Rear brake not long enough

[apb]

Hi,

My latest project I thought I'd repurpose some Tektro r539 long reach brakes that have a 57mm reach. They came off a bike that sadly passed away. The front brakes fits on very nicely but the rear is millimetres short.
The frame is a thorn audax and on their website they have a similar bike with a shimano r451 brake set that also have a 57mm reach.

Am I missing something? Is there something I can do to gain 2 mm to get the Tektro to fit.

 

[Yellow Saddle]

See if there is enough meat in the slot and file it down a bit.

 

[HLaB]

Just a stab in the dark, its not fitted with 650 wheels is it?

 

[jim55]

Just a stab in the dark, its not fitted with 650 wheels is it?

^1 those. Wheels look too small

 

[Smokin Joe]

^1 those. Wheels look too small

There are rack mounts on the seat stays so the frame will not be close clearance.

 

[simon.r]

Probably a silly question, but is the wheel sitting fully in the dropouts?

 

[Yellow Saddle]

Just a stab in the dark, its not fitted with 650 wheels is it?

I must say, now that you point it out, that clearance is huge. I wish I had clearance like that.

 

[Ajax Bay]

Difference in radius between 700c and 650b (with same width/height tyre) is 19mm.

 

[apb]

Probably a silly question, but is the wheel sitting fully in the dropouts?

it wasn't. Though it could do with being 1 - 2mm longer. so I may file it a little.