Canti brake bosses missing - what do I need?

Stressed

Muddy Fox Fan
I'm sure the diameter is slightly smaller than standard. I found some bosses in my spares, but they don't screw into the holes.

The brakes I'm trying to fit are Avid SDs. Unless I'm missing something really obvious, I cannot see how the spring can be adjusted.
Are there no little screws near the base of the arms?
 

retrobate

Overbury's Fan
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On my bonty frame the cantie studs are not like other frames.
The bolt that holds the brake on also makes up part of the stud, from memory there is the 6 mm bolt about 35 mm long that goes through the brake and screws into the frame. There should also be a stepped sleeve about 22 mm long that has the same external dimensions as a normal cantie stud 8mm OD stepping up to 10 mm OD.
 

Carge

Retrobike Rider
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Standard brake bosses don't fit - I know - I tried :(
I think KB used an M6 thread.

Good news is - I think Synlos might have the answer......
Check out his MIG Repro parts thread.

Down near the bottom of the first post is....

Canti-studs for Bontrager frames and forks. Titan 3.7165

40€/pair (8x)
 

slackboy

Bontrager Fan
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The bonty rear studs are just a loose sleeve and the bolt goes directly into the frame, as said above.

There are some detailed pictures here:


Haven't got much advice re: the spring tension, other than bending the springs in the v brake a bit to create tension there
 

Spanner

Dirt Disciple
TriAligns are direct fix to the stay stubs. The bolt provides rigidity. And the spring can be tightened or loosened just by using a spanner. When I removed those old Avids, I found myself with neither boss, nor any methos od tensioning the reaplcement brakes.
 

Spanner

Dirt Disciple
Standard brake bosses don't fit - I know - I tried :(
I think KB used an M6 thread.

Good news is - I think Synlos might have the answer......
Check out his MIG Repro parts thread.

Down near the bottom of the first post is....

Canti-studs for Bontrager frames and forks. Titan 3.7165

40€/pair (8x)

That sounds like a solution. For the stud, anyway. If I cannot find a way of increasing the tension in the Avid SDs, I'll have to look for a more adjustable brake. I've found the thread you referred to, so I'll make contact with Synlos. Thank you.
 

retrobate

Overbury's Fan
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Are you sure that you dont have 4 sleeves? The 2 that belong to the Avids (see pic (hopefully)) and the 2 that are from the frame as shown above and also see here


One may be stuck inside of the other.
 

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ishaw

Gold Trader
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That's the point I was trying to make. There must have been a boss/sleeve or something on there if the brakes came off the frame. They don't pivot on thin air.
 
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