As topic says, brake cable is fraying while being tightened. happens at front calliper specifically. Calipers are pre-2017. I tighten to approx. 5Nm, although Brompton specification states 8Nm.
What I already tried:
- Grabbing cable with nose pliers. Doesn’t help much. Might buy ones with grooves.
- Smoothing the groove which cable goes into. No impact so far.
What I discovered, that fixing bolt is rotating clockwise thus pushing cable down making it unwinding. Other callipers like Shimano use counter rotating washers with flat edge/hook, that prevents cable from being pushed down with rotation of the washer.
Brompton uses no such washer system, and I also tried a setup with a regular washer to no avail…
Brompton pros out there, may be there is dark magic trick to prevent my polymer coated expensive cables from destroying?
Interestingly, rear calliper doesn’t show same issue (second picture), tightening with same bolt to the same torque.
What I am thinking about is, cable might be interfering with bolt threads/groove is too wide, so might try to move correct cable groove away a little/correct shape by using fine round file…
by pipineko
2 Comments
I’ve never seen this issue before. Has it done this to multiple cables?
1. It’ll be fine, just go ride your bike.
2. Try a new cable