Sunday, September 21, 2014

BSA Bantam 8 Spring Clutch Conversion

The trusty Bantam, veteran of two Moto Giros and several VMCC sprints, is being prepared for a jaunt down to Spain (not under its own steam, that would be pure masochism) for the MC Piston Santander Rally

A couple of the special parts on the bike came from Peter Savage, namely the CDI ignition and the MZ conrod conversion. Both have given really excellent service. A while back the clutch started slipping so I got in touch with Peter to buy one of his eight spring clutch conversions. The delivery time was a few weeks so at the same time I bought a set of extra strong springs from Rex Caunt. Life being as it is the stronger springs were fitted, they worked and then the eight spring conversion arrived. The conversion has sat on a shelf in the workshop for a good year. I always knew that I should get around to fitting it though, the stronger springs are an effective but slightly brutal solution, a harder pull at the lever and more stress on the system. The eight spring conversion is certainly the engineer's remedy.

Taking apart a Bantam clutch is simple, putting it back together is not so easy. I had forgotten that it was designed by the Satan Engineering Design Consultancy. There is no way that one normal man can compress the eight springs enough to insert the circlip which holds the whole confounded thing together. There is a special tool but it is designed for dismantling rather than assembling. It's made even more difficult by the fact that the tool is designed to be used without the primary chain fitted but that the new primary chains are endless so you have no choice but to fit it in advance. I found in the end that the procedure could only be accomplished with extravagant swearing and several occurrences of the clutch exploding across the workshop like a grenade. The newly made tools also seem to be very flimsy in comparison with older ones, a good tip is to hold the jaws of it together with a g clamp to avoid them letting go at a vital moment...

Once fitted though the eight spring conversion is a useful piece of kit,. There's no slip and the clutch maintains a nice light action. The same conversion fits all models of Bantams. Thoroughly recommended. 

Bantam eight spring clutch conversion outer plate.
Bantam eight spring clutch conversion outer plate.

Bantam eight spring clutch conversion outer plate.
Bantam eight spring clutch conversion inner plate.

Before - six springs.

After - eight springs and a shiny machined aluminium cover.


  1. Hello, my Bsa Bantam clutch is slipping. Do you have the contact details for Mr Savage? As I'd like to purchase one of his 8 spring conversion kits, for the clutch.

    1. Hi David, the 8 spring conversion is a lovely bit of kit and very effective but unfortunately I've heard that Pete has had some health issues and is currently not making any Bantam parts. Not such an elegant solution but functional none the less would be to try Rex Caunt's stronger springs.