, yes. So more hand movement for a given tire movement. (Good or bad?)
    On the flip side, longer lever to resist forces that try to turn your wheel.
    I think this is a good beginning to the analysis. Please continue...

  19. #19
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    Quote Originally Posted by noah19692000
    c=2Pi * r where r is the radius (or stem length) and c is the circumference of the circle (or arc of the stem). Longer stem = more arc to cover.

    <this sounded better in my head than it looks in this post>
    Hey when I look at your post, it doesn't contain a sentence that appears when I quote your post, which is:
    this sounded better in my head than it looks in this post
    Why is it not visible except when quoting? And then when I post with your quote on there, it doesn't show up????

    Is it the > symbols?

  20. #20
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    Quote Originally Posted by noah19692000
    c=2Pi * r where r is the radius (or stem length) and c is the circumference of the circle (or arc of the stem). Longer stem = more arc to cover.

    <this sounded better in my head than it looks in this post>:skep:

    Test test

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  21. #21
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    Recently, there was a Fisher demo day in my area. I wanted to try the Superfly 100 but there was only a Hifi Deluxe XL. I didn't want to wait. I'm 5'10" so the rep put a super short stem. I thought it would be awful. NO, I felt better and ride faster than never before. I was so shocked that I returned to the demo a second time in the evening to test again. Same conclusion. After that day I went from a medium frame (59 ETT / 1109mm wheelbase) with 90mm stem to a XL frame (63.8 ETT / 1156 wheelbase) with 40mm stem. Since, no more fear to go over the bar (front wheel further forward and the handlebar is way behind the front axle), MUCH more stable downhill because of longer wheelbase, MUCH MUCH faster over rough stuff (less weight on the front wheel, it's easier to roll over obstacles), MUCH faster when I stand up and sprint (less weight on the front wheel, less suspension movement absorbing my power. Now I feel I'm "inside" the bike, in the middle of bike instead of being over the front wheel. The bars are levelled with the saddle before they were under.

    Actually I just went from a "XC race" position to a "trail bike" position. I never expected that would help me being a faster rider. My friends were very skeptical with these drastic changes but now after few rides they are eating mys dust Day and night.
    Attached Thumbnails Attached Thumbnails Stem length question - anyone?-134-3448_img.jpg  


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    Quote Originally Posted by Jim311
    You are using 2.5" riser bars on an XC bike? That probably explains the crappy handling right there. Is the frame too small for you?
    Can you explain how bar height affects handling? I just ordered a Trek Cobia 2011 which has a flat bar. I have a Bontrager Earl Riser (50 mm) riser laying around. The Cobia will definitely be the correct size for me. I'm *thinking* of installing the Earl onto my Cobia because I generally like my handlebars a little higher presumably for extra comfort. If the riser messes up the handling then I won't swap as I don't really need to. I see a lot of mtn bikes with risers like the Trek 6000.

  23. #23
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    MYTH,

    The stem doesn't directly change the steering speed, what it'll do though is when going DH out of the seat it'll move your weight further back, also while riding there will be less weight over the front wheel, which might make it seem faster, this isn't good in muddy conditions mind.

  24. #24
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    Highjack away my friend - add some spice

    Quote Originally Posted by golden boy
    @johnd663:

    If everyone in Australia is as funny as you, I gotta get down there for a visit! Thanks for the laugh!

    (OP, sorry for the highjack)
    Oh thanks oh golden one. I wish you could be here too as it gets lonely at times as all my friends are injured from crashes involving clipping trees will stuppidly wide bars. Suffer for your art.

    To the OP - just post a picture of you sitting on your bike and all the e-egomonical specialists will point you in the right position. There is no hard or fast rule - just what ever works for the majority of your riding.

  25. #25
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    stem length is about fine tuning fit not so much about handling. Fit>***

  26. #26
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    Quote Originally Posted by customfab
    stem length is about fine tuning fit not so much about handling. Fit>***
    Quote of the day. It's about finding a balance over the bike. Wether it's a 60mm or a 130mm it's about placing the rider in the optimal position.

  27. #27
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    Quote Originally Posted by customfab
    stem length is about fine tuning fit not so much about handling. Fit>***
    Thank you. All the comments about stem length and handling is rubbish. People wanting short stems is rubbish as well....go to a smaller frame.
    I ride a Large 29er hardtail with 130mm stem and the handling and my CG on the bike is perfect. One size does not fit all.
    If you want to ride a big bike with short stem because you want a taller head tube that's fine as well. Stem length as you say is for fit tuning and not to tune handling. Yes fit is about CG on the bike which will affect the weight on the front wheel.

  28. #28
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    Quote Originally Posted by common_man
    Can you explain how bar height affects handling? I just ordered a Trek Cobia 2011 which has a flat bar. I have a Bontrager Earl Riser (50 mm) riser laying around. The Cobia will definitely be the correct size for me. I'm *thinking* of installing the Earl onto my Cobia because I generally like my handlebars a little higher presumably for extra comfort. If the riser messes up the handling then I won't swap as I don't really need to. I see a lot of mtn bikes with risers like the Trek 6000.

    I'll post my experience, since I recently had an ill-fitting bike that was just simply garbage to ride for a myriad of reason, mostly related to fit issues. I had tons of seatpost extended, because the seat tube was too short to really let me extend my legs. As such, the saddle was high above the bars, causing me to be hunched over in an uncomfortable position. So I bought some riser bars, which did help a little with the uncomfortable position. They were 2.5" rise if I recall. It made climbing really suck because the front wheel was always trying to lift off the ground. It just wasn't an ideal combination and in the end I was making all these crazy adjustments just to compensate for poor fitment. I sold the bike and got something in a larger size, with a shorter stem, and it's made all the difference in the world. It's so much more comfortable, and I don't have to run a high rise stem or bars, so it climbs better. I have found a little shorter stem to slow down steering and handling in general. That's desirable on a freeride bike or aggressive trail bike in my experience.
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  29. #29
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    Quote Originally Posted by dirtrider7
    Thank you. All the comments about stem length and handling is rubbish. People wanting short stems is rubbish as well....go to a smaller frame.
    I ride a Large 29er hardtail with 130mm stem and the handling and my CG on the bike is perfect. One size does not fit all.
    If you want to ride a big bike with short stem because you want a taller head tube that's fine as well. Stem length as you say is for fit tuning and not to tune handling. Yes fit is about CG on the bike which will affect the weight on the front wheel.
    I agree that there is not a one size fits all and that current trends may not be the best for everyone, were as the right fit is...but like any other seemingly "small" geometry or top tube or chainstay length etc... it does have an effect- some may notice some may not.

