Advertise on Bikeforums.net



User Tag List

Results 1 to 17 of 17

Thread: Stem Length

  1. #1
    Senior Member
    Join Date
    Mar 2005
    Posts
    420
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    How do you judge what is the correct stem length for you? I'm thinking about going from 80mm to 110mm.

    Is that too much? My bike is only a size 48 but the stem is really way too short.

    Thinking about getting this:
    http://www.performancebike.com/shop/...tegory_ID=5235
    To replace my stock Cannondale R700 stem.

  2. #2
    Senior Member
    Join Date
    Feb 2001
    Location
    England
    Posts
    12,195
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    A 48 frame is quite small and should use a proportionally sized stem. If the bike is too small for you, then you should consider a longer frame. The disadvanatge of using a long stem is that the steering will be less sensitive, but the only way to see if this is acceptable is to try it.
    There is no "correct" length for a bike, you set the height and reach of the bars according to your body proportions AND your desired riding position/style. The same rider will use a very different bar position for time trialling, mountain climbing and long distance touring.
    When chosing a new stem, get the correct diameter for both steerer and handlebars.

  3. #3
    Senior Member
    Join Date
    Mar 2005
    Posts
    420
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by MichaelW
    A 48 frame is quite small and should use a proportionally sized stem. If the bike is too small for you, then you should consider a longer frame. The disadvanatge of using a long stem is that the steering will be less sensitive, but the only way to see if this is acceptable is to try it.
    There is no "correct" length for a bike, you set the height and reach of the bars according to your body proportions AND your desired riding position/style. The same rider will use a very different bar position for time trialling, mountain climbing and long distance touring.
    When chosing a new stem, get the correct diameter for both steerer and handlebars.
    If the frame is any longer (taller I should say), I would hurt myself while getting off...

    The problem is that I'm somewhat disproportional. I need a frame with a longer top tube by about 5 cm than my seat tube. My current frame, Cannondale R700, has about the same for both.

    If the stem should be proportional, what would be proportional for a 48 frame?

  4. #4
    Senior Member
    Join Date
    Feb 2001
    Location
    England
    Posts
    12,195
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    You seem an ideal candidate for a compact-style frame which retains the length of a conventional design, but with the dropped top tube gives you more standover clearance. If you select a larger size (eg M) then you should get longer but not higher.
    For normal riders, an 8cm stem is about right for a small frame. You usually have about +-2cm of lattitude before steering becomes an issue but that really depends on the geometry of the frame and fork.
    If you can get an adjustable stem you can experiment with different positions.

  5. #5
    Senior Member Bontrager's Avatar
    Join Date
    Dec 2004
    Location
    Boulder, CO
    My Bikes
    Road, MTB, Folding, Commuting bikes...
    Posts
    2,339
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It might be cheaper going to a LBS and swapping out the stem than to buy a new frame
    08 Giant TCR Alliance Custom Build
    08 Trek 1000 Discovery Channel
    08 Fuji Outland Pro Custom Build (mostly Forge stuff)
    08 Forge Sawback 5xx MTB frame
    08 Downtube IX FS folding
    09.5 Downtube Front Suspension folding
    09 Diamondback Insight 1 flatbar road/beer
    09 Diamondback Clarity 1 flatbar road/beer
    1 bedroom apartment

  6. #6
    pluralis majestatis redfooj's Avatar
    Join Date
    Feb 2004
    Location
    DEN
    My Bikes
    blue fuji, black khs, yellow giant, and a little red 'Rosa
    Posts
    2,547
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Comatose51
    How do you judge what is the correct stem length for you?
    ride the bike with them on?

  7. #7
    if x=byh then x+1=byn blandin's Avatar
    Join Date
    Mar 2005
    Location
    Sacramento, CA
    My Bikes
    See signature
    Posts
    3,443
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I have the Ritchey WCS OS stem you referenced on my KHS Flite 2000. If that's the way you decide to go, it's really nice. I paid less for mine through Colorado Cyclist, but I haven't checked the current price.

