I need help with my Dia Compe XCE cantilevers which are on my 1990 miyata grand touring 600. To summarize my problem, only one arm retracts after the brake is pulled. Before concluding that they are not adjusted correctly, please read on. I will try to explain it as quickly as possible.
Normally, the springs on a cantilever brake would go into the holes at the base of the boss. On these brakes, only the non-drive side is able to go into the hole. The drive side brake spring goes into a hole on a special piece of metal, which I’m holding in picture 1. This piece of metal becomes sandwiched between the brake arm and the base of the canti boss. It can then be adjusted using a 15mm cone wrench. (See picture 2)
The first problem is that no matter how much I adjust the piece of metal, the spring is still too loose to pull the arm back away from the rim after I brake. This is because the spring is not connected to the base of the boss but to that piece of metal. The non-drive side arm retracts fine, while the drive side arm with the special piece of metal stays against the rim.
The obvious solution would be to put new brakes on because these ones clearly don’t function properly. However, this is not possible because the bosses were designed to only be used with these brakes. At the base of the boss there is a piece of metal which actually makes the whole boss longer than a normal canti boss (see picture 3). So, when you put a normal cantilever brake arm on, the boss sticks out the end about 5 millimeters. The Dia Compe XCE fixed that by making the piece around the non-drive side boss longer than normal (see picture 4).
So, I have a set of brakes that don’t work at all, but they are the only ones that this bike will accept. I need help. Help me. Please!!!! Thank you!!!!