    If you leave frame size/fit, bar width, etc.. out of the equation and only change the stem length it will have a direct impact on handling, not complet rubbish. Just as you mention above it affects how much weight is on the front tire- this has a impact on climbing, turning, decending...
    I Just wish I could ride more!


  30. #30
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    Quote Originally Posted by Jim311
    I'll post my experience, since I recently had an ill-fitting bike that was just simply garbage to ride for a myriad of reason, mostly related to fit issues. I had tons of seatpost extended, because the seat tube was too short to really let me extend my legs. As such, the saddle was high above the bars, causing me to be hunched over in an uncomfortable position. So I bought some riser bars, which did help a little with the uncomfortable position. They were 2.5" rise if I recall. It made climbing really suck because the front wheel was always trying to lift off the ground. It just wasn't an ideal combination and in the end I was making all these crazy adjustments just to compensate for poor fitment. I sold the bike and got something in a larger size, with a shorter stem, and it's made all the difference in the world. It's so much more comfortable, and I don't have to run a high rise stem or bars, so it climbs better. I have found a little shorter stem to slow down steering and handling in general. That's desirable on a freeride bike or aggressive trail bike in my experience.
    this is extremely helpful because i have almost the same experience. i'm 5'9" and my prior bike was flat bar road bike. the handlebars were too low due to geometry and too much cutting of steerer tube. my back was hurting so i installed 2" risers. it helped but was still not enough. if you get a chance i'd really appreciate your feedback in my thread (click here) where i'm deciding between a 17.5" and the 19" trek cobia 2011 29er. the handlebars seem kind of low on the 17.5" and i don't want to repeat our previous mistakes.

  31. #31
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    Quote Originally Posted by knottshore
    I agree that there is not a one size fits all and that current trends may not be the best for everyone, were as the right fit is...but like any other seemingly "small" geometry or top tube or chainstay length etc... it does have an effect- some may notice some may not.

    If you leave frame size/fit, bar width, etc.. out of the equation and only change the stem length it will have a direct impact on handling, not complet rubbish. Just as you mention above it affects how much weight is on the front tire- this has a impact on climbing, turning, decending...
    But the wrong thesis. Stem length is about tuning fit and shouldn't be used to tune steering response. Also steering response is affected by how much weight is on the front wheel which typically is tied to a long and not shorter stem. Further the overall geometry of the bike in terms of head tube angle, length of rear stays, amount of trail and even sta affect the handling in aggragate of a bike more than stem length. Riding with a short stem if fit is correct means you are riding a bike with a shorter wheelbase which will likely affect steering more than stem length. It is much more about the geometry of the bike and rider weight fore/aft than stem length which determines how a bike handles.

  32. #32
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    Quote Originally Posted by jbbikerider
    Quote of the day. It's about finding a balance over the bike. Wether it's a 60mm or a 130mm it's about placing the rider in the optimal position.

    I'm glad you read my sig.

  33. #33
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    Regardless of bike size it's the relationship between the handle bar grip position, the bikes BB and the contact patch on the front tyre, weight moves infront of the contact patch and the rear wheel will come up, as simple as.

    Climbing is the relationship between, seat and bars mainly compared to rear tyres contact patch, weight moves behind this and the front comes up.

    Setting the balance to suite your terrain is what counts.


    Also for muddy conditions, more weight over the front wheel is key, but bad for steep rough descents.

  34. #34
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    Quote Originally Posted by dirtrider7
    But the wrong thesis. Stem length is about tuning fit and shouldn't be used to tune steering response. Also steering response is affected by how much weight is on the front wheel which typically is tied to a long and not shorter stem. Further the overall geometry of the bike in terms of head tube angle, length of rear stays, amount of trail and even sta affect the handling in aggragate of a bike more than stem length. Riding with a short stem if fit is correct means you are riding a bike with a shorter wheelbase which will likely affect steering more than stem length. It is much more about the geometry of the bike and rider weight fore/aft than stem length which determines how a bike handles.
    I believe you missed the point. No worries as none of it is on point with the OP's Q anyway.
    I Just wish I could ride more!


  35. #35
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    Stupid

    Come on gang, anyone that thinks 120/130 and riser bars on anything off road is a good idea is stupid. If you need anything longer than 100mm then get the next size up frame. Unless you are 6.5 (me) and there isnt a larger off the shelve frame available then please dont use ridiculous long stems for off road. If you tell me that your 130mm is fine and you have no issues with steering you are dreaming or unaware of the improvements a shorter stem will have to your allround off road riding experience.
    Talk leverage, understeer, weighting, sitting in the bike, size of your stem, width of bar, rise or no rise, steering, etc till the cows come home but every rider, frame, size, terrain and requirement is different but long stems are dumb for off road.
    IMO
    JD

  36. #36
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    Quote Originally Posted by knottshore
    I believe you missed the point. No worries as none of it is on point with the OP's Q anyway.
    Hard to say...you didn't make one...lol.

  37. #37
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    Quote Originally Posted by johnd663
    Come on gang, anyone that thinks 120/130 and riser bars on anything off road is a good idea is stupid. If you need anything longer than 100mm then get the next size up frame. Unless you are 6.5 (me) and there isnt a larger off the shelve frame available then please dont use ridiculous long stems for off road. If you tell me that your 130mm is fine and you have no issues with steering you are dreaming or unaware of the improvements a shorter stem will have to your allround off road riding experience.
    Talk leverage, understeer, weighting, sitting in the bike, size of your stem, width of bar, rise or no rise, steering, etc till the cows come home but every rider, frame, size, terrain and requirement is different but long stems are dumb for off road.
    IMO
    JD
    Sadly the internet is littered with guys like you.
    Armstrong's race bike below that he won Leadville on. Riser bar + 120mm stem and he is 5'10" on a size Large Trek Fuel.
    Get a clue.
    Attached Thumbnails Attached Thumbnails Stem length question - anyone?-lances-mtb-2010-resize.jpg  


  38. #38
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    Armstrong's race bike below that he won Leadville on. Riser bar + 120mm stem and he is 5'10" on a size Large Trek Fuel.
    Yes but he got such a big cardio and power that he could win Leadville with a Beach cruiser. He is also a roadie so his reflex is to keep the same set up on a mountain bike = wrong decision for most average riders with average skills. I used to be a roadie too and he took me few years to figure out that a long stem on a mountain bike doesn't work like it works on a road bike. Shorter stem is the way to go.

