Carbon dropouts - how much wear is normal?

hendo9
hendo9 Posts: 34
edited April 2013 in Road general
Hi all

Just wanted to get some opinions on how much wear is normal on carbon dropouts. I've been riding my new bike for about a month now and yesterday took off the rear wheel to do some tinkering.

I noticed that the serations/teeth on the wheel axle nuts and on the QR skewers had made some fairly substantial indentations in the carbon dropouts. The most pronounced ones were on the inside of the dropouts ie. where the frame contacts the wheel axle nuts.

On the other hand there was hardly any marking on the fork dropouts which are also full carbon.

I'm using shimano rs80 wheels with the supplied shimano QR skewers. I tighten up the QR skewers so that closing them requires firm pressure (leaving a mark in the palm of my hand) but without cranking them down to the point that getting them open is very difficult. I use the same amount of pressure on both the front and rear QRs.

Are these indentations normal? Should I be worried about the long term durability of the dropouts?

Comments

  • JamesFree
    JamesFree Posts: 703
    The main reason why I was put off getting RS80's where the threaded axles (normally found on cheap wheels) as have found they eat into the drop outs
  • Neale1978
    Neale1978 Posts: 484
    Do your dropouts not have an alu clamping area? Do your qr clamped slightly less than what you have been doing it and it should be fine
  • Monty Dog
    Monty Dog Posts: 20,614
    It's important that QRs are kept tight with carbon drop-outs otherwise 'fretting' can erode the material. It's normal to 'lose' the layer of paint/gel-coat as they are quite brittle anyway.
    Make mine an Italian, with Campagnolo on the side..
  • lawrences
    lawrences Posts: 1,011
    The dropouts are solid carbon and incredibly strong so do not worry about crushing them when you tighten your QR skewers. Like monty has said the paint loss/ digging in will occur when they slip so having them too loose will cause more damage than having them tight.
  • Neale1978
    Neale1978 Posts: 484
    Ignore me then, oops

    My forks are carbon with a carbon steerer with an alu clamping area thats all
  • hendo9
    hendo9 Posts: 34
    Thanks all.

    I have been doing them fairly tight as I'm aware that if slipping occurs the teeth would basically act as a drill bit and chew up the carbon.

    However I am surprised by the extent of indentations in the carbon. Almost as if a mold has been taken of the little teeth of the axles.

    I guess I'll keep an eye on it and see how it develops...
  • eskay
    eskay Posts: 57
    Anyone else ever notice that certain skewers seem to creak with carbon forks? I have some that make one hell of a noise but when I changed the for a different make they were silent!
  • hendo9
    hendo9 Posts: 34
    Just found this photo:

    http://www.bikeradar.com/gallery/articl ... 2-30838/15

    Marks look a bit like those in the photo so I guess I'm ok right?
  • Neale1978
    Neale1978 Posts: 484
    Totally normal and the actual clamping area has to be aluminium surely?
  • smidsy
    smidsy Posts: 5,273
    There are bikes with totally carbon drop outs (particularly front forks).
    Yellow is the new Black.
  • lef
    lef Posts: 728
    ive had funda team forks which are full carbon drop outs. They were fine. I was a little nervous about them at first but a year and a half later they are fine. I used to clamp them pretty darn tight otherwise the skewers would creak. Never had full carbon dropouts on the rear but should be no different, though probably more important to clamp tightly due to the forces going through the rear.

Categories