Removing Wear in Brake Lever Components

[Jamie]

I am currently cleaning and fettling the cross shaft and the associated components on my Ruby. Not surprisingly, there is wear in the moving components. 

There is slack in the hole in part BK76 where part BK57 fits. I have a new trunnion, so there is no wear in that now. To minimise the slack on the hole, I am peening all around it to try and reduce the size of the hole. This is working to a degree, but I suspect that there will still be some looseness. Does anyone have any other methods of taking up the slack, other that either welding it up and starting again, or replacing the part?

Also, the thread on part BK68 is completely shot, so that will need addressing too.


  Screenshot 2025-05-25 094420.png (Size: 191.65 KB / Downloads: 283)

[Robert Leigh]

For BK68 in particular you could drill out the existing 'stud' and replace with a setscrew and nut to hold it in place. Do not use Whitworth thread since this has lower tensile strength than BSF.

[Chris KC]

It's definitely worth chasing after all the loose and stiff joints in the system if you have aspirations to effective braking.
I'd be very surprised if you could find a better replacement part, unless yours is really shot.
About the only two possibilities you haven't mentioned are (i) boring oversize and using a larger pin - personally I'd discourage you from doing so as there's already little enough metal - or (ii) on forged parts, get a blacksmith type chappy to heat the thing red and 'shrink' it back to size with a hammer (probably more effective / durable than cold peening).

[Jamie]

Robert.
Thank you for the point about thread choice. I was mulling over whether to do your idea or make a new one. I prefer yours.

Chris.
I agree about the inadvisability of boring out the hole, but had not considered heating and shrinking it. I may have a go at that as I have a good heat source and an anvil.

Jamie

[David Cochrane]

The BK68 assembly is available new from A7 Components.

[Jamie]

The BK68 assembly is available new from A7 Components.

Thank you, David.

[Jamie]

After a combination of peening, heating and hammering, I have managed to reduce the slack in the hole. It is not perfect, but it is an improvement.

Now comes the challenge of trying to remember how it all goes back together again. I took lots of photographs, but none really helps as I missed lots of details. Hey, ho.

Jamie.