I have been intigued by triathilons in the past and after discussing it with a friend at work, am going to try a sprint. I curnetly swim, run and lift weights. I am 5'10", 240 lbs, and wear a size 50 jacket. I lifted weights to gain mass and swam for flexability. I anticipate having to drop some mass during training for my new endevours.
I have 9 people in my house and work 86 hours (2 jobs). Needless to say, budget is an issue. I was told at one bike shop I needed a 58cm frame. I've been reading reviews trying to decide what to buy. Looks like I'll be going with a used enrty level road bike from my local bike shop. I would appreciate any advice anyone has.
After reading reviews, I'm curious, how do I know how high to set the seat and handlebars? Again, I would appreciate any advice for someone new the sport.

For advice on which bike to buy, check out the sticky thread in this forum on this subject.

Seat height: there are many ways to measure this, but perhaps the most straightforward is to take a picture of yourself, while you're pedaling, at the most extended part of your pedal stroke, and measure the angle that your upper and lower leg make with respect to each other. This angle should be 150 degrees, plus or minus 2-3 degres.

Handlebar height: basically, IMO get them as low as you can, and still be comfortable enough during rides of the distance of your race. The lower you can get the bars, the more aerodynamic you'll be

Also, if you plan on doing more triathlons in the future, know that the optimum body composition for triathlons is basically as light as possible (muscle AND fat). At 5'7" I can tell a *huge* difference between trying to race at 165lbs (last season) and racing at 143lbs (this season)--especially during the run portion, where I'm around 30 secs/mile faster just due to the weight loss. If your 240 lbs is mostly muscle mass, then your speed gains may not be as dramatic, but it's still something to consider if you are interested in this sport for the long-term

Good luck!

I wouldn't worry about the swim,on race day focus on staying relaxed esspecially in the the swim. I set my seat hight, so that when I'm spinning as fast as possable, I don't feel a whip or snapping around the knee(knee allways has some bend in it),too low =less power. But start your cycling training as soon as possable,when I'm out of cycling shape I suffer too much and theres less mental energy for the run.
Just some advice from a knuklehead !

5'10" on a 58cm seems a bit on the big side IMO(I'm 5'11" and I ride a 56)....you may want to get another opinion and definately ride some different sizes to see what feels best.

i am 6'2 and ride 58's so wonder a bit about the sizing they told you...on the other hand you may have very long legs..... welcome and remember to have fun, tri's are a blast and they are severely addictive.....best of luck to you.