The effect of a shorter stem
jonny_trousers
Posts: 3,588
I understand stem size can have a detrimental effect on bike handling and was just wondering what I might expect if I was to go a little shorter (for comfort's sake)? At present my stem appears to be 11.5 cm centre to centre and ideally I would like to drop a cm. Would that be okay?
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Boardman Team 2011
All the talk about a 'twitchy' front end with a short stem is exaggerated. I can feel a slight difference in handling on a stem that's 2cm different on the same bike, but only a very slight difference.
Go for it - comfort is more important.
When people describe steering becoming more twitchy (assuming all other factors remain the same, fork rake, head angle etc) they mean it becomes faster. A 10mm difference won't make a huge difference in the speed of your steering, but could make quite a difference to your comfort.
Faith is the denial of observation so that Belief can be preserved
At slower speeds - up to about 20mph - I cannot feel much difference in the steering speed. At faster speeds however, there is certainly a notable difference. It doesn't feel twitchy, just more responsive; a flick of the handlebars results in a slightly quicker direction change.
The only downside to my new set-up, is riding no hands down hill at 30mph feels more likely to result in a tank slapper!
All the same, I think the difference it makes in general terms, probably boils down to frame geometry.
I wouldn't describe it as being more comfortable, for me it's about being able to hold a better position, relative to the saddle, to be more efficient. Is your stem flipped down or up? If it's down, it may be worth trying it flipped up.
Took me all of 20 seconds to adjust to my new stem which was a good 6-7cm shorter than my old one.
6-7cm?!? What the hell length are/were you using?
Were you riding a chopper ?
Faith is the denial of observation so that Belief can be preserved
FCN 4
if you use irrational measures to measure me, expect me to behave irrationally to measure up
That must be all in the mind - all the stem does is put the bars ahead of the steerer - if you're not holding the bars it won't make the slightest difference! Headtube angle, fork offset and trail might affect no-hands twitchiness, but the stem can't!
Where it will make a big difference is the comfort - here you really can feel the changes - and comfort is pretty much the most important thing - so make the change, get comfy and don't worry about any effect (perceived or real) that it might have on steering.
Obviously, if you are changing stem length by, let's say, 50mm - that will take some adaption - but I would suggest that there is something wrong with the size or set-up of the bike if you need such a drastic change to try and make it comfy.
The further the mass of the bars are from the centre of rotation the greater the inertia of angular momentum, so bar movement will be affected by stem length, even if your not touching them.
That must be all in the mind - all the stem does is put the bars ahead of the steerer - if you're not holding the bars it won't make the slightest difference! Headtube angle, fork offset and trail might affect no-hands twitchiness, but the stem can't![/quote]
It is not in the mid Sir - I'm not talking censored here! There is definitely a difference for me in the feel of my bike, including no hands!
It was a long one, and now it's a really short one.
It's maybe 6-7 cm long? I just bought the smallest one there was.
So you went from a Boonen-esque 140mm stem to a 70mm one? Yes - that would be a massive change in fit and handling.
For me it's just to relieve a little pressure I am feeling in my shoulders (traps?). A 10mm drop sounds like just the job. Don't suppose anyone knows what size I should be looking at to fit onto a bog standard Condor Fratello steerer?
Interesting to hear that actual size and stated size is not always the same, however. I'll take mine off and have a look if it is marked in any way.
Cheers!
It was big change in fit. Didn't notice the handling much.
I run a 90mm on my Fratello - but that works for me - may not for you!
It might be worth dropping into Condor if you can and sitting on their jig again to try different stem lengths and how they fit.
I'm wondering if it's because the headset bearings are loaded slightly less than they were, having presumably removed / replaced the top cap during the stem swap?? Any headset noise / movement?
Maybe! I'm paranoid about overloading the bearings, so tend to under do it, so to speak. There's no play/noise in the headset. I may give it a tweak and see what happens.
Interesting anyway.
That makes a lot of sense. I was thinking about buying online to save myself a few quid, but I'm going to get a wider set of bars when I take my bike into Condor for a service in a couple of weeks time, so it seems like a good idea to measure it all up at once.