marzocchi i.s. mount forks won`t fit, whats going on?

Hi,
Ive just fitted a set of 2005 Marzocchi z1 bombers to my Bfe, and theyve got an i.s. brake mount, as have my old style Hope m4 brakes. The forks are 20mm bolt through, and my wheel is a Mavic 721 on a Hope pro2 with 20mm adaptors. The i.s. mount on the Marzocchi fork is about 10mm too far away from the caliper when it sits on the disc, are they all like this? Ive fabricated an adaptor out of an old i.s. to p.m adaptor that I had lying about but its not very pretty. Ive checked everything to make sure Im not being stupid here- the wheel sits nicely central in the fork, the disc is fitted right on the wheel, but the threads on the fork are miles away from the threads on the caliper, im using extra long bolts through my adaptor to make it reach. I probably am being stupid, and just havent spotted my obvious mistake yet haha, but Ive been out and ridden it and it all looks right and it feels great, even off drops. If all Marzocchis of this vintage are like this, does anybody make an adaptor?

Some 20mm through axle Marzochhi’s from this era had washers/spacers to space them out
I have some DJ’s on my tandem which have these washers/spacers in.
I got mine from Marzochhi/windwave after contacting them, but I am sure your home made one’s will be fine.

You can get a specific adaptor for this, assuming you want a 200mm rotor

It’s a variant of the IS mount (I think maybe they called it IS 200 ??)

I think this might be it – see how the holes seem to be offset ?

I have had to space marzocchi’s before. I have used caliper shims plus full range of shimano brake adapter.

Never as much as 10mm though!

If all Marzocchis of this vintage are like this, does anybody make an adaptor?

I’ve a pair of bolt-through 2004 Z1 FRs which are like that, I think it was a 20mm variant on the IS. Another pair of QR FRs I have are “normal” IS.

I get round it by using a 2.5mm spacer on the disk and a couple of thick washers on the fork. Scaredypant’s link looks like it maybe would do the trick (assuming your brakes are PM), the ad does mention different adaptors for the QR and 20mm versions.

You can just about see the silver spacers in this pic. Also has an adapter to run a 203mm disc

excuse the messy shed, the tandem is at the back under loads of …
It doesn’t get out much due to the kids.

hantsnightrider- youve obviously had the same issue as me, and i agree with you that my spacer will be fine but id like something that looked smarter and more “factory” so I will do as you did and contact Marzocchi/Windwave and ask. I assume this is only an issue with certain forks and 20mm bolt throughs.

scaredypants- the issue i have is i.s. to i.s., rather than i.s. to p.m. my bolts all line up fine, theres just a big fresh air gap between the fork leg and the caliper!

garage-dweller- ive never had to space marzocchis before either- one of my kids has dirt jumper 3s on his bike and the other has 03 z1 freerides, both i.s. mount and qr fitting, no issues at all. Its like the spacer on the 20mm Hope adaptor takes the fork leg too far away from the disc, but the wheel fits on the fork perfect and perfectly central. I think hantsnightrider has this anomally sussed, so Ill follow his lead.

Thanks for helping, folks.

hantsnightrider- thanks for the picture. Thats EXACTLY what im talking about!

It must be over 8 years ago I had this problem, hopefully someone at windwave will remember.
good luck

As with all IS mount calipers on IS forks, they also needed the thin spacer washers to get perfect alignment

Could you flip the adaptor around, so it steps the other way?

How about this ? I’ve a feeling their +20 description might not be correct – looks nice & broad

No need for an adapter, space it out as per the photo above – the 20mm IS forks came with 2 big washers to do this.

I have a envelope full of marz IS brake mounts (3 I think), these may be of some use to you. Could post them if you like.

Simone