Carbonfiberboy 

For a cyclist, growth stimulus is not really the point. Fiber recruitment, also known as strength, is the point. Those new to lifting and doing strength work near or at their limit, meaning the last rep of a set is very difficult and the next would be impossible, will notice that their 1RM goes up much faster than could possibly be attributed to muscle growth. That strength increase is due to gradually increasing fiber recruitment. Muscles are very conservative structures, like much of our anatomy. They recruit as few fibers as necessary to do the job being asked of them. As is often pointed out, cycling is not a strength sport. The cyclist will normally only recruit a fraction of their muscle fibers. This works well because it reduces the metabolic workload, a good thing for a cyclist. However as the fibers being used tire, the muscle will ask additional fibers to come in and support the effort. Strength training improves the neuromuscular response to long-term stress. Won't hurt your sprint, either. During my fall/winter strength training, I put about 1/2" on my thighs, 1" on my upper arms, no more. My strength will go up about 50%. YMMV.

I'll go all the way to failure on lifts where stopping the lift or a having spot will work fine. I don't actually fail on lifts like squats where one can get hurt. I only go to failure once a week, a couple days before any hard ride or workout.

I recommend that beginning lifters or those who haven't lifted in quite a while, start with high reps, 20 or 30 - I use 30, though still failing a rep or two before the proposed end of the set. Research suggests that recruitment increases are about the same when going to failure, no matter the number of reps. High reps have a lower chance of injury while the athlete is perfecting their form, plus it increases endurance. More reps take more time is all. Theoretically one could do this on the bike, climbing in a big gear until one could not bring the next pedal around. I'd rather lift.