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A Quick Stop

TRADITIONALLY, old British bikes are not known for their ability to stop quickly. How many can remember the search for a `sympathetic' MOT tester in the 60's, or even today for that matter?

Correctly set up, the AMC half and full width hubs can produce smooth and reliable retardation, but even the FlW finned hub with it's meagre 7 inch diameter and 0.875" wide linings can struggle to perform adequately in today's traffic conditions.

The later journal bearing smooth front hubs (not to confused with the `intermediate' hub) increased the lining width to 1.125" but still failed to match the standards being set by machines like Vincent with their double sided drums.

Only in the late 60's, with the advent of the hybrids, did the 8 inch Norton hub start to slow the AJS & Matchless with anywhere near the efficiency needed to really squeal the front tyre.

Malcolm Saggers (adverts in The Jampot and previously exposed as a proponent of hydraulic clutch conversions) has taken this apparent design shortfall in hand with the production of hydraulic twin leading shoe (TLS) conversions for AMC hubs. Using wheel cylinders and shoes from some of the more popular automotive braking developments, Malcolm has updated the lowly single leading shoe (SLS) AMC front hub to perform more like it's latterday Japanese counterparts.

In this article I'll briefly explore Malcolm's conversion of a standard SLS 8" Norton hub as was fitted to my 015. His conversions for AMC finned 7" hubs is practically identical in concept save for the fact that the Norton hub requires an additional tie rod or anchor plate from the Roadholders to the brake plate, a la the one fitted as standard to Teledraulics.

Malcolm's hub conversions don't show much on the outside, but on the inside the creation of an inner base plate accommodates two new Mini wheels cylinders, shoes from a Ford and automatic adjustment rods similar to those found on Fiats.

On the outside, a standard automotive bundy pipe coupling provides connection to a master cylinder via a flexible hose (and/or bundy tube if required).

I used a Honda VF400 master cylinder of 0.5" bore from the breakers and once again called upon Alan at Mssrs Goodridge to provide the brake hose in 0.125" diameter flexible stainless. The 0.5" bore master cylinder produces a good "feel" at the lever end, but equally a 0.625" bore could be employed (e.g. VFR750 or similar) at the risk of the lever being a little `wooden' during heavy application.

On no account listen to the advice of any breaker who is relating your request to his experience with disc brakes, i.e. don't go below 0.5" diameter for the master cylinder.

Fitting and bleeding are all quite straightforward. When I couldn't get rid of the last little bit of air in the system I reverted to the practice of pumping fluid in from the wheel bleed nipple with a 20m1 hypodermic syringe, minus needle of course. This did the job.

Operation is VERY reassuring, so much so that members of my section now follow me at a more discreet distance due to the fact that, as they put it, "my rear end doesn't half come up fast at junctions".

With just two fingers on the lever you quickly forget about the rear brake pedal, other than to use the brake light to warn others that they're about to go where you've just avoided being. As most modern brake master cylinders come equipped with a brake light micro switch, it occurs to me that it would be wise to use it.

	The result may look undramatic, but the effects are worth the effort

The cost of the bare conversion is in the region of £80 but you'll have to invest additionally in the brake hose and or pipes. Malcolm will fit the unit for you (at cost) if you can take your machine to Newmarket and in any case it's always better to provide him with the complete wheel/hub to ensure that all fits perfectly.

Overall, it has to be said that whilst the conversion obviously detracts from the originality of a machine, after a few miles you wonder how you ever rode the bike

Chris Read