  8. #8
    Senior Member biker7's Avatar
    Join Date
    Feb 2005
    Posts
    2,850
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Is a 8cm stem really an average stem size for a 48-50cm bike? Those stems are not that easy to find. Seems like most stems are in the 90cm-130 cm range. I just went from a 130cm stem to a 100cm stem on my new 61cm Bianchi Veloce because I deliberately went with a big frame for the longer steerer tube and higher handle bar knowing I would be on the long side of top tube length. Stand over was not an issue with my 35.25" PB to ground. I believe the hype about nervous steering with a short stem is ill advised. Case in point small bikes come with shorter stems as a rule and short wheel base bikes like cars are naturally more twitchy with speed because the wheel base is really the turning radius of a circle. I believe the trail, fork rake, steerer tube angle and overall wheel base of the bike are more important than the stem length.
    George

  9. #9
    DEADBEEF khuon's Avatar
    Join Date
    Aug 2002
    Location
    Catching his breath alongside a road near Seattle, WA USA
    My Bikes
    1999 K2 OzM, 2001 Aegis Aro Svelte
    Posts
    12,155
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It depends on the manufacturer as to what stem is appropriate. For instance, I ride a 48cm frame that's propotionally sized for a 110mm stem and a fork rake of 45mm. I'm told that many bike manufacturers design their bikes to handle neutrally with a stem in the 100mm to 120mm stem range.

    As far as judging the stem size, think about what you're trying to achieve. It sounds like your end goal is simply reach. But of course to determine reach, you'll need to weigh in a few factours for the new stem. I personally like to use this chart when comparing stems.

    1999 K2 OzM 2001 Aegis Aro Svelte OCP Club Member
    "Be liberal in what you accept, and conservative in what you send." -- Jon Postel, RFC1122

  10. #10
    Senior Member marcusbandito's Avatar
    Join Date
    Mar 2005
    Location
    Ann Arbor
    My Bikes
    Voodoo Wanga, Waterford RS, Gitane SS
    Posts
    275
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=Comatose51]How do you judge what is the correct stem length for you?


    I always start with the old rule about seeing your axle: The handle bars (where they meetthe stem) should obscure your view of your front axle when your riding with your hands on your brake hoods. If it doesn't, figure out where your hands would have to be and the stem length to get you there. (i get a friend with a ruler to help me with that part)

    You can get one from your LBS and try it out and see if it feels right. They shouldn't mind if you exchange for a different one. Don't forget to factor in the rise of the stem. That can affect the distance to the bars also.

    Also, thats a really cool chart!

  11. #11
    Senior Member biker7's Avatar
    Join Date
    Feb 2005
    Posts
    2,850
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Nice chart khuon. I have two bikes about the same size...60-61cm. One I can go no handed on and will track nicely and one I will end up in a ditch if I try the same thing.
    The stem doesn't factor in on either bike's propensity to track straight.
    I'm not saying stem length isn't a factor in steering sensitiviy...it is. Believe the geometry of the bike is a bigger factor. Going from 130mm to 100mm I almost feel no difference in how sensitive the turn in is or how stable my bike is at 30 mph...transparent. Other factor is handle bar width. Wider bars will slow steering down as well. One contrary factor to stem length not significantly increasing steering sensitivity is mechanical advantage. With a shorter stem yes the same displacement of the bars will rotate the steerer a larger angle...but...with higher effort due to reduced mechanical advantage. Anybody who is into cars and has put a smaller steering wheel on their car knows this. In theory the steering should be quicker but the companion effort increase in large measure counteracts the tendency for nervousness.
    George

  12. #12
    Burnin' and Lootin' ggg300's Avatar
    Join Date
    Dec 2004
    Location
    SoCA
    Posts
    2,718
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=marcusbandito]
    Quote Originally Posted by Comatose51
    How do you judge what is the correct stem length for you?


    I always start with the old rule about seeing your axle: The handle bars (where they meetthe stem) should obscure your view of your front axle when your riding with your hands on your brake hoods. If it doesn't, figure out where your hands would have to be and the stem length to get you there. (i get a friend with a ruler to help me with that part)

    You can get one from your LBS and try it out and see if it feels right. They shouldn't mind if you exchange for a different one. Don't forget to factor in the rise of the stem. That can affect the distance to the bars also.