  39. #39
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    Stem length is about rider position. Longer puts you a little more forward. That can be a bit of an advantage for climbing and a bit of a disadvantage for decending, but saying that a 120 mm stem doesn't make sense for anyone is just dumb, IMO.
    And come up with all the excuses for Armstrong you want, the bottom line is that he ran a 120 mm stem. I guess he needs to read more from the geniuses here at MTBR.

  40. #40
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    Quote Originally Posted by johnd663
    Come on gang, anyone that thinks 120/130 and riser bars on anything off road is a good idea is stupid. If you need anything longer than 100mm then get the next size up frame. Unless you are 6.5 (me) and there isnt a larger off the shelve frame available then please dont use ridiculous long stems for off road. If you tell me that your 130mm is fine and you have no issues with steering you are dreaming or unaware of the improvements a shorter stem will have to your allround off road riding experience.
    Talk leverage, understeer, weighting, sitting in the bike, size of your stem, width of bar, rise or no rise, steering, etc till the cows come home but every rider, frame, size, terrain and requirement is different but long stems are dumb for off road.
    IMO
    JD
    I would caution about making generalizations such as "if you need longer than 100mm then you need the next size up frame" and "long stems are dumb for off road".

    That is very shortsighted.

  41. #41
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    Well - I've just changed from a 90mm stem to a 70mm stem - and I have to say the difference is dramatic!

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    After reading these posts it would seem that handlebar width is inversely proportional and stem length is directly proportional to the length of a rider's manhood.

  43. #43
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    Quote Originally Posted by dirtrider7
    Hard to say...you didn't make one...lol.
    Point: Stems can affect how a given bike with a given rider handles. This is not necessarily just due to the length but also where it positions the riders weight ectů( "given" in this case indicates a "fixed" or "constant") Hopefully this helps demystify this complicated concept.

    As you rightly point out there are more than just a few variables that come in to play which affect handling, many more so than a stems length, which is why I clearly indicated that you have to leave the other things out of the equation. Having to go in to a complete dissertation of every aspect of how trail, wheel base, HA, CS etc... affect how a bike handles is not necessary as it is inferred if not obvious. You may want to read a few of the earlier posts in the tread for it to make sense.
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  44. #44
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    Quote Originally Posted by misanthrope
    After reading these posts it would seem that handlebar width is inversely proportional and stem length is directly proportional to the length of a rider's manhood.
    I must disagree (after all this seems to be the thing to do on these here forums...) and say that you have it backward- wide bars are directly proportional to one's manhood, and if you have wide bars you must run a short stem, you can not have wide bars and a long stem, or can you? What is fashionable after all?

    ( Please don’t contradict this unless you have concrete evidence to support this FACT or simply a link to another internet site, blog or forum full of facts…)
    Last edited by knottshore; 07-14-2010 at 09:21 AM.
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  45. #45
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    One surprise benefit of a 120mm stem is how flickable the rear end becomes. You can really pull up the back end with ease over step-ups on climbs. The greater weight over the front wheel does help lean-in cornering quite a bit.

    To go with a longer stem and lower bars, your descending skills have got to improve to a point where that's not a problem. The way I have it on my 29er, endos are again possible for me but I mind technique. Training on trails with a cross bike where the bars are even lower has inspired some of these changes.

  46. #46
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    Yes

    Quote Originally Posted by BruceBrown
    I would caution about making generalizations such as "if you need longer than 100mm then you need the next size up frame" and "long stems are dumb for off road".

    That is very shortsighted.
    Yes it was short sighted of me and reeks of generalisation.

    Each to their own setup but please lets not suggest the OP (or anyone new to the sport) that they run a 120/130mm stems...... not the optimum set up............ oh unless you are DR7 or Lance (great example - chill mate). Bike shops should ensure that customers are on the right bike / size frame for their size / weight and intended use. If that use is bike paths and commuting then fine with longer stems. I have had to run long stems for 20 years to fit on regular rigs and now there are more XXL or XL options in production 29ers l have been able to shorten my stem to 90. 90mms or less and wide flat bar is a revelation for me and just might be for others. Alternative bars (Jones BS LG drops) require slightly longer stems due to the excessive sweep. 29ers are often taller up front so keeping it low is often an issue.
    IMO
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    Quote Originally Posted by dirtrider7
    Armstrong's race bike below that he won Leadville on. Riser bar + 120mm stem and he is 5'10" on a size Large Trek Fuel.
    Get a clue.
    Think I've just realised why Lance has been crashing so much recently.

  48. #48
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    Quote Originally Posted by customfab
    stem length is about fine tuning fit not so much about handling. Fit>***
    No, it's also about handling.

    Why do all DH bikes run short stems (<= 50mm)?

    Same for BMX.

  49. #49
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    It does affect handling. The longer the stem, the further over the front wheel axis you are. This can be a problem ......ie. flickability!

  50. #50
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    I bet the OP didn't think this discussion would get so heated!

    My advice would be try the shorter stem. You've got nothing to lose.
    Changing your stem has to be one of the cheapest ways to tune your bikes handling.

    Let us know how it goes.

  51. #51
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    Just sold my 29er frame that fit me with a 90mm stem. Going to reassemble my previous frame that fit well with a 110mm stem because it rode better in every instance. In my case, the slightly smaller of the two bikes handles more nimbly in technical terrain: easier to navigate rock gardens, easier to climb baby-head covered trails. Descending was better too, as the slightly smaller frame allowed me to more dramatically adjust my weight over the bike. As others have mentioned, it is more flickable, but this idea of maneuverability applies to every aspect of the trail, not just while airborne.

