Cervelo and BH sizing question

[Velo Dude]

I have been to two dealers to check my fit on a BH G5, and two dealers to check my fit on a Cervelo R3 SL.

Both BH dealers said a 56 BH frame was best, and both Cervelo dealers said a 58 Cervelo frame was best.

The 56 BH G5 has a 55.7cm (effective) TT, while the 58 Cervelo has a 58cm (effective) TT.

Can these both be right?

(Note: I thought a 56cm Cervelo would fit me best, because the TT is 56.5cm. I am slightly under 5'11").

 

[sappie]

The Cervelo frame sizing is very well thought-out and quite different from other companies' sizing methodology. See the technical presentation on sizing on the Cervelo website.

 

[karlboss]

Though cervelo sizing may be well thought out it doesn't mean the dealer you saw has a clue. I'm going to cop criticism for this but the toptube is the vital measurement in finding which stock frame from a given brand works for you, to a lesser extent headtube length if you need particular short or long. As seatube length can be altered, but altering the length via the stem results in steering differences. Ride both and pick the size you think works best for you, maybe a longer top tube and shorter stem will work for you or vice versa.

 

[Velo Dude]

The Cervelo frame sizing is very well thought-out and quite different from other companies' sizing methodology.

I know that's true, but of course it doesn't mean the right size for me is a 58.

One reason I ask is because I've looked at many posts on the internet talking about Cervelo sizing, and it seems like everyone who is my height rides a 56, and guys taller then me (like 6'1" or 6'2") ride a 58. I'm 5'11".

Here is an example: "Just for perspective I am 6' 1/2" and ride a 58 R3 SL and it feels great. I could have fit a 56 but like the longer headtube on the 58."

He's over 6 feet tall and he could have ridden a 56? I'm 5'11" and a 56 is too small? I know different body proportions can make a difference, but I think my body proportions are pretty average. It's confusing to me how one bike with a 55.7cm TT can fit me while another with a 56.5cm TT (a 56 Cervelo) is too small.

I'm not saying the 58 is not the right size for me, I just want to understand why.

 

[Velo Dude]

Though cervelo sizing may be well thought out it doesn't mean the dealer you saw has a clue. I'm going to cop criticism for this but the toptube is the vital measurement in finding which stock frame from a given brand works for you, to a lesser extent headtube length if you need particular short or long. As seatube length can be altered, but altering the length via the stem results in steering differences. Ride both and pick the size you think works best for you, maybe a longer top tube and shorter stem will work for you or vice versa.

Is it possible that the optimum fit for me is somewhere in between the 56.5 and the 58, and that I'm going to be compromising on ride characteristics either way I go?

If so what is better, longer TT and shorter stem, or shorter TT and longer stem?

 

[lagartija]

Is it possible that the optimum fit for me is somewhere in between the 56.5 and the 58, and that I'm going to be compromising on ride characteristics either way I go?

If so what is better, longer TT and shorter stem, or shorter TT and longer stem?

VD , i can relate , i ride different sizes depending on manufacturer , but i do presently own 2 cervelos........among some other toys....haha

i found cervelo absolutely the hardest bike to fit, the geometry and tube angles change for every frame size.......i would suggest doing a self fit on line, find a site with a fitting program and follow it carefully, you will need a partner , and i would suggest doing it 2 or 3 times and average out the results..........if you have the coin and if its available near you pay for a retul fit session, or at least go through the BG fit system.......it makes sense if you plan on spending several thousand on a new bike......
also it just occurred to me , cervelo is notorious for toe overlap , its really only effective at very slow speeds but its something to consider...
well at 5'11" i personally think your at most a 56.....i do love the bike, cervelo is probably the best overall bike i have ever ridden, they are not pretty , and there customer service is real crap...........but damn its a nice ride.....good luck..................

 

[Bobby700c]

Top tube length isn't a definitive guide. Seat tube angle also has to be taken into account, i.e. if two bikes have the same top tube length but different angles, the one with the steeper seat tube is effectively larger, assuming that the saddle is set in the same place relative to the bottom bracket. Hence the 'reach' measurement that is quoted by Cervelo, and I believe a few others, which is the horizontal measurement from the BB to the head tube.

 

[karlboss]

If I could achieve my position on two different frame sizes, I'd go for the smaller one. Smaller frames are stiffer and lighter and a longer stem looks better.

 

[Laszlo]

VD , i can relate , i ride different sizes depending on manufacturer , but i do presently own 2 cervelos........among some other toys....haha

i found cervelo absolutely the hardest bike to fit, the geometry and tube angles change for every frame size.......i would suggest doing a self fit on line, find a site with a fitting program and follow it carefully, you will need a partner , and i would suggest doing it 2 or 3 times and average out the results..........if you have the coin and if its available near you pay for a retul fit session, or at least go through the BG fit system.......it makes sense if you plan on spending several thousand on a new bike......
also it just occurred to me , cervelo is notorious for toe overlap , its really only effective at very slow speeds but its something to consider...
well at 5'11" i personally think your at most a 56.....i do love the bike, cervelo is probably the best overall bike i have ever ridden, they are not pretty , and there customer service is real crap...........but damn its a nice ride.....good luck..................

I have to agree with just about everything you've said about cervelo- I have major toe overlap, no trackstands for me, very stiff for climbing but the aluminum frame is a very harsh ride on cracked roads.

 

[Tangled Tango]

I own an 56cm Cervelo R3, I´m 5´10¨ and it´s a great fit for me. I have long arms and long legs, but it´s the top tube that is most crucial and the 56.5cm gives me a nice aero position while being the most comfortable bike I´ve ever owned.

If you can test ride and compare both bikes in both 56cm and 58cm sizes, the decision size-wise should be relatively easy. Chosing which bike will have more to do with position and comfort.

Good luck.