37 replies to this topic

[R32Egor]

Hi again

My bolt thread is definitely not 5/16 unf or M8×1 as i have also seen suggested.
The bolt thread is nearly 5/16 unf but gets stuck after about 3 to 4 threads.
Could they be 5/16 bsf?

[Spider]

If this is the bolts to mount the Caliper to the Hub, they are definitely all 5/16" 3/8" UNF.

 

The threads might need a clean up.

Edited by Spider, 01 January 2024 - 09:04 PM.
Correction to thread size !

[Ethel]

I think he means the bolts to join the caliper halves. The caliper to hub bolts are M10 for the Metro, but 3/8unf for the Mini - Minispares hybrid listed above.

[Spider]

I think he means the bolts to join the caliper halves. The caliper to hub bolts are M10 for the Metro, but 3/8unf for the Mini - Minispares hybrid listed above.

 

Thanks Ethel, yes, the Mini Hubs are 3/8" UNF. I've corrected my post above.

The few Calipers I've refurbished were 5/16" UNF for the halves.

[R32Egor]

I think he means the bolts to join the caliper halves. The caliper to hub bolts are M10 for the Metro, but 3/8unf for the Mini - Minispares hybrid listed above.

Yes thats the bolts I mean.

[R32Egor]

The bolts I have for the halves do screw in and are ok (apart from too long obviously) and 5/16 UNF threaded bolts will not screw in.

I am a bit worried about taping the screw threads with a 5/16 unf tap in case I damage and ruin the calipers.

[Ethel]

If you have the old bolts they are your best indication. In a sense it doesn't matter what they are, you'll just be looking for the closest match.

 

Measure the major & root diameters, work out the the pitch and google up some thread spec tables.

 

They could be anything, as far as I'm aware they were never offered as serviceable beyond replacement seals. Everything else on them is metric though, so some flavour of M8 would be my guess.

[R32Egor]

So i have since found out they are M8x1.0 fine thread. Thanks for the help