    I think for riders that are more static while riding (i.e. somewhat tense, or perhaps just less active over the bike), a shorter stem will make descending easier. I can't help but think that this more-stable-during-descents set up is somewhat of a crutch for riders that fear going OTB. Seems similar to seeking more and more travel to offset a lack of interest &/or ability to ride smoothly over rough terrain. But that's just my opinion, and everyone has one. As long as folks are riding, I could care less how they set their bike up, so long as it doesn't endanger me on the trail. One man's opinion based on a few years in the saddle. Just another opinion to throw into the ring.

    As for Lance: He'll ride the sh!t out of that bike, and can rail a mtb better than most, 120mm stem and all. No such thing as too long a stem; only too long for you. Now hopefully someone will teach him how to change a tube.

  52. #52
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    Good post 105MOP.
    I agree about the shorter stem trend being in part a downhill crutch. Emphasis these days in marketing has been much more downhill oriented, with an average joe trail rider buying 6 inch travel 35 pound bikes. But if your riding style leads you to be more of a downhill guy, then a "weight back" set up makes sense.

    In my case, I'm 5'9", but I've got a torso of a 6'2" guy and the legs of a midget.
    So I need to get a smaller frame so I have stand over and don't have a seatpost jammed all the way down, and need to run a longer stem for cock pit room.

  53. #53
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    Quote Originally Posted by dirtrider7
    But the wrong thesis. Stem length is about tuning fit and shouldn't be used to tune steering response. Also steering response is affected by how much weight is on the front wheel which typically is tied to a long and not shorter stem. Further the overall geometry of the bike in terms of head tube angle, length of rear stays, amount of trail and even sta affect the handling in aggragate of a bike more than stem length. Riding with a short stem if fit is correct means you are riding a bike with a shorter wheelbase which will likely affect steering more than stem length. It is much more about the geometry of the bike and rider weight fore/aft than stem length which determines how a bike handles.

    I have been riding my 20" Jabberwocky for some time now and the best fit for me is a 100mm stem as the 24.5" TT is kinda 'condensed' for my tastes, even with the steeper ST angle and resulting longer front center.

    However, I vasty prefer the handling with a 90mm stem, even though it is not the best fit.

    So, at least in this case, it is not the best fit, but the best handling that the shorter stem gives me, even though we are only talking 10mm here.

    It even surprises me.

    However, it is so convoluted...stem length needs to relate to the rest of the bikes set up, etc and even then a riders preferences have to be figured in.

    All other things being equal, I prefer a longer eff TT, shorter stem and shorter (moderately so) CS length on 29ers.

    But, here we go again...the Epic 29er I ride has a 25.25" TT and a 105mm stem. The best fit is with a 90mm stem and yet I prefer the handling with the 105mm stem which stretches me out a bit.

    Moral to the story???

    Try different lengths and combos till it feels best and then ignore all the threads like this.

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  54. #54
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    Armstrong's bike is set up for X/C racing where the race is won and lost on climbing not descending. At the other end of the spectrum is Greg Minnaar's bike pictured above. It has a very short stem, wide bars and a slack head angle. Just because a pro has their bike set up a certain way doesn't mean it's best for us mortals; I wouldn't want to use Bode Miller's ski and binding set up for example.

    Most of my few comments I've written have been on the merits of shorter stem and wider bars will give you better handling and control especially going downhill.

    I've had both set ups on my current bike, 120mm stem with 26" wide bars ( the way the bike came ) and currently 70mm stem with 30" bars. I do have to adjust my body position on steep climbs but the bike handles way better going downhill. I'm currently building a new bike with a longer top tube, 50mm stem, and 31" bars. I pedal up everything I go down. I also think you need to use the shorter stem in conjunction with the wide bars to get the real benefit.

    I agree that if you need a 120mm stem to "fit" your bike your top tube is probably to short.

    It's all a matter of what you want your bike to do best; I want my bike to have the best control and handling going downhill.

    If you look at the same model bike from say 5 years ago the current model will have a slacker head angle, shorter stem and wider bars. (from what I've seen).

  55. #55
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    Weight further back ie shorter stem is better for going down steep hills and technical stuff.

    Weight forward ie longer stem is better for climbing and also gets more weight on the front wheel which helps for traction in mud.

    I change my setup to suite what I'm riding, I can really tell when I'm riding the wrong setup, or doing stuff I shouldn't be doing in mud mode.

  56. #56
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    Quote Originally Posted by johnd663
    Yes it was short sighted of me and reeks of generalisation.

    Each to their own setup but please lets not suggest the OP (or anyone new to the sport) that they run a 120/130mm stems...... not the optimum set up............ oh unless you are DR7 or Lance (great example - chill mate). Bike shops should ensure that customers are on the right bike / size frame for their size / weight and intended use. If that use is bike paths and commuting then fine with longer stems. I have had to run long stems for 20 years to fit on regular rigs and now there are more XXL or XL options in production 29ers l have been able to shorten my stem to 90. 90mms or less and wide flat bar is a revelation for me and just might be for others. Alternative bars (Jones BS LG drops) require slightly longer stems due to the excessive sweep. 29ers are often taller up front so keeping it low is often an issue.
    IMO
    JD
    Again, any over simplification goes against the grain of bicycle fit. What type of rider and what type of fit are they trying to accomplish? An aggressive, XC race position? An endurance, touring more comfort position? A position between the two (known as the Eddy in road biking named after the fit and position on the bike that Eddy Merckx preferred)?

    Competitive Cyclist does a nice job of explaining the 3 fits (link to the article from their fit calculator page):

    When we look at the bikes we sell we recognize that most of them descend from the traditions of road racing and long distance riding. There are also bikes for time trialing, cyclocross, and other cycling "disciplines" and each of these has its own traditions and optimal fit options. Very few of us actually race and many of us don't ride as long as we might like, but the bikes we sell can all be fit to suit your preferred riding.

    We see three basic styles of road riding fit, each designed to meet clear goals and expectations. We believe that a bicycle that fits your riding style is the one that creates the best experience. We need first to determine what style of fit (or combination of styles) matches you best before we go about achieving a precise, personal fit for you.

    The three styles of fit work with the sometimes complementary and sometimes competing objectives of comfort, speed, efficiency, and power. Creating a great fit involves creating priorities among these objectives and knowing yourself. All bikes should fit comfortably, but this priority can be weighed against other objectives. Every choice we make about fit and the bike we choose (frame, fork, model, material, size, parts, etc.) has consequences for our cycling experience. We can explain either by e-mail or telephone how different choices will change your experience and what the advantages and relative compromises will likely be.

