I'm grateful for all those who replied to my previous question about 650 v 700 wheels on a triathlon bike. I thought the thread was informative, even if there is not a universal agreement. That brings me to my next question, which has to do with fitting on a tri bike. I ride a size 54 road bike, but have been told by a lot of triathletes that this translates to approximately a size 52 tri bike. My local bike shop, which does not stock tri bikes, says rather emphatically this is not true. They acknowledge that a lot of triathletes try to squeeze on to smaller bikes, presumably to save some weight. What's the opinion about fitting on tri bikes? Should I knock off two sizes from my road bike and use that to fit the tri or should I use the same size as my road bike?
Usually knock off at least one size for a tri bike. It is NOT for weight savings, but rather for obtaining proper body geometry angles. You want your arms at 90 degrees to your torso and torso as close to parallel to your top tube as possible, as well as allowing your legs to extend no more than 150 at the bottom of your stroke.
I was recentley measured and fitted for a new tri bike, and it was a size smaller than the two road bikes I had and they were all the same make of bike. I would make sure you get fitted properley for the new bike.
Usually knock off at least one size for a tri bike. It is NOT for weight savings, but rather for obtaining proper body geometry angles. You want your arms at 90 degrees to your torso and torso as close to parallel to your top tube as possible, as well as allowing your legs to extend no more than 150 at the bottom of your stroke.
And realize that one 54 cm tri bike is not the same as another 54 cm tri bike. It depends a lot on how the company measures the bike. The standard c-t-c measuring protocol isn't as relevant for a tri bike. What is important is that you can achieve the proper body angles comfortably on the bike. I know 2 people that have been measured for a tri bike and it wasn't until they had a proper fit done on the bike that they realized they needed a different size (body proportions were slightly unusual i.e. longer torso & arms/shorter legs).
