|Question about stem length and handling||dgangi|
Oct 1, 2003 1:37 PM
|I recently bought a 54cm Fuji road bike and the frame fits me very well. However, this bike was spec'd with a 100mm stem (as are all 54cm bikes) and I was told by a roadie friend of mine to swap it out for a shorter stem (80mm) for the bike to fit me correctly. My torso length is short compared to my legs, so my reach isn't the same as others of my same height, hence the need for a shorter stem than stock (or so I am told).
My question is this -- will the shorter stem dramatically effect the handling of the bike? This is very true in the MTB world, where swapping out a 100mm stem to an 80mm can make the bike feel "twitchy". The same motion of the handlebar produces more motion at the wheel.
Obviously the same laws of physics apply to all bikes...no question there. But it's the application that has me curious. MTB riding is different than a road bike in that handlebar motions are constant -- gotta work with the terrain so the handlebars are always in motion. Therefore you notice any "twitchiness" of the geometry right away. On a road bike, handlebar motion is much less - you lean into turns, not steer into them (you are supposed to do the same on an MTB, but in practice that rarely happens on rocky singletrack), so I am not sure if there would be any noticeable difference between an 80mm and a 100mm stem on a road bike.
What has your experience been with a shorter stem on a road bike?
FYI - before doing a swap of the stem, I am going to get a second opinion from my LBS. The last thing I want is to be cramped on the bike because I followed some bad advice.
|won't hurt handling, but...||C-40|
Oct 1, 2003 3:48 PM
|there should be a good reason to swap stems. A 100mm is not long at all. Check for knee to elbow clearance when riding in the drops with your fingers in reach of the brake levers and the upper back horizontal. If you have a lot of clearance, then a shorter stem won't hurt, but keep it long enough to avoid knee to elbow overlap.
The main reason to switch to a shorter stem would be discomfort in the shoulder from a too-extreme angle between the upper arm and torso.
I'm assuming that you know that the saddle fore/aft position is for the purpose of adjusting the relationship of the body to the crank and NOT for the purpose of changing the reach to the handlebars. If you have the saddle adjusted arbitrarily, try reading the fit info at www.cyfacusa.com.
A shorter stem will make the bike steer a tiny bit quicker, but you will get accustomed to it on the first ride. There will also be an insignificant change to the front/rear weight balance (less than 1%).
|won't hurt handling, but...||dgangi|
Oct 1, 2003 6:27 PM
|Thanks for the information. I intended to get a second opinion from one of the local shops before replacing the stem. My friend's opinion may not be correct. And I will check that webiste too.
|I've got same question (sort-of)||ET_SoCal|
Oct 2, 2003 6:56 AM
|Just got my first road bike: (56cm), changed the 120 stem to a 90.
Still have to raise the bars higher so when in the hoods it's comfortable. My seat post shows 5" and is positioned correctly for knee2pedal, the top tube is the same length as my Mtb.
When my hands are on top of the bars my view of the hub/axel is hidden by the bars, (1" below seat) but if in the drops it's seven inches below the seat, but I have plenty of elbow/knee clearance...
Still tweaking in the cockpit, some have told me to research different bars, not sure if there is an 60cm stem out there...
BTW: that link: Gives me:
Oct 2, 2003 8:52 AM
This site might have been down temporarily, but it's up now.
As for comparing the TT lengths of an MTB to a road bike, thats, a bad idea. The brake hoods and drops extend far beyond the straight top section of the bars, so the reach will be a lot more. The seat tube angle on a road bike is also likely to be steeper, which further lengthens the TT.
Check the height of your saddle above the top tube (if the frame has a horizontal top tube. Measure near the (level) nose of the saddle. If it's more than 17-18cm, then it indicates that the frame size may actually be on the small size. A reach problem can also be due to a handlebars that are set too low. I tolerate a 9cm drop from the saddle to the top of the bars, but some folks can't.
There are a few bars out there with a short reach. I just bought Salsa Poco bars that have about a 15mm shorter reach than Deda or Easton bars. I chose this option rather than changing from a 100 to a 90 stem.
Oct 2, 2003 9:58 AM
|Have to research more&more&more...
the bar I have is an ITM "Super 330"
Width=440, Height=178mm, Reach=112mm, Radius-65mm
So guess I'll look for something with less reach & height.
|I use a 13cm with 54cm frame...||terzo rene|
Oct 2, 2003 2:52 PM
|Of course you have to get it all to fit you but I don't use anything less than a 12cm stem and just have to make sure the frame will let me do that. I just don't like the way shorter stems feel. I would not describe it as twitchy but that it responds too much to outside input and not enough to my own input with shorter stems. Especially noticeable on badly paved descents.|| |