    For example, the more aerodynamic and "aggressive" Competitive Fit emphasizes speed and efficiency but favors those who can adjust to positions that others will find difficult to maintain over long days in the saddle. In other words, the Competitive Fit may for some become uncomfortable over longer distances or it may not suit those for whom the priority of greater comfort actually increases speed. The slightly more relaxed Eddy Fit adds comfort but compromises some aerodynamic and power efficiency in order to gain endurance and ease. The exceptionally comfortable French Fit understands speed as a feature of comfort and puts power and efficiency in terms of longer endurance goals.

    Each of the three styles of fit can be achieved on the same model bicycle, though perhaps not the same size or parts set up. Knowing how you want to ride will help determine what you want to ride.

    1. The Competitive Fit.

    It's called the Competitive Fit because it's our signature fit. We've found that this is the look and the feel that most of our customers expect out of their new bike. This is the most "aggressive" fit and suits those with an interest in racing, fast club riding, as well as those with a greater measure of body flexibility to work within the racer's comfort zones. Most modern road bikes, like the majority we offer at Competitive Cyclist, are usually pictured in sales catalogues with the Competitive Fit. But this doesn't mean that you should ride a bike that looks or fits like this.

    Wanna look like a pro? This is the fit. It features a low, aerodynamic bar position that places slightly more weight on the hands than on the pedals and saddle, a close knee to pedal spindle ratio that emphasizes power and efficiency, and it puts the rider low in the handlebar drops. Typically the frame chosen will be the smallest that is appropriate. In fact, since the heyday of mountain bikes in the 1990s and more recent studies of professionals looking for an aerodynamic advantage, the Competitive Fit has become most bike shop's conventional wisdom.

    After all, who doesn't want to look and ride like a pro? This fit is easy to sell but may not work for you since it actually best suits those who are willing to accept its clear emphasis on speed over comfort. For most of us, the pure Competitive Fit is too extreme even if it is still viable for young riders and racers, for those who love shorter, faster rides, and for those who just find this comfortable. Expect to be rather low even on the tops of the bars where you will spend the majority of your cruising time on the brake hoods, expect too to be lifting your neck slightly to see ahead of you with a rather "short and deep" reach into the bars as you push back on the saddle to stretch out.

    The Competitive Fit creates a more compact body position with the chest low and the back as flat as is necessary to get down into the drops. The saddle to handlebar drop is sometimes as much 10cm or more.

    2. The Eddy Fit.

    Lots of folks find the Competitive Fit to be ideal. But for those who find its aerodynamic emphasis to be overly aggressive and uncomfortable, the Eddy Fit is almost certain to be ideal for you. It's a position that reminds us of the way Eddy Merckx looked on his bike in the early 1970s, and it dates from well before Eddy's time and continued in the pro peloton well into the 1980s.

    There is nothing "dated" about this style of riding. We all know that Eddy, Bernard, and Guiseppe were all very, very fast riders! Bike design has not, in fact, changed that radically since their time---only the look, the fashion, and the style of riding. The Eddy Fit is simply no longer the "fashion" among pros who keep pressing the envelope of comfort to create more efficiency and power.

    The Eddy Fit emphasizes less saddle to bar drop. You will notice less exposed seat post on traditional frames and a lower saddle to bar ratio on all fits, including compact designs. Typically it requires a size up of about 2-3cm in frame size from what is today usually offered by in current aero professional look of today. But make no mistake about it, this fit will get you down the road with speed, efficiency, and power.

    A few differences from the Competitive Fit in addition to a taller front end and less saddle/bar drop is a less craned neck and easier forward-looking position, slightly less weight on the hands and more on the saddle and pedals, and a knee position that usually moves a bit behind the spindle (rather than a knee-over-the-spindle position, thus adding a bit of power). Bikes set up for the Eddy Fit change their look only subtly in comparison to the Competitive Fit though the results are dramatic in terms of greater comfort. This fit is easier on the neck and shoulders but no less suited for racing or fast solo or club riding.

    We adjust this fit by "sizing up" the frame and adjusting the stem lengths to create proper balance, proportion, and to maximize the frame's potential. This position lets you into the drops with less stress on the neck and back and so encourages you to go low into the bars for longer periods. The Eddy Fit typically features a saddle/bar drop of only a few centimeters.

    3. The French Fit.

    This fit is so named because of its legacy in the traditions of endurance road riding such as brevet rides and randonneuring. However, the French Fit isn't merely about touring, riding long, or even sitting more upright. It is about getting the most out of a bike that fits larger and provides much more comfort to the neck, back, and saddle position.

    While the Competitive Fit generally puts you on the smallest appropriate frame and the Eddy Fit sizes up a bit or raises the bars, the French Fit puts you on the largest appropriate frame. While this bucks some current conventional wisdom - and is, in fact, the least commonly used position of the three we espouse - it is still the position advocated by some of cycling's wisest and most experienced designers, who also happened to be riders who like to go fast and far with an ideal amount of comfort.

    This fit features a taller front end (with a larger frame and/or head tube extension and stem), handlebar to saddle drops that are much closer to level, and favors riders who are looking to ease stress on the neck and back, ride as long and as far as they like, and are not concerned with the looking like an aggressive professional. In comparison to the Eddy Fit, the rider has even more weight rearward and a slightly more upright position such that "hands in the drops position" is close to the Competitive Fit's "hands on the hoods position." Some may say that this was not how modern race bikes were "meant" to fit but we have learned that the French Fit's size up tradition works great on the most modern bikes.

    By increasing the frame size we raise the bars without radical riser stems and still create balance and proportion with respect to the important knee-to-pedal dynamic. It is important to remember that as frames get larger the top tube effectively shortens. This means that the longer top tube on a larger frame is appropriate because as the bars come "up" and the ratio of saddle to bar drop lessens, the rider achieves a "reach" from the saddle to the handlebars that is just right!

    We recommend this fit for riders who really want to be comfortable and fast over longer distances. Please note that the French Fit disregards all emphasis on stand over height (standing with the bike between your legs and your shoes flat on the ground) because the French Fit school believes that this measurement has little actual value regarding fit. An ideal compromise for those who can't shed their concern regarding stand over height is the choice of a "sized up" compact design to achieve a higher relative handlebar position.