    Also, thats a really cool chart!
    agree

    remember the shorter the stem the quricker the steer...IMHO
    my lbs let me try out diff ones....
    if it is a toss up I'd go for the longer,,,

  13. #13
    DEADBEEF khuon's Avatar
    Join Date
    Aug 2002
    Location
    Catching his breath alongside a road near Seattle, WA USA
    My Bikes
    1999 K2 OzM, 2001 Aegis Aro Svelte
    Posts
    12,155
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by biker7
    The stem doesn't factor in on either bike's propensity to track straight.
    I'm not saying stem length isn't a factor in steering sensitiviy...it is.
    Right. The stem comes into play in how it handles when steered. It has no bearing on stability during a no-hands situation. Although one could argue that the mass of the handlebars themselves hanging off the end of a longer stem will exert a greater moment on the steerer than if they were mounted to a shorter stem.
    1999 K2 OzM 2001 Aegis Aro Svelte OCP Club Member
    "Be liberal in what you accept, and conservative in what you send." -- Jon Postel, RFC1122

  14. #14
    Senior Member
    Join Date
    Mar 2005
    Posts
    420
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=marcusbandito]
    Quote Originally Posted by Comatose51
    How do you judge what is the correct stem length for you?


    I always start with the old rule about seeing your axle: The handle bars (where they meetthe stem) should obscure your view of your front axle when your riding with your hands on your brake hoods. If it doesn't, figure out where your hands would have to be and the stem length to get you there. (i get a friend with a ruler to help me with that part)

    You can get one from your LBS and try it out and see if it feels right. They shouldn't mind if you exchange for a different one. Don't forget to factor in the rise of the stem. That can affect the distance to the bars also.

    Also, thats a really cool chart!
    I've tried that and it's about 1 inch short from covering the front axle. Does it have to cover it or just obscure it? 100mm would probably obscure it. 110mm would totally cover it. My current one is 80mm so 100mm is the way to go?

  15. #15
    Senior Member
    Join Date
    Mar 2005
    Posts
    420
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by MichaelW
    You seem an ideal candidate for a compact-style frame which retains the length of a conventional design, but with the dropped top tube gives you more standover clearance. If you select a larger size (eg M) then you should get longer but not higher.
    For normal riders, an 8cm stem is about right for a small frame. You usually have about +-2cm of lattitude before steering becomes an issue but that really depends on the geometry of the frame and fork.
    If you can get an adjustable stem you can experiment with different positions.
    What's a compact frame?

  16. #16
    Senior Member biker7's Avatar
    Join Date
    Feb 2005
    Posts
    2,850
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The bar covering the handlebar while on the hoods is only a reference. It is not an absolute. Some like to stretch out a bit more and see a bit of hub behind the bars and some like to be in real tight. Too tight and your elbows can hit your peddling knee. If you sit on your seat and change your back angle with your hands on the hoods notice how much this reference changes when putting more and less elbow bend into the mix. We have all done this. More bend and the hub pops out the front....less bend and the hub pops out behind the bars. The ratio of torso height to arm length really influences this reference as well as a person's native flexibility. Your best bet if you want the best assurance which sounds like you do..which incidentally will change with more time in the saddle as most riders elongate with miles...is to buy a bunch of cheap stems and try different ones or buy an adjustable stem on e-bay and once you dial in the position you like purchase a stem with those specs.
    HTH,
    George

  17. #17
    Senior Member
    Join Date
    Mar 2005
    Posts
    420
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by biker7
    The bar covering the handlebar while on the hoods is only a reference. It is not an absolute. Some like to stretch out a bit more and see a bit of hub behind the bars and some like to be in real tight. Too tight and your elbows can hit your peddling knee. If you sit on your seat and change your back angle with your hands on the hoods notice how much this reference changes when putting more and less elbow bend into the mix. We have all done this. More bend and the hub pops out the front....less bend and the hub pops out behind the bars. The ratio of torso height to arm length really influences this reference as well as a person's native flexibility. Your best bet if you want the best assurance which sounds like you do..which incidentally will change with more time in the saddle as most riders elongate with miles...is to buy a bunch of cheap stems and try different ones or buy an adjustable stem on e-bay and once you dial in the position you like purchase a stem with those specs.
    HTH,
    George
    Is it better to be more elongated for someone with back problems?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •