xtrykr

Hiya all, I have a carbon fork with 74mm post mount, and purchased a TRP Spyre. The Mount holes lines up perfectly, but the problem I am running into is that the caliper when mounted on the fork seems to only accommodate a 140mm rotor. With the 160mm rotor that I purchased, there is about a 10mm gap between the mount points. Can someone direct me to an adapter that would allow me to bridge this gap while ensure it is secure? Or, can I just use a longer screw and use spacers/shimmy it? Thanks in advance.

Andy_K 

I think this is what you need:

TRP

bdcheung

+1

xtrykr

Thanks guys, unfortunately, it appears this adapter has been sold out for a while :S

Can I use the Shimano XTR post to post mount? Shimano XTR Mount Adaptor Front Post to Post | Chain Reaction Cycles

Andy_K 

You can use adapters from other brands. I'm reluctant to endorse the one you linked to without qualification because it says it's for mounting a 180mm caliper, but that may be assuming a 160mm post mount standard. It seems that 140mm post mounts are a relatively new thing and it may be that product labeling just hasn't caught up. It's also possible that an adapter such as you linked to would be slightly sub-optimal.

In this case I would suggest talking to a mechanic at an LBS so the person advising you can stand behind the information they provide and support you through the process of getting things up and running, even if you do the actual installation yourself. If you don't have a convenient LBS near by, consider buying from an online retailer that will provide live technical assistance, such as Universal Cycles (which I can tell you first hand is a real brick-and-mortar store with qualified mechanics). In either case, the first person you talk to is likely to be a floor salesperson who doesn't know any more than you do, but they should be happy to refer you to a mechanic once you explain the subtlety of the problem.

Alternatively, if you re-post this on the mechanics subforum here you'll probably get a good answer, although I'd bet that a few people there would tell you it's best to take it to someone who can see your fork and brake in person.

fietsbob

this is ISO to post mount, As the holes in the caliper are .. ... Post mount to Post Mount, is another game entirely ..

there maybe stacks of V brake paired washers* will do , Avid already designed their brakes that way , it offers some self alighnment
if you hold the brake on, gripping the disc, and then tighten the bolts..
then you are moving the whole caliper out on Longer bolts

* these go on the brake pad posts and usually have 1 thick & 1 thinner cupped alloy washer and 2 steel domed washers


In so far as most , same adapter , because of how the frames are designed is 1 size larger on the front than the rear .

Hence they are Marked 140r/160f, 160/180, 180/210 .. So, for 2 wheels to both be 160, for example, you need 2 different adapters .

NB as ISO (to Post Mount) is a Standard,, Any Adapter that has the numbers ^above^ will Do..

It Doesn't Have to Come from TRP wbsite.

Hit your LBS and ask. Many have a bin with extra Adapters in it it just has to be the 160f/140r type.

perhaps even other brands of Post Mount-Post Mount adapters can be sourced.