    Nevertheless, a French Fit can work with traditional, non-sloping frames as well. As an example, a person who might ride a 55cm or 56cm frame to achieve the Competitive Fit, might ride as much as a 59cm or 60cm in the French Fit. While bikes in the French Fit are not the racer's fashion they tend to look elegant, well proportioned, and ride like a dream.

    ----------


    Sheldon Brown
    speaks about fit and has links to excellent articles about fit as well.

    It's easy to see that, based on which type of "fit" a rider prefers for their riding, that frame sizing and stem length will not be the same. A "competitive fit" in a more aggressive position will have the rider on the smallest frame possible which will have a longer stem than a rider on the Eddy fit or the French fit with the more upright and larger frame size.

    I am in the French Fit category for my road bike with the top of my bars even with my saddle. I've ridden in this position for years not even knowing it was called the "French Fit", but just based on preference. I ride in the hoods 90% of the time on an XL 58cm Specialized frame using a high rise stem that is very short. I can ride for hours in this position with no neck, hand or wrist pain which is my preference. This set up has my hoods being exactly in the same reach position as my flat bars on the mountain bikes in terms of distance from the saddle. And on my XL mountain bike frames, I have stems of 90mm on my JET (flat bar with 5 degree sweep), 120mm on my Dos Niner (flat bar with 8 degree sweep) and 110mm on my RIP 9 (flat bar with 12 degree sweep).

    Type of bike fit (aggressive, Eddy or French - or whatever you want to call them for a road bike and a mountain bike), one's handlebar choice, and each rider's preference all factor into the equation which demonstrates stem lengths can be all over the map - and be the "right" choice for the intended fit/application.

    BB

  57. #57
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    Quote Originally Posted by Jeff in Bend
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    Armstrong's bike is set up for X/C racing where the race is won and lost on climbing not descending. At the other end of the spectrum is Greg Minnaar's bike pictured above. It has a very short stem, wide bars and a slack head angle. Just because a pro has their bike set up a certain way doesn't mean it's best for us mortals; I wouldn't want to use Bode Miller's ski and binding set up for example.

    Most of my few comments I've written have been on the merits of shorter stem and wider bars will give you better handling and control especially going downhill.

    I've had both set ups on my current bike, 120mm stem with 26" wide bars ( the way the bike came ) and currently 70mm stem with 30" bars. I do have to adjust my body position on steep climbs but the bike handles way better going downhill. I'm currently building a new bike with a longer top tube, 50mm stem, and 31" bars. I pedal up everything I go down. I also think you need to use the shorter stem in conjunction with the wide bars to get the real benefit.

    I agree that if you need a 120mm stem to "fit" your bike your top tube is probably to short.

    It's all a matter of what you want your bike to do best; I want my bike to have the best control and handling going downhill.

    If you look at the same model bike from say 5 years ago the current model will have a slacker head angle, shorter stem and wider bars. (from what I've seen).
    Tell that to Lance Armstrong. What at 5'10" Lance is going to ride a Fuel XL? This whole discussion is ridiculous. There is absolutely no right or wrong. What is hilarious about all those that draw a line in the sand as to what is acceptable is...take two 6'ers...one with 35inch sleeve length like me and another with a 32 inch sleeve which is common. Lance not only has long legs but very long arms as well which is the statistical norm for long legged people. Place two 6'ers on the same Large 29er with two different arm lengths and by dialing in stem length...long stem for long armed rider, the same fore/aft rider CG is achieved as a short stem is for a short armed rider. Lance can ride whatever bike he wants and tests extensively. Sta even matters for stem length because it changes effective top tube length and rider fore/aft weight distribution. There is NO universal correct stem length for any given bicycle.
    I asked Sheldon Brown the exact same question before he passed away and he said the full range is acceptable...depends on the rider and how the rider likes to ride.

  58. #58
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    Quote Originally Posted by dirtrider7
    Tell that to Lance Armstrong. What at 5'10" Lance is going to ride a Fuel XL? This whole discussion is ridiculous. There is absolutely no right or wrong. What is hilarious about all those that draw a line in the sand as to what is acceptable is...take two 6'ers...one with 35inch sleeve length like me and another with a 32 inch sleeve which is common. Lance not only has long legs but very long arms as well which is the statistical norm for long legged people. Place two 6'ers on the same Large 29er with two different arm lengths and by dialing in stem length...long stem for long armed rider, the same fore/aft rider CG is achieved as a short stem is for a short armed rider. Lance can ride whatever bike he wants and tests extensively. Sta even matters for stem length because it changes effective top tube length and rider fore/aft weight distribution. There is NO universal correct stem length for any given bicycle.
    I asked Sheldon Brown the exact same question before he passed away and he said the full range is acceptable...depends on the rider and how the rider likes to ride.
    You misunderstood what I ment, I said if you need a 120mm stem to "fit" your bike it's probably to small. He's got a 120mm stem on to be stretched out for max climbing power not because it's that length for bike fit IMO.

    Stem length is more important to bike handling than to bike fit IMO. If you went to a pro x/c or road race I bet all the stems would be on the long side amongst all size of riders. If you went to a pro downhill race I bet all the stems would be on the short side amongst all size riders.

    I never said a longer stem wasn't acceptable or drew any line in the sand, it just changes the way your bike will perform. Like I said before it's about what you want your bike to do best.

  59. #59
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    Quote Originally Posted by xcbarny
    My advice would be try the shorter stem. You've got nothing to lose.
    Shorter stem, sure but how much shorter? Longer bars are no problem - I can buy 680mm bars and always cut them down to 670mm or 660mm if that feels better. At $30-60 each for stems though, it would cost a lot to try out 110mm, 100mm and 90mm versions to see which feels best.

    Well, maybe not. If I just accept that there will be return shipping ($12 for UPS), I could order all three sizes, try them all, and then return the one's I don't want. It's probably worth $12 just to know I'm on the right stem instead of guessing once and living with it.
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  60. #60
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    Quote Originally Posted by Clones123
    Shorter stem, sure but how much shorter? Longer bars are no problem - I can buy 680mm bars and always cut them down to 670mm or 660mm if that feels better. At $30-60 each for stems though, it would cost a lot to try out 110mm, 100mm and 90mm versions to see which feels best.

