Sunday 2 July 2017

Clutch cable clamp

After a fatigue failure on the clutch cable pedal box end I adjusted its mounitng and replaced it. The cable pushed the end stop towards the pedal box and then continued to push the bowden cable outer through the crimped flange part.

My thought was reenforcement - rather than the bowden inner trying to push the end off the flange, instead take some of the load through the grove in the end part, ahead of the cable end, and transfer it behind the flange.

Mk1 simplest option I could come up with are plates to engage in the end groove and behind the flange connected with bolts.

U shaped plates doubled up since I cannot access the clutch end of the cable to slip a plate over - it has captive nuts. A narrower U plate on the pedal box end which matches the grove exactly.

Help from the Facebook GBS Zero page, Henry Simpkin helped convert my Sketchup mockup into DXF files using DraftSight which a friend of his then laser cut in 2mm & 3mm stainless at a very reasonable price (which I assume was at or near cost).

The parts only needed minor cleaning up to ream the holes a little, and some M4 bolts cut down to an appropriate length.

Installed with M4 bolts and nylocs.
If the bowden cable tries to push its way through the flange towards the pedal box some of that force is transferred through the bolts to behind the flange.

Thank you to both Henry & Martin who helped on the project along with David who also offered help in manufacturing.


Potential Development

  • This could also be solved with an alternate chassis mount, I wanted a remedial fix which did not require changes to the car.
  • The 2mm thick plates were fine in terms of strength.
  • I installed a mixture of 2mm and 3mm parts since for some reason I ended up with too many narrow U plates - not sure if I ordered the wrong thing.
  • May be possible to use a circlip instead if the narrow U plate that engaged with the groove.
  • I was conservative with a 35mm clearance between the bolts and chassis bracket - that could be tuned and reduced in size.


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