A guy that I work with has shown an interest in tri and wants to do a early season duathlon with me. His bike is an old mountain bike with pieces missing and falling off. I’ve convinced him he will be better off buying a used road bike on the cheap than trying to fix his wreck. There is plenty on ebay that would suit his purpose and budget. But neither of use have any idea what size to look for. Person in question is 5’6" with 30" inseam. Any ideas of a ballpark size to look for?
The traditional Lemond formula is inseam x .67 measured in cm. 30" = 76.2 cm x .67 = 51.054.cm
Based on his inseam, 51 cm frame sounds pretty ball park and about where to start.
BTW, get him on a road bike with clip-ons first. Ride with roadies, learn bike handling skills and if he likes the sport, then get a tri bike. Road bikes handle better, are more versatile and a better way to go for a newbie triathlete.
I’ve convinced him he will be better off buying a used road bike "
“BTW, get him on a road bike with clip-ons first.”
Sorry, didn’t read your post close enough the first time.
Since I’m the exact same size, I would only go with a 49cm or 50. The 49 I have looks like a compact with plenty of seat post, but weighs less and has very little flex. Even though they look small, top tubes nowadays are quite long. When I first got the frame I just about returned it as it looked like a BMX frame, but once put together it is fantastic. As an added bonus and money saver, I wanted to get a TT frame in that size but the dealer told me to save my money as with tubes that short, aero ones would make little difference.