Brakes - Turning brake drums and shoe assemblies
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
Thanks to George Dockray who posted this information on the Yahoo! Loopframe_Guzzi news group. In George's own words:
I usually turn the drums and shoes on my drum brake bikes. Here's the set-up using an old car drum turning rig that allows the entire wheel to be mounted. Having it spoked up is best IMOH since after truing, it distorts a bit.
I turn down the shoes on a lathe with the shoes shimmed up 0.01 inch. Turn down until they will just barely fit with shims installed.
In response to a question about what to tell your machinist, George states:
If he has one of thos old-style drum turning machines, it comes with varios size cones & spacers to mount up the wheel assembly. You'll have to remove the wheel bearings BTW.
As to the mounted brake shoes, I just put a piece of 0.01 inch shim stock between the brake cam & shoeheel, mounted in the lathe with an arbor that will have to be made up. Then turn down to just barely fiting inside the drum (after it's been trued). Don't forget to grind an appropriate amount of leading edge chamfer on the pads after turning them to fit.