Road Cycling - Stem length importance?

I recently finished building my bike, it's a 54 cm frame, with a 10 cm stem. I'm thinking that the stem could be 1 or 2 cm longer. But I'm not sure how much longer it should be, I don't want to pay money for a bike shop to tell me how long the stem should be. When just riding around the block (haven't gone for a long ride yet), it feels fine.

Is another cm or two in stem length really going to make a huge difference? It's just that when I'm on the drops, I can stretch my back out longer by moving my torso forward, and my upper arm angle gets steeper. Or I can hunch more and set my torso back, and my upper arms stretch out more.

It's so close I can't even tell if I need a longer stem or not. How important is it in racing and training, if I MIGHT need a longer stem. Is it just a comfort difference, not a performance issue or what?

If it's that close, I don't want to spend more money on buying another stem if I don't need to.

If it "feels" right, why do you "think" you might need a longer stem? Try the 10 for awhile and see how it feels. Regarding feel, I would think a cm or 2 would actually be a noticable difference - for me, anyways. 1 cm = about 0.4 inches unless my grade school math is failing me.

Or spend the money and go in for a bike fitting somewhere.

It's just that I feel a tiny bit cramped. Like I said, sometimes it feels better to move my upper body forward, and my arms stay where they are. It might be more comfortable to be able to move my upper body forward and my hands be able to go forward as well. I guess this way though, I have the option of staying back or moving forward. If it's too long, I can't go back.

How much do your local bike stores run road stems for? I just want to compare because my LBS stems are a bit pricey.

You can price stems out online for some sense.

www.performance.com

But I think some sort of fitting might make sense. There's also another stem thread kickign around here that talks about some of the same stuff.

FWIW, I am contemplating going from a 12cm to an 11cm on my 59cm Litespeed.

Oh and what about how far back the seat is in comparison to the crank? I moved the seat back so that the clamp is on the most forward part of the seat rails. Will I still be able to transfer power as efficiently moving it in this position?

Try jumping into this thread. I am certainly not an expert on bike fitting nor do I play one on TV. Seat position relative to the cranks is important, and I don't think you just want to slide the seat as far forward as you can to get closer to the handlebars.

I'd find a fitter if I were you.

http://www.bikeforums.net/showthread.php?t=58428

The one link to the fitting article on competetive cylist was interesting too.

I recently finished building my bike, it's a 54 cm frame, with a 10 cm stem. I'm thinking that the stem could be 1 or 2 cm longer. But I'm not sure how much longer it should be, I don't want to pay money for a bike shop to tell me how long the stem should be. When just riding around the block (haven't gone for a long ride yet), it feels fine.

Is another cm or two in stem length really going to make a huge difference? It's just that when I'm on the drops, I can stretch my back out longer by moving my torso forward, and my upper arm angle gets steeper. Or I can hunch more and set my torso back, and my upper arms stretch out more.

It's so close I can't even tell if I need a longer stem or not. How important is it in racing and training, if I MIGHT need a longer stem. Is it just a comfort difference, not a performance issue or what?

If it's that close, I don't want to spend more money on buying another stem if I don't need to.

fwiw
as a general rule of thumb which basically just gives you a line of reasoning to stop worrying, if you are in the drops like on a fast decent type situation than as you sight down to your front hub the top bar of the handle bar should obstruct the view of the hub or at least be a little after it but never before. Then ride the bike for several miles like 300 and make any changes from there probably 10mm at a time. Don't make these corrections with the saddle adjustment. That is based on an entirely different set of rules...

if your stem is too long, the steering will be a little more slack... im not sure how much... but comfort wise 1/2cm will make a big diff! try pushing your seat back a bit also.. or getting a slant-back seatpost...

if you find that you need to make a lot of adjustments to your bike for comfort.. maybe its time to think about a new frame

Numerous sources I read say that when you are on the brake hoods, the handlbars should obstruct your view of the front hub. On my bike, this is exactly how it is, no doubt about that. If I had a longer stem though, wouldn't this test still give the same result?

If I move my upper body and head forward without changing the stem, the handlebars are behind the hub. If my body stays in the same position, but I get a longer stem, now it obstructs the view again. So I can't really use that test...

Numerous sources I read say that when you are on the brake hoods, the handlbars should obstruct your view of the front hub. On my bike, this is exactly how it is, no doubt about that. If I had a longer stem though, wouldn't this test still give the same result?

I agree with those sources, sparknote. If ones butt is properly and comfortably positioned on the saddle, and ones hands are atop the brake hoods instead of in the drops, the handlebars should obscure the front hub. It's that way on my ride, and I am as comfortable as a bug on a peach. :)

Numerous sources I read say that when you are on the brake hoods, the handlbars should obstruct your view of the front hub. On my bike, this is exactly how it is, no doubt about that. If I had a longer stem though, wouldn't this test still give the same result?

If I move my upper body and head forward without changing the stem, the handlebars are behind the hub. If my body stays in the same position, but I get a longer stem, now it obstructs the view again. So I can't really use that test...

this is a rule of thumb to get you close. the fine tuning depends on many factors. I think you need to nail down your seat position. then check to make sure your position is comfortable for a 40 mile ride. check to make sure your knees don't hit the handlebars.

this is a rule of thumb to get you close. the fine tuning depends on many factors. I think you need to nail down your seat position. then check to make sure your position is comfortable for a 40 mile ride. check to make sure your knees don't hit the handlebars.
I've read that it's when your hands are IN THE DROPS that the front hub should be obscurred...not the hoods? Which is true?

I've read that it's when your hands are IN THE DROPS that the front hub should be obscurred...not the hoods? Which is true?
Yea like I said above too. I just looked in my book and it does say drops. But it's all relative and it is really a very fuzzy rule of thumb. I think the main point is to be in a fast aero position weather it be drops or hoods...

...and I don't think you just want to slide the seat as far forward as you can to get closer to the handlebars.


Moving the seat is going to change your riding angle. Depending on what you are wanting to do will determine the correct angle. Typically road cyclists will have a 74 degree seat angle, triathletes will have a 76 degree seat angle. The angle is the straight line that runs down the seat tube from the seat to the crank. Moving the seat forward and backward basically changes that riding angle. The position of the seat will change the way the muscles work...

All that to say, I would adjust the seat first for your sport, then adjust the stem to dial it all in. Also, there is something to be said for initial comfort, but I have noticed that my body adjusts to the different positions given some time in the saddle. I would set it up properly in the first place and ride a while, if you really feel uncomfortable, make small adjustments.