1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    questions about stem selection

    I want to upgrade to a shorter stem. How much twitchier will a 70mm stem be over a 110 stock stem? Can someone elaborate on angles too? Is it better to have an upward angle or straight? I am looking for a more responsive steering and to shift my weight rearward a tad.

  2. #2
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    a shorter stem will reduce the radius of the handle bar travel, by 30mm it really won't be too noticeable at normal speed, however at low/ tight corners might give you better control, at fast/ down hill might be too responsive. Depending on ur type of riding u might have to try a couple, stem too long might over work ur back, too short your arms and shoulder will suffer, u need to aim for a good overall balance. trying to fix bike handling gravitates more towards the bikes geometry. Stem angle is used for comfort and weight distribution, a high up degree angle makes u more upright taking some weight of the front tire, lower the degree of the stem will give more drop on the upper body and more weight on the front tire. if ur on the experimenting stage get a cheap adjustable stem to try different setups then when ur happy with it get the one u want, 1cm might not affect handling but it might be spot on for comfort.

  3. #3
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    Angle should be to put the bars at the height that you want your hands. Flatter tends to be more toward cross country/racing. There isn't a way to tell how much twitchier it would be ,the only way for you to know is to try it. With a shorter stem,people go with wider bars.That makes the reach about the same.

  4. #4
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    Quote Originally Posted by joel787 View Post
    a shorter stem will reduce the radius of the handle bar travel, by 30mm it really won't be too noticeable at normal speed, however at low/ tight corners might give you better control, at fast/ down hill might be too responsive. Depending on ur type of riding u might have to try a couple, stem too long might over work ur back, too short your arms and shoulder will suffer, u need to aim for a good overall balance. trying to fix bike handling gravitates more towards the bikes geometry. Stem angle is used for comfort and weight distribution, a high up degree angle makes u more upright taking some weight of the front tire, lower the degree of the stem will give more drop on the upper body and more weight on the front tire. if ur on the experimenting stage get a cheap adjustable stem to try different setups then when ur happy with it get the one u want, 1cm might not affect handling but it might be spot on for comfort.
    I am more of a trail rider. I do dream of doing some crazy stuff like downhill and jumps ect but with the type of riding I have available around me plus my skill level it is mainly riding through timber with some tight turns and rocks and tree roots. I am not sure I need a shorter stem but I am looking for basic upgrades to me entry level jamis that doesn't break the bank. I thought from what I had read a shorter stem would benefit me. Now you got me thinking. I already upgraded to better pedals. Looking for my next performance increase.

  5. #5
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    Quote Originally Posted by iowamtb View Post
    I am more of a trail rider. I do dream of doing some crazy stuff like downhill and jumps ect but with the type of riding I have available around me plus my skill level it is mainly riding through timber with some tight turns and rocks and tree roots. I am not sure I need a shorter stem but I am looking for basic upgrades to me entry level jamis that doesn't break the bank. I thought from what I had read a shorter stem would benefit me. Now you got me thinking. I already upgraded to better pedals. Looking for my next performance increase.
    The shorter stem will give you way more confidence going downhill....but you need to run it with wider bars if you don't already have them. Shorter stem and wider bars is the best upgrade you can make to improve handling IMO....there is a ton to read on the topic.

  6. #6
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    Quote Originally Posted by Haymarket View Post
    The shorter stem will give you way more confidence going downhill....but you need to run it with wider bars if you don't already have them. Shorter stem and wider bars is the best upgrade you can make to improve handling IMO....there is a ton to read on the topic.
    Is there a rule of thumb for handlebar width and stem length? I am interested in this upgrade. My jamis has a 620 mm handlebar length and either a 100-110 mm stem length now. How much should I increase handlebar length as I decrease stem length?

  7. #7
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    i don't think stems are really "performance", unless u want stability (short stem/ wide bars) or more responsiveness (short bar/ more drop). everything is a trade off, theres ways to change a bikes geometry, like angled head sets, longer forks. But if u don't know what u want it can be an expensive trial and error, it might work or it might be crap. demo as many bikes as u can, then when u look at a geo table u know what to look for and compare, to develop a sense of bike feeling. major difference now to ur bike would be a decent fork, or rims. But then again it might not be worth the money if at the end u still want a new bike.

  8. #8
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    I just bought this bike 2 months ago lol.

  9. #9
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    ride it, get the stem see if u like it, if u ride a lot of up and down check a dropper seat post too, they have some cheap ones on ebay

  10. #10
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    Quote Originally Posted by iowamtb View Post
    Is there a rule of thumb for handlebar width and stem length? I am interested in this upgrade. My jamis has a 620 mm handlebar length and either a 100-110 mm stem length now. How much should I increase handlebar length as I decrease stem length?
    BetterRide Mountain Bike Skills Tips

    50mm stems - improve handling or too short? | Bike Magic

  11. #11
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    The 70mm stem will feel hugely different to your current setup. Do it, unless your frame is too small for you in the first place. Along with the wider bars, 620mm is way too narrow. 720mm is good for narrow shouldered riders, up to 780 if you're big. I ride 750s and they're ideal for me.

