Carbon Bikes and Roof Bars

Fen Grinder

Hi,
Just a quicky. I am currently in the market for a new bike that will probably end up being a Felt 1, and currently use a Thule 591 Pro-Ride roof bar system. I recently read on an obscure forum that lightweight carbon frames should not be clamped in this manor, i.e clamped on the down tube in jaws that adjust, squeezing the top and bottom of the tube.

Any Advice / Opinion.

Stuart

kevin bannister

Hi,

I saw one of these at the cycle show last autumn and was impressed, so bought one and have been very impressed with it in actual use. The frame doesn't get touched at all and its very easy to change to different size wheels which is great, with mountain, road and bmx bikes to lug around. It locks to the roof bars and the mechanism locks to the bike and also includes a cable lock as well.

The rack is called an INNO Ina388 tire hold and is available from http://www.roofbox.co.uk

Kev

mwalters

The general explanation for the "no clamping" rule is that carbon fibre is only very strong if the forces being applied are where the design/layup expects. Clamps that squeeze the tubes risk crushing them if they are done up too tightly and this can be quite easy to do if you're not careful. Having said that I have a Mont Blanc carrier that uses wheel straps and a clamp on the down tube that I use regularly for short local distances. The straps hold the bike in the carrier and I set the clamp to just about touch the frame when it's fully closed - just enough to stop it moving from side to side.

Over the half term week I took the bike (Giant Defy Advanced) away on a longer, motorway, run using the same carrier. Just to be sure I used a short section of plastic downpipe - the sort you use for drainpipes - which I cut along its length to allow it to be spread and placed around the bike down tube. I wrapped the tube in bubblewrap, put the pipe around it, and then clamped around this, just a little tighter than I would have without the pipe, to hold the whole lot in place. Not sure it was really necessary but it made me feel better!

Mark

wishitwasallflat

If your fork has alloy drops outs or manufacturers say its ok these are nice -


http://www.skidrive.co.uk/cycle/product ... tAod3wUAnA

shadow4532

personally i would carry on using your thule rack. iv seen the damage that people have sustained by forgetting that the bike is on the roof and very rarely is the bike damaged but the rack and car have been.

careful

I recently posted on here that with my Bianchi Infinito in a rack like yours I stupidly forgot and ran into a height restriction bar at a car park entrance. The rack was written off (the gutter channel bent and the rack's clamp jaws sheared). The rear wheel (Fulcrum 3) got pushed down putting a deep dent in the car roof. The front brake took the initial impact, bending one arm of ther caliper. With all this mayhem, nether the wheels or the frame was damaged at all. Not even a scratch despite very close inspection of the down tube, steerer etc. Prophets of doom will say that there could be latent cracking etc. I have done 300 miles on the bike since the incident, including lots of pot-holes and cattle grids - still not a trace of damage to the frame. I would now have absolutely no worry about the risk from clamping, but I will try to remember that my bike is on the roof next time I see a height retriction.

Monty Dog

You'll find that exclusion terms on roofracks are to protect makers from strong-arm numpties who don't consider the consequence of their actions but check out the following link for concerns about over-tightening your roofrack clamp:

http://www.youtube.com/watch?v=SDVpRSNtcPQ

shadow4532

And this one.
http://www.youtube.com/watch?NR=1&v=xre ... =endscreen