Fix stripped screw hole on fork brake mount

[Falcan]

So I crashed my bike and had to replace the front fork. I got a new fork and installed it, but wasn't able to ride due to bad weather until today. When I put the disc brakes back on I noticed the bottom of the two screws that holds the brakes in place wouldn't tighten all the way. It goes most of the way, but before getting tight it reaches a point where it just kind of turns in place. I didn't notice a problem just lifting the front wheel and spinning it, but today I tried to go for an actual ride and shortly into it the brake pads started rubbing on the disc a lot.

Since the problem doesn't happen when I just spin the wheel I don't believe my brake rotor is bent? I believe despite the brakes not feeling loose when I try and move them with my finger the screw not being tight is the source of my problem (hit a bump and brakes are knocked out alignment)?

I tried two screws which both work fine on the old fork. This means the new fork arrived with the hole stripped? I contacted the seller, but assuming they don't send me a replacement how could I go about fixing this? Thanks.

 

[harryS]

If it really is stripped, tap it for the next larger size screw. You might have to enlarge the hole in the caliper mount. Bike shop can do it too.

 

[Falcan]

Do forks use a standard screw size?

 

[harryS]

I believe they're usually metric M6 screws. You have a post mount where the screws are parallel to the rotor? Sometimes, you have screws that are too long or too short. Long ones bottom out in the fork. Short ones don't have enough thread. Both get stripped.

On further thought, a post mount doesn't have enough metal for retapping a larger screw. You may have to go to a bike shop and ask if they can install a helicoil. It's a spring like coil that replaces the stripped threads. The kit probably costs as much as having it done.