Triathlon - Tri bike fit for a short guy (5'4"), help!

Looking to buy my first tri bike and need help with sizing issues. In particular, if I am right on the line between a 48cm that runs 650c wheels, or a 51cm running 700c wheels, is there an advantage one way or the other?

I have tried extensively to find a LBS that can help, but there just aren't any where I'm working right now. The closest I've come was one shop that was working on a customer's 54cm Cervelo P2C Ultegra, which was way to big for me. Nobody else even carries any triathlon bikes.

I'm 130lbs, 5'4" with a 29.75" inseam (75.6cm) and 53" sternum to floor measurement (137.2cm). Taking my inseam in cm - 27.5 comes to 48.1 for frame size. However, using my inseam, sternum to floor and arm measurements yields a top tube length of 51-53cm. This places me in between the sizes for many of the bikes I've looked at. My road bike is a 50cm Motobecane aluminum frame which I love and it fits me great.

I'm looking at the Felt B16 or Cervelo P1, and maybe the Felt B12 or Cervelo P2 SL Ultegra. The latter two bikes are slightly over my budget, but I could make them work if there's a big enough benefit. I also looked at the Kestrel Talon Tri (SL) and Motobecane Nemesis, but didn't find much positive written about these two. My thought was that I could buy a $1500-2000 bike and then look for some lightly used race wheels to round out the package.

Any help would be appreicated!

I was in the same position. 5'4", 125 lbs, 28ish inch inseam. In regards to the 650 wheels versus the 700 wheels, the big downside is that a pair of race wheels on the TT bike will not go on the road bike, and if you flat, you can't borrow a tube from anybody else. Also you are vastly limited on what race wheels you can buy (Zipp 303 or 404s or HED H3, Jet 60 and 90, no discs other than some used Renn discs on Ebay/Slowtwitch). So that sucks.

You probably want a shorter top tube length than what you have on your road bike. Most people drop a size from their road bike to TT bike. Too long of a top tube is really bad for getting a good position. If you have to order something without getting to test it out and set up a fit, I would err on the side of the smaller top tube.

It is hard to beat the Cervelo P2 with Ultegra build in a price vs aero debate. The only downside of that build is that they spec a 170 mm crank. I swapped out to a 165 mm crank and it made a huge difference in the position I could get into.

Edit: the 48 P2 Ultegra build has the 170 crank.

Thanks for the input; definitely wasn't considering the ability to swap wheels with my road bike, but that could be a big factor.

I thought it would be an issue for me as well until I realized that I probably will never be seriously racing crits or road races. Since I only do group rides and leave the cat 4 crash fests to other folks, I decided that it was a non-issue for me.

Check out Nytro.com One of my training buddies is 5'4" and they were very helpful in helping him pick a bike.

What did you end up getting and why?

I would recommend looking at Quintana Roo because they initially catered to shorter people and women (I'm a guy but pretty short at 5'3")

whow! I didn't realize how old this was.

I'm 5'5" so vertically challenged as well. How well does the extra small fit you?

I'm 5'5" so vertically challenged as well. How well does the extra small fit you?

It fits me perfect! I took the dimensions from my Zipp2001 and carried them over to the QRoo. I have everything on the max shortness (without having to cut the seat tube) and it worked out great. I also have the nose of the saddle 3-cm in front of the center of the bottom bracket which is also maxed out. I can move the seat backward but not forward any farther. So far this bike has been a dream come true and we've got lucky with most of it. My only complaint has to do with the SRAM front derailleur but that is an easy fix/replacement.