Carbon Fibre and Bike Carriers

[Gormenghast]

First post on this forum. Hope I've posted in the right part. Here goes............ I used to carry my aluminium frame road bike on my car roof rack with one of those carriers that clamps the down tube thereby holding it upright. The wheels are strapped to a kind of gutter arrangement. Now I have a carbon fibre frame (last one got nicked and insurance replaced it with present) In the manual it advises clamping it into a workstand via the seat post not the frame. Would the same apply to my bike carrier. If so, how do others get on, or is it safe to continue with carrier as before.

TIA any replies.

 

[sogood]

Clamp at your own risk obviously.

 

[peterlip]

Is carbon really that fragile that you can't clamp it???
I've got a tow bar mounted rack, which you clamp your top tube with. I'm thinking about "upgrading" the alloy bike to some carbon. Does that mean I need to think about another way to transport??

 

[benkoostra]

If they ride carbon frames on the cobbles of northern France, I think your bike rack shouldn't present too much of a problem...

 

[TheDarkLord]

If they ride carbon frames on the cobbles of northern France, I think your bike rack shouldn't present too much of a problem...

Many carbon wheels in P-R did develop problems though.

 

[benkoostra]

Many carbon wheels in P-R did develop problems though.

He's not clamping to a wheel...

 

[TheDarkLord]

He's not clamping to a wheel...

I was commenting on your post about riding carbon bikes on cobbles. I don't have any experience with the material to comment on the OP's question.

 

[Powerful Pete]

If at all possible I would avoid clamping a CF road bike tube. I would suggest changing over to a bike carrier where you must take off the front wheel and use a quick release lever in the bike carrier itself to secure the fork.

 

[peterlip]

If at all possible I would avoid clamping a CF road bike tube. I would suggest changing over to a bike carrier where you must take off the front wheel and use a quick release lever in the bike carrier itself to secure the fork.

So, are we talking cracking the tube if I clamp it?
Has anyone had a bad experience clamping a tube? Is this real, or an urban myth?

 

[TheDarkLord]

So, are we talking cracking the tube if I clamp it?
Has anyone had a bad experience clamping a tube? Is this real, or an urban myth?

I would guess that it depends on how the material is woven, and how much force/torque is applied to the tube through the clamp. The fibers have no strengh to withstand lateral forces (note how carbon wheels crumble when too much lateral force is applied - e.g. the Burghardt incident in last years Tour de France http://www.youtube.com/watch?v=9JGFn5s38uo). Obviously, in a tube, there are many layers of fiber that are cross-woven to give it strength, but I don't know what level of forces it is designed to withstand.

 

[Capisce]

I've had a similar rack for years and been clamping my CF frame without problems. It's not like your applying hellish amounts of force in these clamps.