Stripped thread, helicoil fix?

[Salty seadog]

I've stripped the thread in a disc brake caliper post mount on the front fork .

Any advice on this?

Drilling out and fitting a bit of helicoil has been suggested . I think the material of the post mount is aluminium.

 

[Profpointy]

That should work providing there's enough meat left, and of course the challenges of (possibly?) trying to drill freehand.
Another option which might or might not be suitable for your purposes is to drill it out the next size up and tap it to that size. Again there needs to be enough meat left for this to be practical, and the larger screw will need a bigger hole in the thing being screwed on too. You don't want it falling off and jamming in the spokes of course, so need to be confident in your work !

 

[Illaveago]

Any pictures for us to have a look please ?

 

[Tangoup51]

What's your fork material? A carbon fork typically uses alloy thread inserts that are fitted into the carbon post mount, those thread inserts don't have enough material to be used by helicoil.

Which thread have you stripped, the upper or lower? If I recall correctly the upper one has less chance of being ripped out of its threads during hard braking than the lower one.

 

[Fab Foodie]

I've stripped the thread in a disc brake caliper post mount on the front fork .

Any advice on this?

Drilling out and fitting a bit of helicoil has been suggested . I think the material of the post mount is aluminium.

Bike shop.

 

[Tangoup51]

Bike shop.

Most of the LBS I know wouldn't dare touch this because of the repercussions if it went wrong, they'd more than likely sell a new fork..

 

[rrarider]

I doubt that it would prove to be successful. I had helicoils in the cast iron crankcase of a car engine and it wasn't possible to tighten the bolts in those holes to the correct torque, as the helicoils would fail.

 

[Fab Foodie]

Clear the thread then Allen bolt with locknut on the other end?

 

[Profpointy]

Clear the thread then Allen bolt with locknut on the other end?

That's probably a better idea

 

[Salty seadog]

Any pictures for us to have a look please ?

Not a lot of meat on there . I think it's aluminium.

 

[Profpointy]

Don't think there's quit enough space for helicoil, and given the arrangment, Fab's otherwise good suggestion won't work either. I'd have a go tapping the hole the next size up.

 

[Illaveago]

It looks as though there might be some thread left further in . I wonder if a longer bolt might be sufficient ?

 

[Drago]

Fill it with weld, drill and tap it out to the correct size?

 

[gbb]

If it was mine I'd do it ...or at least try it at the drop of a hat. That said, I do have helicoil kits anyway. Looking at the photo I'd say there was enough material personally. What thread is the original ?, 5 or 6mm perhaps ?
If you were local I gladly lend my kit.

Edited to say...rethought this one, see below.

 

[rrarider]

Don't think there's quit enough space for helicoil, and given the arrangment, Fab's otherwise good suggestion won't work either. I'd have a go tapping the hole the next size up.

Tap it to the next size up. You'd have to do that anyway if you wanted to use a helicoil, for the original male thread to fit. I assume that you could drill the caliper to make a clearance hole.