Ok - you guys are the guys in the know.
I was just about to buy the Orbea Ordu 57cm and then got hung up on seat tube angle - 74/76 degrees vs. the 78 plus that I am aspiring to. Now I am about to buy the Crevelo P3C. Here is the delima - 58 or 56cm. Frames are used and I have access to each size - cervelo service wont help since I am not ordering the frame from them. I am 6’0 tall with feet together, inseam of 87cm LBS measured. They dont handle tri bike geometry and couldn’t help. I can work with stems and bars but dont want to under- or oversize the frame. Any thoughts would be greatly appreciated.
if it helps any, I have a size 55 P3-SL and I am 5’11 1/2 with inseam of 32 and it fits me perfectly.
Definitely not a 58. Possibly a 54, but between the two sizes you are choosing from, the 56 for certain.
Based on me personally, 6’ with an 84cm inseam, the 56 worked better, but I would possibly even look at a 54.
As you may have read from another thread I just returned from watching some wind tunnel tests and a rather detailed class on aerodynamics as applied to bicycle design and positioning.
I don’t want to tell you which bike to buy outright, but I will give you some insights based on this wind tunnel experience at Allied Aerospace and from previous wind tunnel testing and practical experience I’ve had in the shop and out on the road:
There are a lot of bikes in the market place that feature attractive looking “aero styling”. That is to say, they look like they have been designed from an aerodynamic **origin **when in fact that did not **originate **from the wind tunnel but may have been conceived elsewhere and then put in the wind tunnel in an attempt to validate the design. That is a backwards approach to bicycle design for optimal aerodynamics and positioning. An ideal appraoch would be to put a rider in a wind tunnel in a good riding posture on top of a big lump of soft, pliable, easily erroded clay. Turn on the wind and let it errode the clay away over time. When there is just enough of the clay left to support the rider and no more- boom- there’s your optimal frame design. It would be a very smooth shape with no sharp edges and a minimal frontal area. Air would flow smoothly and easily over and around it. It would be a simple design free of ridges, sudden transitions and other styling cues. Look for designs that feature these smooth transitions and simple shapes. Ridges and sharp edges along the air flow cause the boundary layer to “depart” and raise drag coefficients, especially at low speeds from 18-22 m.p.h. where aerodyanmics is such a gentle craft and critically important. Truely aerodynamic frames are an amalgam of very small details working together synergistically to produce an end result with lower drag. One bike we looked at had over 35 seperate, minor refinements tha each optimized the flow of air over the bike **and the rider **more effectively. If each of the 35 seperate little “attentions to detail” saved 2-4 grams then you have a combined enormous drag savings. Many of the very top professional cycling teams, not triathletes, have realized the benefits of rotating the rider forward as steep as possible to enhance the aerodynamics of their posture. That is strictly an aerodynamic/positioning concern- the cycling teams don’t care about the additional benefits of better running off a steep angled bike. The bottom line here is, if you can go steeper, you will want to at the very least retain the capability to do so. It is highly unlikely having the option to go steeper will somehow limti you, but it is highly likely having an inability to go steeper will hinder your performance.
We have the same inseam and I’m rolling on a 54cm P2C and it fits like a glove, so if I were you I’d look into a 54 but if the deal is too good to pass up then I’d say 56 for sure.
FWIW I am 6ft on a 54 and it fits well. I found the 56 a tad too long in both top tube and head tube.
I’m 5’9/5’10 and I ride a 54 P3C frame. However I tried my wife’s 51 frame and I could probably live with that too.
Johnny O is 5’9 and rides a 51, check his blog.
My club mate is 6’ 1/2" and had a 58 but changed it out for a 56.
Based on that I think a 58 is way too big for you. 56 is probably ideal and as someone mentioned, you might even try out a 54. A lot of guys seem to like to ride a size smaller on a TT bike. If you go small then as long as the frame geometry gives you the required drop, you have enough wiggle room between seat position and/or stem to make any necessary adjustment and also you save a bit of weight.
You guys have been a great help. Thank you.