I have weak, spindly legs. I can’t generate much power on the bike. I do hill repeats and big gear intervals, but still don’t see much improvement (I’ve been do tri’s for 3 years). I need to hit the weight room and build some muscle. I also want to purchase a (fairly) cheap leg press machine (< $500) for home use. Any recommendations for a leg press machine from those who use them?
borg, don’t do the machine. but some dumbells instead and go outside to lunge. buy weights that are light (like 15 or 20) and then buy heavy (like 30 or 40 or 50). two times a week go outside and do walking lunges. one time long–take the 15’s and walk a long distance and return, 3 sets. the next time (or even next week) do heavy weights and walk for 60 seconds and turn around, rest 30 seconds and come home, 3 sets. i guarantee you this will pump you up at a fraction of a cost. if you want to throw in a bench, do step ups with the weights. then there are also side lunges. i’m telling you the strongest guys I know (who are literally power lifters and bodybuilders) swear by this. if you want to add even more to this, get a free standing squat rack…the possiblities are endless with just these three things (dumbs, bench, squat rack)…and will save you a ton. oh, and look in your area’s trading post for a squat rack–often they are things that people want to unload because they take up space (and most people fall off the wagon).
PM if you want more ideas–I used to be a personal trainer 
good luck,
kittycat
oh, and more than the weight room, you need to eat some protein baby. if you don’t do it already, a protein shake would help you gain.
Ride the bike - don’t do the weights. Look at people like Pantani and Boardman - the Hour record holder. They don’t have huge legs.
I have big, tree trunk legs for my weight and height. I wish I could have spindly legs. But hours and hours of riding has not changed that. I also wished I had not lifted so much weight when I was in high school.
You want strong legs for cycling? Do lunges. No machine needed. Just go to the park, or the sidewalk, and start going. Do 'em every other day, or 3 times per week. You will be sore as hell for the first few weeks. When you get up to 300 in a row (no resting or falling down) you’re getting somewhere. My favorite set is 2x100 warmup, 1x300. I do it at a park that has a very slight incline.
Best training I’ve ever done for my chicken legs.