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Post to IS Disc brake adapter problems

EarlofBarnetEarlofBarnet Posts: 673
edited December 2010 in MTB workshop & tech
I've just got an XTR front disc brake with an IS mount that I'm wanting to fit to my Post mount Marzocchi forks. I've got an adapter which seems to be a standard shape across a few companies (bike fridge etc). One side fits fine and has a nice flat edge for the bolt to sit against. The other end is curved and the bolt won't sit against it flat. Does anyone have any experience of this problem?

Adapter looks like this:

Type3IStoPostF180.jpg

The end I'm having problems with is highlighted in Red.

Posts

  • I do - I was trying to bodge an incorrect adaptor to fit but failed - fitting a IS caliper to an PM adaptor.
  • p4029_250.jpg Maybe it's an IS to Post



    p4031_250.jpg
    not Post to IS adapter
    Neil
    Help I'm Being Oppressed
  • Forks are defintely post, so I need something that's flat on the bolt side and the fork side to get the mount on there right.

    The Red one above doesn't look right, but the Black one might work. Is it an AZ mount?

    I guess I assumed that IS-Post would also work Post-IS :(

    Found this which looks like it'll do the job:

    IStoPost180.jpg
  • You need Post to IS (fork to brake) ie the bottom one. They are both A2Z. The top one is an IS to Post maybe yours is the same. Think mounting a PM caliper on an IS fork and yours would work
    Neil
    Help I'm Being Oppressed
  • Brain fade on my part your adapter isn't threaded! Is it?
    Neil
    Help I'm Being Oppressed
  • Yup, fork and the mount I have are both threaded :(

    Bit gutted to be honest, but hopefully still enough time to get sorted for the weekend.

    Thanks for your help.
  • My guess is you need a PM-PM 18/60
  • Yup, fork and the mount I have are both threaded :(

    Bit gutted to be honest, but hopefully still enough time to get sorted for the weekend.

    Thanks for your help.

    Wrong mount then chap, sorry. :(
    Neil
    Help I'm Being Oppressed
  • superstar do adapters and have an image of each type
    might be worth looking on there
  • Thanks Matt, it was a Superstar adapter I got. Unfortunately they do the Post-to-IS, but not IS-to-Post :(

    Ordered a Hope adapter from CRC as they're usually uber quick on the delivery front: http://www.chainreactioncycles.com/Mode ... elID=13735

    Although it says it's not Marzocchi compatible, some of the comments below suggest that it may be alright (and on an 08 fork which is what I have). So fingers crossed I should be sorted for Sat.

    Seems a bit of an issue this though, which is weird when it's experienced by so many people. Although there is a few mounts mounts out there, there's no where near as many as for mounting Post-to-IS.
  • that hope adaptor will work as its what i have on my manitou's, But! its a PM fork to IS caliper +20mm so you'll need a 20mm larger disc!
    Timmo.
    After all, I am Cornish!
    http://cornwallmtb.kk5.org/
    Cotic Soul, The bike of Legends!:wink: Yes, I Am a bike tart!
    http://www.bikeradar.com/forums/viewtop ... 1#16297481
  • I'm fairly sure my XTR caliper is meant for a 160mm disc, and I have a 180mm disc so I should be ok. Although I'm making assumptions again so could very easily be wrong, haha.
  • nicklousenicklouse Posts: 50,675 Lives Here
    I've just got an XTR front disc brake with an IS mount that I'm wanting to fit to my Post mount Marzocchi forks. I've got an adapter which seems to be a standard shape across a few companies (bike fridge etc). One side fits fine and has a nice flat edge for the bolt to sit against. The other end is curved and the bolt won't sit against it flat. Does anyone have any experience of this problem?

    Adapter looks like this:

    Type3IStoPostF180.jpg

    The end I'm having problems with is highlighted in Red.

    limk now working. Wrong mount. that is IS fork to PS caliper.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • All sorted now. Ordered a Hope IS-PM +20 mount from CRC and it fits perfectly 8)
  • nicklousenicklouse Posts: 50,675 Lives Here
    13735.jpg

    this one?

    spot the difference.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
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