Hi all,
I’m tryna find the right adapters to change my mechanical avid group to a hydraulic rival group I bought, but the brakes (I believe) are post mount rather than tab mount as shown here. I’ve attempted to buy adapters a couple of times but can’t find the right size/offset/shape. Does anyone know which adapter I should be buying for both front and rear?
Thanks!
by brooktrut
3 Comments
Your bike uses IS mounts, which use post-mount calipers. Just take the the existing calipers off (save the bolts and washers), and put your new ones right on. Unless you’re changing rotor size, then that’s it. If your new calipers are flat mount, you need IS to flat mount adapters which necessitate 180mm in the front and 160mm in the back.
There are adapters out there to attach flat mount calipers to an IS mount frame, ASSolutions is the one you’ll see most often. Read their instructions carefully though, you will be limited on the size of rotor you can use and not all frames will let you use flat mount adapters at all.
It’s much more straightforward to get some shimano post mount calipers to use with your new groupset, if you keep the same rotor size you’ll be able to just mount them on your current adapters.
I know the Straggler didn’t come with that front skewer, but it looks like it [could do what the recalled one do](https://www.cpsc.gov/Recalls/2015/trek-recalls-bicycles-equipped-with-front-disc-brakes-to-replace-quick-release-lever). This is unrelated to the brake issue you mention, but worth checking. (if the skewer is tightened and secured properly it shouldn’t be an issue, or flip the lever to the other side of the wheel where there’s no rotor to catch)