Fork Brake Mounts: IS vs Boxxer

[Derek Yates]

Ok I'm sure I used to know this but I can't remember. Can someone tell me if there is a way of using an adaptor to mount a 7" Hope M4 Boxxer mount caliper to an 8" Rotor on an IS fork (ie 888)?? I'd prefer to not have to buy a new caliper half (I assume that you can't get these anymore anyway).

Another Curly one. Is there ANY way of mounting the above brake on an 06 66RC2X with an 8" rotor? This fork uses direct Post mount. I'm assuming not but maybe someone does something creative?

Any clues from people who know would be awesome.

Cheers,

Derek

 

[Registered Nutcase]

you can still buy the halfs, however they are very expensive.

i needed a new caliper half for my forks and i got the half from CRC it was $70+shipping compared to around $200 in australia.

as for the rest of your question no idea mate

 

[Daver]

Ok I'm sure I used to know this but I can't remember. Can someone tell me if there is a way of using an adaptor to mount a 7" Hope M4 Boxxer mount caliper to an 8" Rotor on an IS fork (ie 888)?? I'd prefer to not have to buy a new caliper half (I assume that you can't get these anymore anyway).

Another Curly one. Is there ANY way of mounting the above brake on an 06 66RC2X with an 8" rotor? This fork uses direct Post mount. I'm assuming not but maybe someone does something creative?

Any clues from people who know would be awesome.

Cheers,

Derek

OK. Quick question- are you sure its a 7" (185mm) rotor? When you run M4s on boxxers using the boxxer specific number 6 caliper you need the 8" (205mm) rotor.

Fitting a boxxer caliper to an 888 can be done very easily. A boxxer caliper needs roughly 3mm ground off it (around the holes where it mounts to the fork) and it will line up perfectly with the marzocchi 20mm IS mount if you run a 1" smaller rotor. If you are desperate to run the same size rotor as you were on the boxxer you'll need a step up adapter. With this setup you won't need to piss around with excessive amounts of spacers.

Secondly, the same setup will work on the 66 with post mounts, but you will need about 6mm in total removed from the caliper (again, from the holes). Then you will need the IS to manitou Hope adapter, and it will bolt straight on. With this setup you'll need the same size rotor as you ran on the boxxer.

 

[Derek Yates]

Brakes

Hey Daver,

Cheers for the good info. It's definately a 7" rotor up front as that's all hope used to offer when I got the brakes (with an alloy splined castle adaptor for the Bulb hub). This is why I'd prefer to keep the same setup if possible.

So if I get the IS to post mount adaptor, file the caliper 6mm (shudder) and run the existing 7" rotor on a 66RC2X I should be sweet?

The front Caliper is a G1 M4 so I'll check it out and see how much material I have to play with.

Cheers,

Derek

OK. Quick question- are you sure its a 7" (185mm) rotor? When you run M4s on boxxers using the boxxer specific number 6 caliper you need the 8" (205mm) rotor.

Fitting a boxxer caliper to an 888 can be done very easily. A boxxer caliper needs roughly 3mm ground off it (around the holes where it mounts to the fork) and it will line up perfectly with the marzocchi 20mm IS mount if you run a 1" smaller rotor. If you are desperate to run the same size rotor as you were on the boxxer you'll need a step up adapter. With this setup you won't need to piss around with excessive amounts of spacers.

Secondly, the same setup will work on the 66 with post mounts, but you will need about 6mm in total removed from the caliper (again, from the holes). Then you will need the IS to manitou Hope adapter, and it will bolt straight on. With this setup you'll need the same size rotor as you ran on the boxxer.