Stem length and bike handling
#26
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You're kinda correct about stem length. Stem length does affect handling, but comparing the 100mm stem on your city bike to the 110mm stem on my road racing bike, I guarantee that my bike is "twitchier" than yours. That is a function of rake and trail, meaning the geometry of the bike as a system. When talking stem length, it must be understood that a stem of a given length on one bike compared to a stem of different length on a different bike is incomparable, unless the two bikes have (near) identical geometry. That all said, yes, a shorter stem in general will enable faster steering, especially at low speed, and a longer stem in general will provide a more stable platform at high speed.
Your implication that there is a universal fit for handlebar width, just like a discussion of stem length that says there is a universal rule about which length handles which way, is also incorrect. On MTBs riders typically use bars wider than their shoulders, while on road racing bikes they use bars that are shoulder width or narrower. There are very specific reasons for this, and they have little to do with fit. You are correct though that the choice of bar width will impact steering. MTBs use wider bars for the advantages to steering, especially for technical riding. Whereas road bikes employ narrower bars, often as narrow as a rider can tolerate (fit), in order to get the most aerodynamic benefit possible by keeping the elbows in making torso as compact as possible to reduce the frontal area of the rider.
Your implication that there is a universal fit for handlebar width, just like a discussion of stem length that says there is a universal rule about which length handles which way, is also incorrect. On MTBs riders typically use bars wider than their shoulders, while on road racing bikes they use bars that are shoulder width or narrower. There are very specific reasons for this, and they have little to do with fit. You are correct though that the choice of bar width will impact steering. MTBs use wider bars for the advantages to steering, especially for technical riding. Whereas road bikes employ narrower bars, often as narrow as a rider can tolerate (fit), in order to get the most aerodynamic benefit possible by keeping the elbows in making torso as compact as possible to reduce the frontal area of the rider.
How do you feel about using shoulder width bars for trail riding?
Observations about trail is totally correct. Stem length will always be a matter of fit.
#27
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Youre completely right. As a rule of thumb, id say that bars around shoulder width would be a good starting point, for any rider, regardless of terrain. You can adapt to different lengths more effectively from that point onwards.
How do you feel about using shoulder width bars for trail riding?
Observations about trail is totally correct. Stem length will always be a matter of fit.
How do you feel about using shoulder width bars for trail riding?
Observations about trail is totally correct. Stem length will always be a matter of fit.
I don't have feelings about bar width on trails, but I do have some practical knowledge...but trail is an awfully non-specific term, so I can't really say. What kind of trail riding are you talking about?
Last edited by Badger6; 04-18-21 at 01:37 AM.
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#28
Junior Member
I go with pretty much as various post, my 10c. I recently changed a 90mm to a 70mm, I was surprised how much more comfortable the drops became.
So the bike is 55cm, and I'm probably closer to a 54cm in frame size, but it just struck me, most of the time we're trying to go lower and get more reach. Most of the time we will size according to how we hold the brake handles! But that means we aren't always getting an optimal drop position.
So just a suggestion, if you don't ride in drops as much as you would like, maybe try a shorter stem.
So the bike is 55cm, and I'm probably closer to a 54cm in frame size, but it just struck me, most of the time we're trying to go lower and get more reach. Most of the time we will size according to how we hold the brake handles! But that means we aren't always getting an optimal drop position.
So just a suggestion, if you don't ride in drops as much as you would like, maybe try a shorter stem.
#29
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Thanks all for the discussion. Lot of interesting points made.
I did the balance test with the bike in question and the elbow angle. The existing stem supports those two reference tests.
Based on the discussion, I would be surprised if 10mm makes a difference. I have several "race" geometry bikes that are all slightly different dimensions from 58 to 61 ctc st. Most are square or within a tolerance measurement of one. I would like to replicate fit on all the bikes but have a limited number of stems to choose from. This small difference, if any, allows for using the existing ones.
I did the balance test with the bike in question and the elbow angle. The existing stem supports those two reference tests.
Based on the discussion, I would be surprised if 10mm makes a difference. I have several "race" geometry bikes that are all slightly different dimensions from 58 to 61 ctc st. Most are square or within a tolerance measurement of one. I would like to replicate fit on all the bikes but have a limited number of stems to choose from. This small difference, if any, allows for using the existing ones.
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I don't know if this answers your question, but longer stems are more stable and shorter stems are more twitchy. I wouldn't worry about hiding the front hub view. Do what feels comfortable or get a bike fit. I fought getting a bike fit, but when I finally gave in and got a bike fit, it was the best money I have spent on my bike.
#31
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Purely empirically, with no data or theory behind it:
Small differences in stem length don't have much effect on handling. If you've got to use a really short or really long stem to make the bike fit, it's likely to handle weird. Also, different people like their bikes to handle differently. Personal preferences matter a lot.
--Shannon
Small differences in stem length don't have much effect on handling. If you've got to use a really short or really long stem to make the bike fit, it's likely to handle weird. Also, different people like their bikes to handle differently. Personal preferences matter a lot.
--Shannon
#32
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@Trakhak made the point that you steer with your body. That hit home for me as it is part of the efficient style of riding on the street, anyway.
I think new riders, or infrequent riders, often try to steer the bike as they are afraid they will fall over if they lean. Stability is attained over 10mph anyway so if they are afraid of speed and stay below the stability threshold, they steer a lot with the handlebars.
Fun reading the responses. Thanks to all. I am comfortable swapping out a stem that is 10mm different from the one on there now, knowing it wont' make a difference. Well I will likely adapt knowingly or not.
I think new riders, or infrequent riders, often try to steer the bike as they are afraid they will fall over if they lean. Stability is attained over 10mph anyway so if they are afraid of speed and stay below the stability threshold, they steer a lot with the handlebars.
Fun reading the responses. Thanks to all. I am comfortable swapping out a stem that is 10mm different from the one on there now, knowing it wont' make a difference. Well I will likely adapt knowingly or not.
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