I am riding a Trek 6500 dating 2001-2002. The dealer at that said the bike was adapted for using disc brakes. Now I'm looking to mount disc brakes and I am able to spot the international mounting structure on the RockShox Fork. I didn't see however an International mount structure for the rear caliper. The only thing I can spot are two small holes in the lying rear fork. Is this the place to mount the rear caliper and if yes, which kind of adapter do I need?

Frederik

Assume you're refering to the left chainstay.

IIRC those are the standard Hayes rear mount (same as that on my '02 Trek 8000) on which rear Hayes mag calipers would bolt directly.

There used to be adaptors which converts the Hayes Rear Mount to International Standard like this:A2Z.

There are universal bolt-on disc brake mounts which may be a better alternative, example: retrofit.

You can pick up the adapter on ebay for 25 or so dollars. Are those two holes 51mm apart?

FrankH's links are helpful. I had this on my trek 7000. It is the 23mm parallel disc mount. Hope down to the LBS and they should have one cheaper than 25. I got mine for something like 15. Ebay too has some, just look around. As far as universal bolt-on disc brake mounts, i do not feel that they are needed and cost a bit more too. Mine works just as good as on my other system that is the standard mount. No worries there.

It's indeed the Hayes Rear Mount. Adapter acn be found on ebay for $13. Unfortunately not shipping to Europe, so will be hopping to the LBS; now with the details of what he needs to get...

Thanks

Frederik