    Well, maybe not. If I just accept that there will be return shipping ($12 for UPS), I could order all three sizes, try them all, and then return the one's I don't want. It's probably worth $12 just to know I'm on the right stem instead of guessing once and living with it.
    Go to your LBS. They'll let you borrow a bunch of stems from their used goodies box (or sell them all to you new allowing you to bring back the ones that don't work for a refund). Or you can sit there in the shop and swap out to your heart's content until you find the magic wand. Or use one of those adjustable Salsa stem doohickeythingamabobs that dial in stem fit at the LBS (many of them have one).

    BB

  61. #61
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    90mm vs 100mm vs 110mm vs 120mm

    Well the LBS had a bunch of stems but most were 26mm (road) stems and also over-priced. The few stems they had that might have worked were either 17 or 35-degree rise which is definitely not what I was looking for. So here is what I ordered...



    I started off with the 90mm stem and, combined with the wider bar, the steering was significantly lighter and faster than the stock 620mm bar on a 120mm stem. I wasn't actually thrilled with the change which seemed too light and fast though maybe I'd get used to it. Then I tried the 110mm stem; not much of a difference length-wise from my 120mm starting point but combined with the wider bars it seemed like a good feel and an improvement over stock. I didn't even try the 100mm stem just because the Truvativ AKA stem is significantly heavier than the Stylo Race stems and it was more expensive too. A 100mm Truvativ Stylo Race stem would have been tempting - sort of striking a middle ground - but BlueSky didn't have any in that size which is why I ordered the AKA.
    Last edited by Clones123; 07-23-2010 at 09:55 PM.
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  62. #62
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    stem length

    I am new to mountain biking so I was looking up info on this site about how stem length effects your riding. From what I gather from reading the stem length is primarily to help you find the right CG on your bike.

    I am also a physical therapist and a bio-mechanist so I was thinking that a longer stem would create more torque on the wheel (like a wrench would on a nut). So if one is strong and tends to overreact to situations, due to fast reflexes and strong muscles, one could easily create too large of a torque, a fast wheel change, and tend to be more out of control with the wheel. If you have good reflexes and motor control then a larger stem would be beneficial due to the power/torque you could produce in difficult situations and still maintain control.

    If you have not so good reflexes and are weaker, then a smaller stem could be easier to control. This would be due to less torque produced and therefor decreased speed of wheel position change, and decreased distance the wheel would change when you react to what ever situation. This should give you a better since of control but less power going uphill and maneuvering around/through rocks. But a wider handlebar will help make up for that loss of power.

    So I can see why some people like longer stems and some short stems with wider bars. Its likely due to your reaction time, motor control, and overall strength. And we all very in those aspects. So It looks like we just need to find out through trial and error.

    I think that makes sence in my mind. I don't know that I am right though.

  63. #63
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    @ Clones123: So have you settled on setup yet?

    I was also wodering about adding in a setback seatpost into the equation? Ive seen up to 25mm setback which would offset reducing the stem by the same amount. Of course this would move CG rearward.

  64. #64
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    From good old bike radar

    Huge generalization here.. but..

    Short stem = quicker steering but can be twitchy, better for decending.
    Long stem = slower steering but more stable, better for climbing.

    Thin bars = quicker steering but more twitchy, easier climbing + less control on descents.
    Wide bars = slower steering but more stable, harder cliimbing + more control on descents.

    So I've opted for a short stem with wide bars...
    The twitchyness of the short stem is counteracted by the stability of the wider bar. Giving better decending at the expense of harder climbing.

    Long stem + thin bars..
    Slower but stable steering is counteracted by the quicker steering of thin bars.
    Giving more economical climbing at the expense of less controll descending.

    Short Stem + Thin Bars...
    Very twitchy.

    Long Stem Wide Bars...
    Super slow steering.

    So...
    For XC the longer stem/thin bars is beneficial because it helps with climbing.
    DH/FR/AM a shorter stem + wide bars offer downhill stability and better riding position.

  65. #65
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    For every action there is a equal and opposite reaction, this is true with Stem length also, they cancel each other out so there really is no effect left.

    So use Stem length to set your CG mainly as going down hill un seated the seat position becomes irrelevant, then tweak your seat position to get the right length.

    Unless your a XC Race which doesn't do anything technical, then seat position for max power is key and a long reach / stem is likely what your after.

  66. #66
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    Quote Originally Posted by Koppuh Klyde
    @ Clones123: So have you settled on setup yet?

    I was also wondering about adding in a setback seatpost into the equation? Ive seen up to 25mm setback which would offset reducing the stem by the same amount. Of course this would move CG rearward.
    Yup - 110mm stem with the 680mm bar. In truth I probably could have just gone to the wider bar alone on the stock 120mm stem but I wasn't keen to stick with a skinny 25.4mm handlebar - seemed a little too department store.

    I've only seen a few seat posts where the seat mount is right on top of the post. Mine is the more common variety with the mount behind the seat post. With the saddle as far back as allowed, I'm at the handling limit for climbing seated. Something like a Thompson angled seat post in my case would take too much weight off the front wheel plus have me standing for every climb.

    Everything is a compromise but I'm happy with the level of optimization I have now. Thanks to everyone for the feedback and insights.
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  67. #67
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    My experience, FWIW.

    I'm 6'-3", been riding a 120mm stem on my mountain bike.

    This weekend I put on a 70mm, based on advice from MTBR.

    It felt really, really odd at first. (It was almost 2" shorter.) The climbing definitely took a bit of getting used to. I still cleaned the same stuff as always. The super slow grind around ruts and rocks was more difficult at first. By the end of the ride it felt natural.

    Going down... SO much better. Much less of the 'about to endo' feeling on steep turns that always give me the willies before. Super-fast straight descents felt good too.

    So, yeah, I'm a believer.
    Last edited by schnee; 08-03-2010 at 10:22 PM.

  68. #68
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    Quote Originally Posted by Clones123
    I'm riding a size-Large hardtail XC 29er with a 120mm stem and a 620mm (24.4in) wide, 25mm rise handlebar. I recently demoed a full-squish 26er with a shorter stem and 690mm bar and really liked the quicker steering.

