Agreed with Denver- resistance training is the best weight bearing activity you can do to keep the bones strengthened and prevent osteoperosis in old age- it helps maintain bone density as you get older.
Besides that, I just returned from a fitness convention where the top researchers in the field were lecturing on resistance training in older populations, and the latest research studies done from observing older patients in hospitals showed that when a high percentage of older people with low density bone issues had hip fractures, they died within 2- 3 years. So at the very least, do the weights to help combat bone density issues later in life.
Another thing you may want to consider- why go with bodybuilders on training rides or consult with bodybuilders on what a cyclist should do for weights? That makes absolutely no sense at all. I would venture to think that the reason why weights did not work in this instance was probably because by going to a group of people who knew absolutely NOTHING about cycling, you were not able to get any correct information on how to correctly train to get maximum results with weights. Done correctly, weight training will maintain muscle mass, prevent loss of fast twitch muscle fibers, and help increase your power output. As I always say, it's all about putting together a strong periodization program, and that includes time with strength training too. With a solid program of strength training and cardiovascular training, you should see a marked improvement in your cycling skills. If you don't see it, you just haven't done it right, that's all.
Finally, keep in mind that weight lifting is NOT a cardiovascular training activity- cycling is, running is, rowing is... but weight training is a basically anaerobic, short burst energy exercise. There are no direct cardiovascular gains made from weight lifting.
Koffee