AJS & Matchless Owners Club

It is clear that the expanding ends of the shoes are twisting outwards as the cam is operated. My understanding is that the fixed end of the shoes should be snug on the pivot pin, I.e. they should not be able to twist outwards to any extent. This inability to twist effectively prevents the expanding end from sliding off the cam. So I think you need to check how snug the shoes are on the pivot. Too much side play or the ability to twist significantly on the pivot may well be the problem. A bit of filing may solve the problem if the shoes do not rest smoothly and tightly on the pivot.

Its the one that came with the bike.

mrpjhancock wrote:Iv tried the spring thing with no luck . . . . I was at the AMOC parts shop today and tried exchanging my brake shoes for some new ones. Unfortunately my shoes werent good enough to exchange. Apparently they need to be in perfect condition!
So Im stuck with the ones I have
I have attached a photo of the brake drum its self. looks like its the hardened pads that are coming into contact

I'm intrigued, please expand more on the condition of the shoes and reason for refusal, also can you post some pictures of the shoes please.

It was explained to me that the reason refusing exchange is the fact that the machining for the hardened pads has broken out the casting.

Does anyone have a set of old brake shoes they want to sell . . . . . doesnt matter if they are worn out . . . . I would use them to exchange for recon ones .. .

Hi

Your shoes are machined in the same manner as mine - I believe this is as per design, I think someone at AMOC Spares has made a mistake.

Why not try putting a thin shim between the brake plate and shoes at the pivot pin? this should reduce the tendency for the shoes to migrate.

Regards Mick

mrpjhancock wrote:It was explained to me that the reason refusing exchange is the fact that the machining for the hardened pads has broken out the casting.

I'll take up the case, there appears to be no reason for the refusal other than the pin end. That in itself will have no detrimental effect on the shoe and won't be any problem re-lining them.

Did you have this problem with the previous cam and bought the replacement to try to cure the rubbing issue?
Before (and after operating the brake) your cam isn't covering (acting upon) the whole face of the hardened mushroom but only on the lower part. Could that be the reason why the cam is tending to lift/twist the shoe(s)? It seems that the cam isn't tall enough.
Here's my front brake and you can see that when at rest the cam covers all the face of the hardened mushroom. Could you try raising the cam by putting a washer under it and still have enough shaft exposed to fit the outer operating arm (perhaps needing a spacer collar on the outside to prevent it locking up)?

Yes my intention was to replace the cam, springs and shoes. I thought perhaps because there was some play in the cam shaft through the back plate it was twisting the cam movement and lifting the shoes. The cam is definitely the correct one as its identical to the old one (minus the worn shaft of course)

mrpjhancock wrote:It was explained to me that the reason refusing exchange is the fact that the machining for the hardened pads has broken out the casting.

Those shoes look identical to the ones I took to AMC Classic Spares and exchanged for a relined set with no problem at all.