Tuesday, January 27, 2009

Fender Mounting on the Karate Monkey

I thought I'd share a solution I've come up with for mounting fenders on a bike equipped with disc brakes. If you've tried such a setup before, you likely know how much of a headache it can be. The problem lies in the fact that the disc caliper sits exactly where your mounting strut wants to be in order to connect the fender to the eyelet on the fork or rear dropout.

To make matters worse, on my Surly Karate Monkey I need to be able to access the rear caliper mounting bolts in order to swing the caliper out of the way if I have to remove the rear wheel in the event of a flat or other mechanical problem. The disc adapters supplied with my Axiom Rainrunner fenders compeltely block access to one of these bolts.

To solve this problem, I used the upper caliper bolt to secure one of the fender struts, like this:



The lower strut mounts in its stock location.

The front fender was a little more tricky. Because the Karate Monkey fork is suspension corrected, there is a large gap between the fork crown and the tire. Using the stock bracket to mount the fender to the fork crown leaves a giant gap between the fender and the tire. In addition, the upper strut on the disc side faces the same problem of interference with the disc caliper.

I shortened the struts and anchored them to the cantilever brake studs, which were not being used as it is a disc brake setup. To make sure the strut lays flat, I used some chainring bolt spacers that came with my Salsa chainring guard:


As you can see, the fender has been rotated forward a bit, leaving the stock bracket in front of the fork crown. I don't see this as a problem, since the fender still provides good coverage on the rear of the tire. It also makes a convenient mounting point for a light or reflector. You'll notice also that the bike does not have a disc front wheel on it yet. I'm still waiting for my Shimano Alfine Dynamo front hub to show up! I plan to use it in order to power a Supernova E3 headlight and possibly a taillight if I can come up with a mounting solution for it.

2 comments:

Anonymous said...

Where did you score the part to mount on the cantilever brakes. I need the same set up but the parts are hard to find.

Andrew said...
This comment has been removed by the author.