Originally Posted by
Psychocycles
I often hear that if you have too long & low a position you can get back pain, but I never hear whether too short a stem can cause the same. I occasionally get back pain while riding (doesn't happen with every ride, maybe 1/3 or 1/2 the time). I'm riding a size 54 cross bike with a -7 degree 100 mm stem that is slammed. I am 5'-11" (180 cm) and very flexible, as I can place my palms on the ground with straight legs without warming up. I don't have the budget right now for a professional bike fit, and am wondering if it's worth it to try to swap out stems for something with a greater degree of drop & longer, maybe 110 or 120 mm. What do you guys think?
I'm going to say save your money and get a professional fit. I just did and it cost me less than buying a new mid-range aluminum stem would have. I'm about an inch shorter than you, both my cross and road bikes are 56c, and I run 100mm on my road bike and 90mm on my cross bike. I also ran my stem slammed, -12 on the cross bike, -8 on the road. Road bike has a 3cm shorter head tube, so my positions were as close to each other as possible given the different frame dimentions. When I got my fitting on my road bike he was surprised I didn't have back pain because from his measurements I had my saddle too high my stem angle too low and my cleats too far forward.
My point being... it may not be your stem position that's causing your back pain. It may be saddle height, for/aft position, or you may end up making it worse by making your reach longer. In my mind, if your back is hurting, you are using it too much to support your body and may need to bring your center of gravity further back or more up, but then I'm not a pro fitter.