So I have marzocchi 66’s with post mount. Got myself a 180mm disk with some fairly old 4 pot hopes.
Turns out It seem impossible to use the 180mm disk, also the mount I have leaves the calliper overlapping the disk. So I figure I need a 203mm disk, but then what mount?

Below are pictures of the problem.
I know these aren’t the correct bolts to use, just an attempt to align everything.

Any help would be much appreciated. Cheers, Craig.

you have apotmount fork and a IS caliper
It looks like you are using a IS [ to the forks] with post mount to the caliper inverted so it wont work – your pics are small I cannot really tell tbh
You need a Post mount fork to IS caliper- I dont think they do this

http://www.hopetech.com/webtop/modules/_repository/documents/HopeBrakemounts2012.pdf
dont know if anyone else does

That brake adaptor is wrong. You need to adapt an IS brake to a Post mount fork, the adaptor you have does the opposite.

you can get mounts the other way round but can’t remember where from. One of the small make that does CNC stuff I think.

I’m fairly confident that you can’t fit that caliper to that fork. The Hope IS to PM adaptor does not work with Marzocchi forks.

I had figured the mount was wrong, just used it to illustrate the problem. The thumbnails are links to the full scale images.

From what I see, the correct one is not on the hope site.

you could try one of these from KCNC. It seems to work on most (but not all) forks. For the price it’s worth a try and it doesn’t involve an increase in disc size. That looks like you have completely the wrong adaptor at present.

Here’s a pic of one on my bike (180mm hope brake & disc) if that helps.

That looks promising. I think it will work for a 203mm as that should give me more clearance. Have them on their site so.

Anyone fancy swapping a 203mm for a 180mm ?

You shouldn’t need to go up a disc size, unless you want to. That’s the point of that adaptor

Well as it states, it wont work for all callipers/mounts. From my side, it’s clear that it wont work, as you can’t place the calliper where it needs to be without the fork mount being in the way. I have tried to depict this above.

Hey it’s your brake and fork. Go for your life…. Was only trying to help.

as bigG said that’s a 180mm caliper on a 180mm disc.

if you have a 180mm caliper it will work with a 180mm disc. IF you need to use a 203mm disc and have a 180mm caliper then you will need a different adapter or use the above adapter with a +20mm post mount to post mount adapter to push it out further.

Na, I appreciate the help, really do. Been building this bike for 2 months on a budget and this is the last thing left. Just don’t think its possible to run a 180mm with this particular set up. It’s hard to show why I think that in pictures.

Kcnc have products for running 203mm disks which would give me more clearance?
Getting a larger disk is no problem as i’ll just sell this one, plus get some more power I guess.
If I use the kcnc 203mm mount with a 203mm disk will be a solution? (shown on bigG’s link)

I cn see why bigG is getting frustrated.

tbh I think you are just holding your caliper at the wrong angle. If it’s a 180mm IS caliper than the bolt holes will be in the same position as bigGs above. Yes there may be some extra bulk on some calipers which means the adapter won’t fit but I would give it a go and see.

PS if you have a 180mm caliper then you probably need the 160mm adapter. Why not order both as you have 7 days to send it back?

OK, seems like the best thing to do is just try these adapters. Cheers for the help.