The longer, leading shoe wraps into the drum more than a half shoe and provides more braking power.
My understanding is the leading edge 'pulls' the shoe into the drum in a self servo effect increasing the braking power. Which is why twin 'leading' shoe and double sided twin 'leading' shoe brakes were so 'performance chic' nduring the era of drum brakes.
Some of the old type cranes with mechanical clutches use similar type arrangments.
Thats interesting. Anyone know of any other applications, bikes, cars?? Was that crane clutch in the lifting gear or the driving gear Brent?
The smaller shoe would give more braking power during reverse rotation (reading flying down a hill backward) than a TLS setup. I've found the hard way yamaha TLS brakes don't do much on the wrong side of a steep hill.
Brent
I can't imagine it would be to much of a prob in MX (if you are rolling backwards you are doing something wrong
). But in enduros I can see someone been caught out on a steep hill. As a boy my first bike was a Yammy YDS5 with a twin leading f brake. In the car park and drive way, and stopping on steep hill caught me out a few times. When it rolled backwards and you had your foot off the rear brake you
really had to squeeze the f brake to have an effect
.
