Maximum stem length??

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Maximum stem length??

Postby RRalphy » Sun Jan 13, 2013 1:41 pm

Hi just a quick question about stem lengt.
I am looking at getting a new frame that has a top tube that is 2cm less than my current frame can I compensate for this by just getting a longer stem? It would mean I would need a 130mm stem, are there any downsides to using a longer stem rather than getting a larger frame? Also how long do they make stems?
Thanks
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by BNA » Sun Jan 13, 2013 2:11 pm

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Re: Maximum stem length??

Postby Nobody » Sun Jan 13, 2013 2:11 pm

RRalphy wrote:Hi just a quick question about stem lengt.
I am looking at getting a new frame that has a top tube that is 2cm less than my current frame can I compensate for this by just getting a longer stem? It would mean I would need a 130mm stem, are there any downsides to using a longer stem rather than getting a larger frame? Also how long do they make stems?
Thanks
Yes, you can get 130mm stems.

In my opinion the main disadvantage of a shorter frame is a shorter BB to front hub which makes it more likely for you to go over the bars during heavy/emergency braking, so reduces your maximum braking ability.

Also longer stems will change steering speed.

IMO better to get the right frame size.
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Re: Maximum stem length??

Postby mitzikatzi » Sun Jan 13, 2013 2:41 pm

Google reveals many use a 130mm stem (or more).

Stem Length

Last stop – finding a stem length. This step is all about positioning your handlebars so that they are under your upper body in a spot that is natural and easy for your arms to get too. The correct stem length doesn’t “stretch you out”. Issues of back comfort are best accommodated by stem height, not horizontal distance.

To accomplish this, get on your bicycle with a correctly adjusted seat position (both for height and fore-aft position) and lean into a comfortable ‘drop’ position with the handlebar. You may need some help to support the bar in the air (since you don’t have a stem yet), but we’re looking for the point where the center of the bar tends to obscure the front hub when you glance down. When you find that point, have your helper make a horizontal measurement back to the center of the steerer tube from the center of the bar – that’s your stem length. Talking about a traditional frame and fairly average body plan; if the frame is the correct size you should end up needing somewhere between a 90mm to 130mm stem and have a gentle bend at the elbow. If you are well outside that, something else went wrong somewhere along the line with your frame size or seat position.

The stem length formula does assume your arm length is reasonably proportional to the rest of your body. But most people with short arms tend to have short torsos and/or legs, so this usually works out okay. When in doubt, try to duplicate the arm angle you see on other cyclists.
from here

Bike fit is a series of compromises here. Stem length is just one factor to be considered.
Xplora wrote: Do not get cheap SPDs, your body will hurt you.

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Re: Maximum stem length??

Postby RRalphy » Sun Jan 13, 2013 2:54 pm

Thanks for the info guys
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Re: Maximum stem length??

Postby brentono » Sun Jan 13, 2013 3:07 pm

Personally, if your not using a 100-110mm stem, your on the wrong size bike.
Floor-to-pubic bone measurement, is the best guide.
Standover clearance, is overrated.
People sizing bikes, by the top tube length, It doesn't work.

Might wonder why you are going for a new frame 2cm smaller top bar, but can only
think that your current frame is too big (by PBM) and this means the seatbar may be shorter, too?
On a bike with a 73.5-degree head tube, lowering topbar 2cm, brings it brings it forward 0.75cm, also.
Maybe just try your original stem, in your new bike and go from there.
have you measured your Floor-to-pubic bone measurement?
Just some thoughts.
Cheers
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Re: Maximum stem length??

Postby warthog1 » Sun Jan 13, 2013 3:40 pm

Got a 130 on one frame and a 120 on another. I like a longer stem and shorter head tube. Works if you are reasonably flexible.
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Re: Maximum stem length??

Postby brentono » Sun Jan 13, 2013 5:05 pm

warthog1 wrote:Got a 130 on one frame and a 120 on another. I like a longer stem and shorter head tube. Works if you are reasonably flexible.


May work if your well over 6'
And the caveat goes, with Floor-to-pubic bone measurement against Trunk Length.
The ratio for me was very high Trunk/PBR for my height, so the 110 worked well. I was under 6'
Depends on how far you have to ride that way, also.
I had raced the old-ton, on my setup, and performed well for a Trackie. 100miles. :D
Ralphy hasn't really given enough info, for help to benefit.
Cheers
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