I consider myself mostly a runner - started a year ago after years of inactivity from knee surgeries and am now aiming towards a marathon. Because of my bad knee, I have trouble working my quads well though. So I just bought what I hope is a decent bike - Trek 4300 with semi-slicks to do some hill climbing and stuff. I'm hoping this will be sufficient quad training to balance my distance running. I've also got excellent upper body strength from years of weight-training and am a good swimmer, so, why not do a triathalon? I'm thinking in the normal sprint variety that I really don't need to do much swim prep work. I mean, if I can cover the distance, how much time am I really going to save, even if I swim twice a week? (my main push is still to increase my running mileage). I guess that would be my main question. I'm also wondering about the bike gears. My last bike was a ten speed. This is a 24. Is there a guide to effective use of gears? Seems like the gear ranges off the small front sprocket are a lot narrower than on the large. Also, if I am mainly interested in quad strenghening, does it make any sense to lower the seat slightly (for training) or would that just be bad form? Do some folks do tri's on hybrids, like my Trek, or are the gear ratios just no good for roads? These would almost certainly be sprint tris. Lotsa Questions.