TT's vs Carbon

BBH

Sorry Guys,

Quick question - Do you use your summer carbon beauty on the turbo? Is it ok or is the frame likely to damage during use?

Reason I ask is 'cause I am using my winter hack for daily commute and really dont want to be changing the tyre twice daily to also use it on the TT (although I can see the advantage that I'd get quick at doing it!).

Many Thanks!

bigpikle

yep - carbon on the TT

jonmack

I use my Team Carbon on the turbo.

ride_whenever

Buy an old steel clunker and replicate your position... Purely to save time on the days it is clear and dry!

ozzzyosborn206

i would never do a hard set on a carbon bike on a turbo, i know a few people who have cracked frames from doing it, when your on the turbo look how much the bottom bracket moves side to side and twists mainly when you stand up and put the power down, carbon doesn't like that kind of movement, and for the sake of a cheap as chips turbo wheel it seems a no brainer to me

SteveR_100Milers

ozzzyosborn206 wrote:

i would never do a hard set on a carbon bike on a turbo, i know a few people who have cracked frames from doing it, when your on the turbo look how much the bottom bracket moves side to side and twists mainly when you stand up and put the power down, carbon doesn't like that kind of movement, and for the sake of a cheap as chips turbo wheel it seems a no brainer to me

This has been debated to death before - the forces on the frame when riding on the road are similar, and to be honest, assuming it's not because you fell of it whilst attached to it, if you can generate enough force to crack a CF frame on a turbo then we should have hard about you by now

to the OP I use my TT bike on the turbo in both the winter and summer (as it doubles as a stand). The biggest risk is corrosion of metallic parts due to sweating over it, which is prevented by judicious placement of a towel.

cougie

If a carbon frame can withstand Hoy etc - it can cope with our puny efforts on a turbo.

Just dont let your sweat corrode the metalbits.

Chiggy

ride_whenever wrote:

Buy an old steel clunker and replicate your position... Purely to save time on the days it is clear and dry!

Yes. Something with the same measurements as your road bike and leave it on the turbo. It doesn't have to have brakes. It doesn't really need a front mech or a small chainring.

The roller weight takes care of inertia and the turbo's loading system takes care of the bike's aerodynamics.

Tom Butcher

Must admit I'm not 100% convinced carbon is OK on the turbo, just 99%, but I do use my carbon TT bike on it and it hasn't broken so far.

However if I had a hack bike that wasn't in regular winter use I'd use that as much as for the issue of wrecking the kit with sweat.

edit - I'm not doing out of the saddle sprinting on it though

Alex_Simmons/RST

ozzzyosborn206 wrote:

i would never do a hard set on a carbon bike on a turbo, i know a few people who have cracked frames from doing it, when your on the turbo look how much the bottom bracket moves side to side and twists mainly when you stand up and put the power down, carbon doesn't like that kind of movement, and for the sake of a cheap as chips turbo wheel it seems a no brainer to me

If a frame cracks on a turbo, either:
- it was not properly installed on the trainer
- the frame was already damaged
- it was of exceptionally poor quality to start with

the forces through a bike out on the road are far more than you'll ever do on a turbo.

Pokerface

Alex_Simmons/RST wrote:

ozzzyosborn206 wrote:

i would never do a hard set on a carbon bike on a turbo, i know a few people who have cracked frames from doing it, when your on the turbo look how much the bottom bracket moves side to side and twists mainly when you stand up and put the power down, carbon doesn't like that kind of movement, and for the sake of a cheap as chips turbo wheel it seems a no brainer to me

If a frame cracks on a turbo, either:
- it was not properly installed on the trainer
- the frame was already damaged
- it was of exceptionally poor quality to start with

the forces through a bike out on the road are far more than you'll ever do on a turbo.

I agree with you on this - however - if he is talking about efforts where you are out of the saddle (on the turbo), does this add extra stress to the frame? On the road, the rear triangle isn't fixed, so the force moves to the wheels and the road. On the turbo it looks like the frame absorbs it all?

ut_och_cykla

The turbo itself flexes too - I would guess this takes up much of the forces that would normally go into teh bike movement. A German bike mag did a big scientific test of the issue some years ago and concluded that bikes were subject to more stress in a road race than a mad man on a turbo - apart from perhaps really top end (pro level) sprint repeats....

ozzzyosborn206

I agree with you on this - however - if he is talking about efforts where you are out of the saddle (on the turbo), does this add extra stress to the frame? On the road, the rear triangle isn't fixed, so the force moves to the wheels and the road. On the turbo it looks like the frame absorbs it all?[/quote]

thats what i am getting at, a turbo my flex a little but when you sprint on the road your bike moves side to side which doesn't happen on a turbo so i do not agree that the forces are less than on the road, all you have to do is look at the bottom bracket and you will see, as i said i know two people who have cracked carbon frames on the turbo, one of which was a cannondale slice so you would expect good workmanship. But go ahead and use your carbon pride and joy on the turbo but don't say i didn't tell you

jonmack

I don't do standing power efforts on mine, but at 65kg with spindly little spider legs I doubt I could do much damage to it anyway.

I'll carry on using mine on the turbo, if it breaks then I'll buy a new frame, simple. That's what credit cards are for... right?

neeb

If you think about it, when you are on the road the side-to-side rocking movement of the bike when you are out of the saddle is pretty much irrelevant - it's certainly not absorbing any significant amount of energy. It's just allowing you to distribute your weight better so that you can put even more stress through the frame! You can't do that on the turbo to the same extent (the bike remains upright), so the stress will actually be less.

The only possible difference on the road (compared to the turbo) in terms of reducing stress through the frame is wheel and tyre flex. Wheels are pretty stiff however - I'm sure my turbo frame flexes a lot more than my wheels.

Alex_Simmons/RST

I supervise about 80 rider turbo sessions per week on all sorts of bikes. The turbos flex more than the bikes do. I see every sort of bike from old steel bikes to Cervelo P4s.

Out of saddle sprints/starts are not really recommended anyway since tyre slippage will always be an issue.

BBH

Thanks for the replies guys!

Has given me plenty to think about! :oops:

Think I will start with the carbon and see how it goes, my main worry was about out of seat efforts as I was concerned about the stresses through the frame, but I think I will have to limit these for now!!

I always thought buying a new wheel and cassette for the TT would be fairly expensive, how can you get them for 'cheap as chips'?

Pokerface

BBH wrote:

always thought buying a new wheel and cassette for the TT would be fairly expensive, how can you get them for 'cheap as chips'?

I was in Decathlon today - and they were selling new rear wheels for £35. Add to that a cheap cassette (probably also around £35) and you have a turbo wheel for £70.

And that is NEW. Look on eBay and you can find used older wheels for less.

BBH

Many Thanks for that pokerface!

Thats not bad at all, I will investigate further