[dubthang]

I'm looking to get a new rigid fork made in the 135mm wide flavor. Since this has the possiblity to run either a front and rear hub, could somebody tell me the differences between front and rear disc tab setups? I am not sold on any one hub yet for this setup, and I am still currently farming for info.

 

[Linnaeus]

There are different options for both front and rear. Many front disc tabs are designed for a larger rotor and are not spaced for a 140mm rotor. Bikes are made with post-mount and IS mount frames, just like forks.

For the front, the IS tab is offset from the plane of the dropout by 4mm, whereas they are in the same plane (no offset) for the rear. You can, however, use spacers to push the IS caliper into the same plane (therefore mimicking the rear).

QR front and rear hubs have a different measurement for drop-out to rotor-face offset, 10mm vs 15mm respectively.

I would scroll to the bottom of this page and browse around at the different industry standards:
http://www.hayesdiscbrake.com/support_downloads.shtml

 

[Monte]

whoever made the fork should be able to tell you whether to get a "front" or "rear" hub.

 

[dubthang]

Linnaeus-
Thanks for the link. That makes everything super clear. I was curious if it was possible to run a front or rear hub by making adjustments with spacers for the brake caliper, and this clears it all up.