I have an old set of Marzocchi Z1 Bombers and have an adaptor to convert its odd sizing mount to a normal IS mount. However the IS adaptor that came on my Clarks M2 caliper does not fit as it wont fit flush against the fork adaptor so I am looking for a IS (fork) to post (caliper) mount. Most seem to be post (fork) to IS (caliper). My question is, can they be used the other way? Alternatively, can you get IS (fork) to Post (caliper) adaptors? (Next step is finding one with a flush edge)

I can’t picture what you mean

pics ?

esp of the marzocchi adaptor – are you sure it isn’t something your caliper can fit directly onto without a second adaptor ?

I had some Z1s, they weren’t I.S. though. I had to knock up an adaptor.

The fork is from the end of the 90s and it came with a double disc mount suitable for forumula disc brakes. Formula mounts while close to the same as IS mounts actually aren’t compatible. So I have an adaptor on the fork that converts it to an IS mount. The only trouble is the adaptor that comes with my caliper, allowing it to use on an IS mount, is curved and therefore the bolts don’t line up with the adaptor on the fork. I will try and get a pic.

This is the adaptor that converts the mount on the fork to IS.
http://s1.postimg.org/73117dhvz/image.jpg

http://webr.ly/userfiles/46714/IMG_1392331863W927852.jpg

This is what you want http://www.chainreactioncycles.com/mobile/shimano-mount-adaptor-front-post-to-is/rp-prod13743

That’s the one I thought it would be. Just need to be sure that the combination of an adaptor on the forks plus an IS to Post mount adaptor won’t push the caliper too far away from the disc. Starting to think that new forks may be an easier solution! However the bombers have just been serviced.

Marzocchi sold a special adapter but most people just used some spacers with a standard adapter to make em fit,
I’ve got some Z1’s on my Five Spot and a couple of spacers about five mm’ish space the adapter out perfectly,
It’s an old problem..
Edit, I used two old 6801 bearings from some Time pedals between the fork mounts and the adapter and they space it out just right
Or get one of these..

Clee cycles do a KCNC one. It’s what I’ve used in the past.

Im not sure I have the same issue, its not necessarily the distance between the mount and the disc but the actual mounting of the caliper itself.

The fork needs an adaptor, to convert it to an IS mount, as per this image:

I am using this adaptor that I got from someone on retrobike:

Howver the post to IS adaptor that came with my disc brake doesnt fit flush against the above adaptor so the bolts won’t line up.

Also, looking at the first image, that caliper has an IS mount but mine is post so the Post to IS adaptor will push the caliper further away surely?

I dumped the marzocchi adapter and just used a normal IS to PM adapter with spacers

Khani, thanks for the pic but I think the issue with the QR20 forks, with the mount too far from the disc, is a different issue. The issue with the original Z1’s with a normal qr skewer mount is that they were launched before IS was put in to place, and the bolts are 48.55mm apart rather than the 51mm of IS, so the issue is in the actual mounting and not spacing to the disc.

I think I have found some useful info in the following link and looks like I should be able to run both adaptors as per this image. I just need to find a Post to IS adaptor that sits flush with the other adaptor to be able to bolt them together:

http://www.pinkbike.com/forum/listcomments/?threadid=113683