"The 33"-Road Bike Racing - TT bike sizing...

I hopped on a TT bike at my LBS today - a $3500 Cervelo model - and much to my surprise it seemed to fit me very well. That struck me as a bit odd, because this was a 54cm bike, and I ride a 56cm road bike (my Ibis is actually 57mm). If anything this bike might have been a touch too large, but my impression was that I would be able to dial it in with an allen wrench in about 15 mins. Nice bike by the way.

Is that typical? Would a 56cm road bike guy often fit on a 54cm TT bike? Or does that vary completely between manufacturers.

Finally, if I haul this rig out on the group rides I do am I condemning myself to Fred Hell? I don't know if I would actually do it, but once I buy the thing I'd like to get very comfortable with the bike's handling?

Slap a pair of Zipps on that TT bike and it would be one very fast bicycle. But that TT position is going to take a lot of training to get used to.

Is that typical? Would a 56cm road bike guy often fit on a 54cm TT bike? Or does that vary completely between manufacturers.
The way Cervelo sizes their bikes, most people end up one size smaller on a Cervelo than most other brands. Within Cervelo, though, if the 54 cm TT bike is right for you, you'ld probably end up on a 54 cm road bike as well.

Finally, if I haul this rig out on the group rides I do am I condemning myself to Fred Hell? I don't know if I would actually do it, but once I buy the thing I'd like to get very comfortable with the bike's handling?

Hmm... new TT rider on aerobars in group ride...

No dice, Pcaddy.

Like you, my coworker went from a 56 Cannondale to a 54 Cervelo Tri bike. I don't know if it's because of Cervelo's sizing, or if it's because tri/tt bikes fit differently, seing as though you're so much farther forward on those frames.

As far as where to ride it? Personally I wouldn't want to take a bike like that on group rides, but my coworker has been using his Cervelo to commute to work and back 3 times a week to get used to riding in the new position.

People often ride smaller framed TT rigs than their road bikes.

2cm smaller is about right for a TT bike. My TT bike (a Cervelo) is actually the same size as my Tarmac, but the measurements are different, and they're both dialed in right..

People often ride smaller framed TT rigs than their road bikes.

+1 my Time is a 53, my Cervelo TT bike is a 51. don't take it on a group ride. do go out on your own to work on the handling and get comfortable on it

just tell them you are practicing for a TTT.

I wouldn't dream of taking a TT bike on a group ride until I had many solo hours to get comfortable with the bike. Not in a zillion years. I won't even attempt it until I'm smooth and confident on the bike. Which won't be until I purchase such a bicycle. Which is still in the hemming and hawing pre-fifteen threads on BF about it stage.

This is only a pre-Pcad's Thinking About Buying a TT Bike Thread. But the Cervelos were nice bikes. Whatever. Like my LBS shop pal Rich said, 'once you get over $3K, none of it's crap.'

TT bikes are welcome on the group rides that I do, although it is a small group of usually 6-12 riders. What is generally not welcome is for riders to ride in the aero position when they are not on the front. I know nothing about sizing TT bikes, but I have read in various forums that people often ride a TT bike 1 or 2 cm smaller than their road bike. I am sure that Cervelo is a killer bike. I am looking forward to many threads contemplating its purchase.

http://www.cervelo.com/bikes.aspx?bike=P2C2007

It's the P2C. The good news is the MSRP on the 2007 model is down to $3K even from $3500 last year (I may have been looking at a 2006 bike). Hopefully I can buy this bike for $2600 or so brand new. Cdale is introducing a new all carbon bike too. But there were fit adjustability aspects of the Cervelo that appealed to me. Also looked mega-aero and had a nice component mix. A P2C with Zipp 404's could even make Pcad a little faster.

I would get it in Blow Me Blue of course.

Just make sure you get fitted for the Cervelo properly. The angles don't change through the sizes which generally isn't too big a problem, but something to be aware of. Second thing is figuring out your position before you buy (on a bike not guestimating on the forum). I ride a 54cm top tube road bike (C-dale) but ended up on TT rig with a 50cm TT, and a scary amount of saddle to bar drop.

Right now I'm on an old 58cm Trek road bike(because it was given to me, it's probably a bit big). I should probably be on a 56cm. I bought a new TT bike for triathlons and ended up on a 52cm QR Kilo. Its a nice bike and fits real good surprisingly. The 54 Cervelo was a bit too big for me. I think I have long legs and a short torso. Just be sure you get a good fit before you buy.

I ride a 56cm Cannondale Six13, fits me like a glove. I'm looking at a used 54cm Slice Six13 style TT bike. In the shop the 54cm TT bikes from Cervelo and Cdale really did seem about right, but it's hard to know since I've not really had the experience I have on a road bike. I may just buy this 54cm bike used (the price is certainly right) and see if I can get it to fit. If not I can re-sell it. I can buy this bike for $2200 with cheesy wheels. The new ones with Zipps retail for $5500, even with a discount, after tax I'd be laying out close to $5K.

No wonder so much bike schwag gets purchased on eBay.

I'm 5'11", longish legs, short torso. The Cdale TT bike has a short 53.5cm top tube. But that might not matter so much on a TT bike. My concern would be getting the handlebars high enough to get comfy on the bike given the small frame size.

What are the odds this sizing will work out for me? Anybody want to hazard a guess based on all that? I'd bet it would work...

It actually sounds just about right to me.

Well I don't think "comfy" is really what to be expected. I know 'dale generally reccomends going a size down for their TT bikes (so the 54cm fits), though given your geriatric old man status I'd be concerned with your flexability, but that's something a steep mtb stem could solve.

People typically ride ~1 cm shorter TT in a time trial bike, and a slightly shorter stem, if your not used to riding a TT bike you wont really know what size feels right. much like a 6' tall person used to riding a mtn bike might thing a 54cm road bike is comfortable when it probably isnt.

I would pay attention to Top tube lengths as bike sizes typically talk about the seat tube.

My advice would be to size by the top tube. I ride a 58 top tube on the road, but a 56 on my TT bike. I would have even preferred a 54 to really get my seat in a legal position.

Well I don't think "comfy" is really what to be expected. I know 'dale generally reccomends going a size down for their TT bikes (so the 54cm fits), though given your geriatric old man status I'd be concerned with your flexability, but that's something a steep mtb stem could solve.

Yeah, but at least I can still spell right.

Yep, that's a lot of votes for the 54cm TT size all things considered. Both bikes in the shop (the Cervelo and the Cdale) felt about right in that size. I think I'll give it a whirl.

I'm 63-64cm with road bikes, and I'm on a 61cm TT bike

Hmm... new TT rider on aerobars in group ride...

No dice, Pcaddy.

correct.

Damn the drunken posting....

old man.

my boss rides a 60cm Cannondale and rides a 54cm cannondale TT bike.

I also size down on my TT bike. I ride a 54 Trek but my road rig is a custom 59TT x 52ST

You can drop a size, which seems to be the norm, but I didn't on mine to get stretched out.

http://www.chriscollins.org/tt_pics/DSC00513.JPG

That lets me sit farther forward in the saddle, and move to the front of the aero bars (im actually sitting a bit too far back in this pic).

Thus, keeping the size lets me both get in a position to both produce power (I actually have higher power on my TT bike than my road bike), and get aero with arms/back/etc.

just tell them you are practicing for a TTT.

TTT?

PM me and I can give you all sorts of advice on the Cervelo sizing. but nutshell, 54 should be correct.

TTT?
Team
Time
Trial

DrW - how tall are you/what size do you ride?

Pcaddy - how tall are you?

Team
Time
Trial


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