Advice for the bad-backed bicyclist from another bad-backed bicyclist. You most probably can get your bike to work for you; but you will need to be patient. First off, never, ever increase your mileage or time on the bike radically; cause if you do, you will pay for it. You must increase things even more incrementally than most others do because you have a weak link and it needs more time to adjust to more time in the saddle; more climbing than you are used to; pushing harder than normal; etc. All these things must be increased thoughtfully, or you will suffer.

I do not know how your bike is set up, but I have, for years, even when I raced, run a higher handlebar than some other racers; mostly because if I had my bars lower, I would die, have absolutely no power in my legs and would go slower rather than faster. The aerodynamics of the fit will not help you go faster if your back refuses to be in that position and you lose power. So, I run all my road bikes handlebars pretty level with my seat, or a little bit above. A 1/4 of an inch difference and I can suffer big time! So, try raising your handlebar to level with your seat is my suggestion to you. I would also look at the reach, cause longer reach also changes your hip angle and can give you back pain. Again, I do not know how you fit now, but you should keep this in mind. (you do not want to be too scrunched up however) THis is all a fine balancing act!

Someone above noted that you should not change your seat height too much too dramatically and they are correct, so if you are changing your seat height do it slowly. If your seat is a little too high, it can cause back pain because it again changes the angle of your hips as you sit on the saddle. Back pain can be exacerbated by tight hamstrings and if they are tight, then you need to lower your seat just a little tiny bit. That may help in the fit department. I lower my seat just a little in the winter time because 1) I'm usually wearing tights which makes me sit higher on the seat; and 2) my hamstrings are usually tighter due to the coldness of the weather.

Because these changes are very small, you can see that you have to play with your fit just a little until you can get it right.

FINALLY, the most important thing I can think of with regard to back pain is Stretch, Stretch, and Stretch. Make sure you have stretched everything well; i.e. hamstrings, IT bands, back, shoulders etc. I have found that easy Yoga is great for this! Also, ibuprofen, if you can handle it, is a wonder drug; and CORE STRENGTH is an absolute must. You must do crunches, planks, whatever else you can to strengthen the front so that it can compensate for the back!

Hope this helps. Hang in there, it is no fun to have back pain; but if you try to do all the above, you will, with patience, be able to enjoy that lovely bike! spoke