Clamping Carbon Frames

[Grease_Monkey]

I recently got a carbon frame (Spec Stumpjumper FSR) as well as a Thule Velcompact bike rack with clamp style tighteners. The only place the clamp fits on my bike is the down tube. I was warned at the LBS that it is not the best idea to clamp a carbon frame, and if you have to clamp one - do so carefully. Apparently clamping the carbon frame causes damage to the inner layers of carbon, especially when on bumpy roads, which over time weakens the frame in that particular spot.

 

Does anyone here transport their carbon frames on a towbar mounted rack with clamp style fasteners, and if so what are your thoughts on how tight it can be clamped?

 

Is there actually anything to worry about here, or should I just tighten gently and forget about it?

[Captain Fastbastard Mayhem]

Tighten gently, not over-tight. The main problem is if you've got a workstation or hanging bike rack that you clamp the bike to and it hangs from. THAT could be a problem.

 

As for the other clamps to prevent wiggling - no. Not a problem as long as you don't tighten the feck out of it. As an extra security measure to prevent wiggling, get a tie-down and wrap it around the saddle rails, then fasten that to the central anchor point (the part of the rack which the clamp arm attaches to)

 

If it were a problem, there'd be loads more frame failures at the Thule roof-mounted clamp points. 

[BDF]

I have the same bike rack. It works really well for me.

 

As long as you don't over-tighten I can't see that there will be a problem. I use a thickish felt padding directly over the frame where the clamp fits. I also engage the lock which basically puts a clutch on the gears of the tightening mech. That way it cannot wiggle loose over the time you are driving.

 

Make sure the wheels are secured properly. They arm with the clamp is only supposed to hold the bike upright.

 

Again, don't over tighten!

[BDF]

Tighten gently, not over-tight. The main problem is if you've got a workstation or hanging bike rack that you clamp the bike to and it hangs from. THAT could be a problem.

 

As for the other clamps to prevent wiggling - no. Not a problem as long as you don't tighten the feck out of it. As an extra security measure to prevent wiggling, get a tie-down and wrap it around the saddle rails, then fasten that to the central anchor point (the part of the rack which the clamp arm attaches to)

 

If it were a problem, there'd be loads more frame failures at the Thule roof-mounted clamp points. 

Snap.

[andrewde]

Hi. If I can add to this query. I have a Thule tow bar hanging bike rack and my carbon wheels melted on a long drive as I think they were too close to the exhaust. Any suggestion on a bike rack that will avoid this ?

[Pulse]

Thule also sells a carbon frame protector (part no 984) that spreads the load better. I've been using one for a couple of weeks - don't know if it really works. I also put felt under it - at least it helps to limit scratches when clamping.

[Pulse]

Hi. If I can add to this query. I have a Thule tow bar hanging bike rack and my carbon wheels melted on a long drive as I think they were too close to the exhaust. Any suggestion on a bike rack that will avoid this ?

Think that was discussed somewhere on here before; although it related to Fortuners and platform bike racks. If I remember correctly, the solution was to have a downward bend at the end of the exaust, instead of the straight backwards. (If that makes sense...?!)

[andrewde]

Thanks for the advise. So you reckon even a platform bike rack won't help? I drive a landrover so not sure whether exhaust extensions are possible. Was hoping there was something one could wrap against the wheels to protect them. Will have to do some homework.

[Captain Fastbastard Mayhem]

Thanks for the advise. So you reckon even a platform bike rack won't help? I drive a landrover so not sure whether exhaust extensions are possible. Was hoping there was something one could wrap against the wheels to protect them. Will have to do some homework.

You can mount an aluminium blanking plate to the rack to deflect the gases from the vicinity of the wheels... Just a sheet of alu will be fine.

[Pulse]

You can mount an aluminium blanking plate to the rack to deflect the gases from the vicinity of the wheels... Just a sheet of alu will be fine.

Agree with Myles. Small sheet of alu to just divert the hot gasses

[Benjamin]

Thanks for the advise. So you reckon even a platform bike rack won't help? I drive a landrover so not sure whether exhaust extensions are possible. Was hoping there was something one could wrap against the wheels to protect them. Will have to do some homework.

Not so much an exhaust extension, as a rerouting of the exhaust angle. Literally cut the exhaust pipe with a blow torch, about 300 mm inland from the end, and weld on a downward curved piece. Not likely to find a dinkum acccessory piece in the Landy catalogue

[Pulse]

Thanks for the advise. So you reckon even a platform bike rack won't help? I drive a landrover so not sure whether exhaust extensions are possible. Was hoping there was something one could wrap against the wheels to protect them. Will have to do some homework.

If by Landrover tou mean Defender, then it would be no problem, as per Benjamin's post.

Discovery 3/4 will also be easy (look at the exhaust if the 1/2 to see how it angles down)

Range Rovers will be a bit of a different story