  12. #12
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    I ended up ordering race face 725 mm handlebar set up and a race face 70 mm stem. I cannot wait to get them and put them on!!

  13. #13
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    Quote Originally Posted by AgrAde View Post
    Along with the wider bars, 620mm is way too narrow... for me.
    And 620mm is way too wide for me.
    Bar width, like pedal choice, and saddle choice are highly subjective.
    I'd never ride with my hands more than sholder width apart.
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    Yep, it's subjective and you're an XC rider - not meaning that all in offence. OP says that he's more of a trail rider, with aspirations of getting off the ground and riding some DH tracks. Seems he has different goals, and different requirements from his bike than the average XC rider. He's expressed concerns about stability, and wants to get a less nervous feeling front end.

    I've never met anyone who hasn't felt more confident after making the shift to wider bars, after looking for the results that OP is trying to attain. I don't know any "trail" riders that get in the air and ride DH tracks that feel they benefit from bars narrower than 680, including quite small women. Most small guys I know still like at least 720mm.

    I have for XC, that's fine, but it's not really what this thread is about.

  15. #15
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    I moved to wider bars and a shorter stem a few seasons ago and can't complain. It was time to get with the times lol

    Sent from my 831C using Tapatalk

  16. #16
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    Bike geometry?
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  17. #17
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    Bike geometry? Who you asking?

  18. #18
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    69/440mm? That's what I have anyways

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  19. #19
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    Quote Originally Posted by iowamtb View Post
    Bike geometry? Who you asking?
    I'm asking you since you are the OP. The geometry of the bike makes a huge difference.
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  20. #20
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    I have the 19" frame.


    SIZE 15" 17" 19" 21"
    CENTER of BB to TOP of TT 13.15/334 15.08/383 16.69/424 18.66/474
    ST ANGLE 72.5 72.5 72.5 72.5
    HEADTUBE 3.94/100 4.33/110 5.12/130 5.51/140
    HT ANGLE 70 70 70 70
    EFFECTIVE TT LENGTH 22.00/559 23.03/585 23.82/605 24.61/625
    FORK RAKE 1.65/42 1.65/42 1.65/42 1.65/42
    BB HEIGHT 12.12/308 12.12/308 12.12/308 12.12/308
    CHAINSTAY 17.12/435 17.12/435 17.12/435 17.12/435
    WHEELBASE 41.25/1048 42.32/1075 43.11/1095 43.94/1116
    STANDOVER 28.70/729 30.16/766 31.24/796 32.64/829

  21. #21
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    Definitely XC geometry. Wide bars/short stem does not an AM bike make. I have tried this with several XC geo bikes, and each time the steering sucked. Standing up, my hands felt too far behind the front axle. This gave me the feeling of going OTB. I wasn't able to push my weight into the bars when riding over objects that tend to slow the bike down.

    Keep in mind, an XC bike in stock config (4 inch travel or less) will have a lower front end than a trail/AM bike in stock config (5 inch travel or more).

    questions about stem selection-102910saddlebars.jpg
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  22. #22
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    That picture is very helpful actually. I just built an am bike and coming from an xc I was wondering why I didn't like the steering too much.

    Sent from my 831C using Tapatalk

  23. #23
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    It's kinda hard to see in the pic but notice the silhouette of the DH/AM bikes top tube is higher and the head tube closer than the XC/Race bikes? To get your bars in the same place on an XC bike, you'll need a buttload of spacers, steep stem angle, or high rise bars. I think the wide bars on the slack bikes help get your weight back down to where it would normally be on an XC bike. The short stem puts your butt back where it is supposed to be since the wide bars draw the body forward.
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  24. #24
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    Well I feel like an idiot. I cancelled my orders for my new stem and bars. I was worried about what dgw2jr said so I called and talked to Jamis themselves and they said for sure that would not be a good combo for this geometry. My trouble is the LBS I bought this bike from is helpful for selling and repairing bikes but when it comes to questions about upgrades and improving your ride they don't seem to helpful. As much as I like my LBS I wish I could get better service when it comes to MTBing questions. I hate pestering the companies who produce these products to get answers to my questions. I should be able to talk to my LBS whom I just spent $550 bucks with 2 months ago and then brought a friend in later who also bought a new bike. I feel alone in the cornfield lol.

  25. #25
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    I am from Iowa so I feel your pain. Midwest LBS cater more to those of the roadie persuasion. They sell mountain bikes but the actual sport is well off their radar.

    If you still feel the need for a little more room in the cockpit, try a more subtle change like a 660mm bar and 90mm stem. FWIW, I use a 90mm stem and 680mm bar on a bike with a 71 head tube angle but I live in Utah now and my average rides have about 1000-2000 feet of elevation gain and loss. Contrast to the 150 feet elevation gain I would get back in Iowa. Even with all the descending I'm doing now, I don't feel the need for an AM/Trail bike as I'm already hitting 30mph on some downhills and I really don't want to give up the climbing efficiency of my XC bike.
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