    I'm just guessing here but am I correct that a 100mm stem would quicken the steering on my bike? Any downsides?

    My thinking is that with a 100mm stem and bar about 670mm wide (plus or minus 10mm), I'd have better and faster control of the front end. I've read some magazine testers complaining about the narrow bars common on budget bikes. Seems to me that 620mm is on the narrow side for optimum control (though 690mm seemed like a tight squeeze between the trees! LOL.). TIA.
    I'm also on an Access 29er...mine is 2010 9.7 size Large (21") and it came with 120mm stem and MTB, butted aluminum, 710mm, 25mm rise bars which felt good at first but then found that I was too stretched out. Measured my other bike cockpit and set this one up accordingly. Measured from same part of saddle rails to the center cap screw and from saddle rails to center of bars. Swapped out to a 90mm stem while I was installing Cane Creek ZS-3 headset and it felt great during parking lot test ride. We'll see how it is offroad. Will prolly swap out stock bars for my favortie Easton EA50 riser bars:

    http://www.eastoncycling.com/mountai...rs/ea50-mb-280

    Easton's site used to list the available rises???

    Maybe I shoulda bought the Medium (19") frame that comes with 110mm stem as this would have been very close to the cockpit measurements that I came up with from my other bike, but the 19" felt kinda small during my pre-purchase test ride. Ah guess the frame is cheap enough that I can buy and swap all my parts anytime...lol!
    Get off the couch and ride! :)

  69. #69
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    50mm stem and 31" wide bars.

    Stem length question - anyone?-dsc01276-1408-x-1056-.jpg

    Stem length question - anyone?-dsc01278-1408-x-1056-.jpg

  70. #70
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    Quote Originally Posted by Jeff in Bend
    50mm stem and 31" wide bars.
    Whoa - that looks like a handful. Is it just me or is that a seriously steep head angle?

    Really nice pedals by the way.
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  71. #71
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    Quote Originally Posted by Clones123
    Whoa - that looks like a handful. Is it just me or is that a seriously steep head angle?

    Really nice pedals by the way.
    I'm 6'4" and have a 80" finger tip to finger tip wing span. The bike bombs going down hill and I have no problem climbing.

    The head angle is designed at 69 deg with a 521mm A to C fork, I think my fork is 540mm and with the 2.4 tire the angle is probably around 68.5-68. I'll have to measure it.

    The pedals as of now suck, they look good but the pins on the outside of the pedal are the same height as the spindle. I was able to stand on the pedals and turn my foot fairly easily with 5-10s on. I e-mailed Chris @ Canfield to ask if they have longer pins. Unitl then I have installed my existing pedals which grip awesome.

    Edit: 68.5 deg. head angle.
    Last edited by Jeff in Bend; 08-02-2010 at 06:48 PM.

  72. #72
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    Just to add another data point, Gene Hamilton over at better ride claims a shorter stem (50 - 80 mm) and wider bars (27" - 30") = better climbing.

  73. #73
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    Might be better from a chest breathing kind of way, but it'll be harder to keep the front end down with a shorter stem.

    Another DIY 69er I think, cool, build up a 26" wheel RQ2.4 on mine, tightens the angles moving the weight forward which makes for a much better mud eater when required, by simply changing the wheel, and realigning the disk.

  74. #74
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    Quote Originally Posted by track5200
    Just to add another data point, Gene Hamilton over at better ride claims a shorter stem (50 - 80 mm) and wider bars (27" - 30") = better climbing.
    I've taken camps from Gene and now coach for him locally. I recommend everyone interested read the above blog it's good info to think about. In my experience it has been great for me.

  75. #75
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    Quote Originally Posted by Turveyd
    Might be better from a chest breathing kind of way, but it'll be harder to keep the front end down with a shorter stem.
    It's really only an issue ( for me anyway) on steep small ring climbs; just compensate with body position by lowering your chest and or sliding forward on the saddle.

  76. #76
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    I took advice from Gene Hamilton and went down from a 110 to a 90, now I'm settled with a 60mm. I'm climbing and descending better than ever, and going over the 'bars (something I was doing all too regularly!) never!
    It did feel weird at first, but I gave it time - and I'll never go back!!

  77. #77
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    Coming a little late to the thread, but as far as the Lance thing goes, Leadville doesn't have much singletrack or technical riding, does it? It makes sense that a roadie would want a more stretched out position for this sort of race. Perhaps he would use a shorter stem if it was the BC bike race.

  78. #78
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    went from a 100mm to 75mm today but haven't tested it out yet but I have a flat bar that's only 23" which is a bit too small probably. will eventually get wider flat bar which is my preference.

  79. #79
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    I agree with this...

    Quote Originally Posted by 105millimetersofpleasure
    Just sold my 29er frame that fit me with a 90mm stem. Going to reassemble my previous frame that fit well with a 110mm stem because it rode better in every instance. In my case, the slightly smaller of the two bikes handles more nimbly in technical terrain: easier to navigate rock gardens, easier to climb baby-head covered trails. Descending was better too, as the slightly smaller frame allowed me to more dramatically adjust my weight over the bike. As others have mentioned, it is more flickable, but this idea of maneuverability applies to every aspect of the trail, not just while airborne.

    I think for riders that are more static while riding (i.e. somewhat tense, or perhaps just less active over the bike), a shorter stem will make descending easier. I can't help but think that this more-stable-during-descents set up is somewhat of a crutch for riders that fear going OTB. Seems similar to seeking more and more travel to offset a lack of interest &/or ability to ride smoothly over rough terrain. But that's just my opinion, and everyone has one. As long as folks are riding, I could care less how they set their bike up, so long as it doesn't endanger me on the trail. One man's opinion based on a few years in the saddle. Just another opinion to throw into the ring.

    As for Lance: He'll ride the ***** out of that bike, and can rail a mtb better than most, 120mm stem and all. No such thing as too long a stem; only too long for you. Now hopefully someone will teach him how to change a tube.
    100%. Mirrors my experiences exactly. I run a 120mm stem on one bike and 100mm on another. No problems going over the bars on either.
    However, I think this comment that was made earlier is just wrong.
    " Riding with a short stem if fit is correct means you are riding a bike with a shorter wheelbase which will likely affect steering more than stem length".
    What does stem length have to do with wheelbase?. I really don't understand this at all.
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