Problem with disc brake hub adapters

[Wildcat]

I was converting a couple bikes over to disc brakes and found a problem with the adapters that thread on to a non disc hub.
They attach clockwise and the rotor gets attached to the adapter as if the hub was made for a disc brake.

I also used a adapter to attach the caliper to the frame, but I haven't used them yet to give any info. I have a front disc brake on this bike and it works fine.
Unless you are rolling backwards then there's a problem. The hub adapter unscrews because it doesn't lock in place. The rotor will come loose from the hub. As long as I don't rely on the brake when rolling backwards it will work fine.

Normally the rotor is solidly attached to the hub.

 

[Ulu]

I would probably drill the adaptor radially and tap it for 2 dog-point set screws. Spotface the threads a bit where they hit, once things are tight.

Red Loc-tite might even be good enough.

 

[Wildcat]

What's a dog point set screw?

 

[Ulu]

It doesn’t have threads all the way to the tip. The tip is the same diameter as the root of the threads, and they extend about beyond the threads.

The length of that nose can vary with the application. This is a typical one with the standard dog point.

A dog is something that mechanically locks. Like the bolts on a bank vault door.

 

[ingola]

It doesn’t have threads all the way to the tip. The tip is the same diameter as the root of the threads, and they extend about beyond the threads.

The length of that nose can vary with the application. This is a typical one with the standard dog point.

View attachment 227717

A dog is something that mechanically locks. Like the bolts on a bank vault door.

I call them set skrews now I know the actual name.

 

[Wildcat]

I might just get a new hub and re-spoke the wheel.

 

[ingola]

I might just get a new hub and re-spoke the wheel.

That's what I would go with to sometimes buy the time you buy adapters skrews and such a new peice is easier love the new avatar!!!!

 

[Wildcat]

I was waiting on my 10,000th post to change out my avatar, and saw it was already over.

I ordered a hub, bracket and disc brake kit all for under 20 bucks.

 

[Captain Awesome]

I was waiting on my 10,000th post to change out my avatar, and saw it was already over.

I ordered a hub, bracket and disc brake kit all for under 20 bucks.

10k

 

[MattiThundrrr]

I call them set skrews now I know the actual name.

They're still set screws, that little extension beyond the thread is the dog point

 

[Starnger]

Maybe try some strong locktite?

 

[Wildcat]

I've got coaster brakes on the rear just in case. But I think it will tighten up with some heavy braking as it's the front wheel, to where it won't break free, like a cluster that needs to be hammered on to get loose after using for awhile. For my big heavy fatbike, both hubs are made for disc.

 

[Ulu]

If it is aluminum and steel threads, eventually the threads will corrode and lock the aluminum in place with a bunch of rust. That might secure it forever. It won’t happen if you put Loctite or paint or something on those threads.

Of course normally you would just use bicycle grease, but not in this condition where you don’t want it to unscrew.

Anytime you screw an aluminum part to steel you have this potential for massive gallvanic corrosion that locks the two parts together.

 

[Ulu]

I call them set skrews now I know the actual name.

There are several styles of set screws commercially available, with different styles of points and heads.

Square point, dog point, cup point, round nose, etc.

There’s one that holds the handle on my shower faucet knob, which is a long dog point, & the point is five times as long as the threaded portion. It goes clear through the shaft, valve and handle too, acting as a pin rather than a clamp.

The cup point is the most common and it’s normally found on pulleys with round shafts.

 

[Starnger]

If it is aluminum and steel threads, eventually the threads will corrode and lock the aluminum in place with a bunch of rust. That might secure it forever. It won’t happen if you put Loctite or paint or something on those threads.

Of course normally you would just use bicycle grease, but not in this condition where you don’t want it to unscrew.

Anytime you screw an aluminum part to steel you have this potential for massive gallvanic corrosion that locks the two parts together.

In my experience this only have happened with stainless steel.

 

[Wildcat]

I didn't think it was a good solid front brake after all, so I put it back to a side pull brake. I could have also done a band brake but this is the most reliable. Any time I want disc brakes, a disc hub will be the only way to go.
The 32 tooth chain wheel and 22 cog give an easy cruising gear, 53 and a low low 38, just right for an old guy.