'GB Coureur 66' Brakes

[HovR]

I have a pair of these GB Coureur 66 centre-pull brakes on a bike I'm working on (pics of that when it's finished).

These calipers are pretty dirty, so I was looking to do a complete dismantle and rebuild as I would my Weinmann sidepull calipers. Only thing is I've hit a few snags:


1. Removing the springs. I have the model on the left shown here.

To remove the first spring I simply pushed from the curve end inwards and up until the spring popped out. No troubles there. I tried the same thing on the second spring... SNAP! The spring snapped where it enters the circular pivot point.

I'm now thinking I should have disengaged the spring from where it meets the caliper and then slid the spring out of the circular pivot point. Is this correct? If not, does someone know the correct way?

I've had some success in making a mock-up spring out of some copper rod/wire, despite it being less than half of the correct thickness, so I don't think I should have too much trouble making another spring once I get some steel rod of the correct thickness.


2. Removing the caliper arms.

Once I've got the springs off, I can't seem to find an obvious way to remove the caliper arms. It looks like the pivot should slide out some how, but I can't seem to work out how.

On the other style of caliper in the above picture the pivot for each arm seems to have a screw head, so it can be unscrewed and removed, but there is nothing quite so obvious for the style of caliper I have.


If anyone can shed some light on either of the above points I'd be grateful!

Cheers,
HovR.

 

[stevevw]

I may be able to help you with how to take them to bits. I have been through exactly the same thing myself. When you make some springs do not forget
1. to use spring steel
2. make left and right hand versions
3. most importantly make some for me.
I will try and remember to take pictures so you can see how it all works.

 

[grumpyoldgit]

I have a pair of these GB Coureur 66 centre-pull brakes on a bike I'm working on (pics of that when it's finished).

These calipers are pretty dirty, so I was looking to do a complete dismantle and rebuild as I would my Weinmann sidepull calipers. Only thing is I've hit a few snags:


1. Removing the springs. I have the model on the left shown here.

To remove the first spring I simply pushed from the curve end inwards and up until the spring popped out. No troubles there. I tried the same thing on the second spring... SNAP! The spring snapped where it enters the circular pivot point.

I'm now thinking I should have disengaged the spring from where it meets the caliper and then slid the spring out of the circular pivot point. Is this correct? If not, does someone know the correct way?

I've had some success in making a mock-up spring out of some copper rod/wire, despite it being less than half of the correct thickness, so I don't think I should have too much trouble making another spring once I get some steel rod of the correct thickness.


2. Removing the caliper arms.

Once I've got the springs off, I can't seem to find an obvious way to remove the caliper arms. It looks like the pivot should slide out some how, but I can't seem to work out how.

On the other style of caliper in the above picture the pivot for each arm seems to have a screw head, so it can be unscrewed and removed, but there is nothing quite so obvious for the style of caliper I have.


If anyone can shed some light on either of the above points I'd be grateful!

Cheers,
HovR.

Springs will be a problem,they are heat treated after the shape is formed.

 

[HovR]

I've found a source for spring steel rod in 2mm diameter - Looking for around 2.5 preferably but it's better than nothing if I can't find the correct size. I've also got the right equipment for heating up metals to high temperatures - Whether I can get it high enough is another question, but I figure it's worth a try. It would be a shame not to use these beautiful brakes on the bike.

I played it safe and cleaned up the front brake caliper in one piece, with the springs still fitted. It's not quite as thorough of a job but I'd rather have a slightly dirty caliper than a broken one.

@stevevw - If I am successful in making some springs then I'll try and make you a set as well.

Thanks for the replies guys.