Thin brake discs

[Tom H]

That would be the answer as to why I can't find a P/N for the steel drum. A respected Guzzi shop felt there should be a P/N since it looked like a separate  part to them, they couldn't find it either. But....even if the hub was made as a unit and sold that way, there has to be a P/N for the aluminum hub and the steel drum. The MFG of the assy, should have that! Any part that is made up of other parts should have a parts list available, even if the parts are not available separately. Just sayin!

Tom

[Antietam Classic Cycle]

That would be the answer as to why I can't find a P/N for the steel drum. A respected Guzzi shop felt there should be a P/N since it looked like a separate  part to them, they couldn't find it either. But....even if the hub was made as a unit and sold that way, there has to be a P/N for the aluminum hub and the steel drum. The MFG of the assy, should have that! Any part that is made up of other parts should have a parts list available, even if the parts are not available separately. Just sayin!

Tom

I don't agree that there should be a part number. Why would there be when it's one piece once it's cast? The hubs were likely cast by Guzzi, since they used to do much of their foundry work in-house. Ever seen a part number for the float needle seat on the VHBs as used on our Loops? Nope, since it's cast into the carb body. Ever seen a  part number for the iron liner of Convert cylinders? Nope, just the complete cylinder.

[canuck750]

I don't know of any shop that will 'turn' a motorcycle brake disc on a lathe. I have used Truedisk in the USA several times. They use a flat plate grinding machine that grinds the disc surface on both sides at the same time. Truedisk will  inspect your rotors and let you know if they can be ground flat in spec. Their cost is very reasonable and their turn around time is excellent even shipping back and forth from Canada. The finished rotor looks like new.



https://www.truedisk.net/

[Rusnak_322]

As far as I know, the steel "brake drum" on Guzzi wheels has the alloy hub cast around it, so is not removable or replaceable.

Anything is removable if you try hard enough. 

There is nothing stopping you from turning the steel part and slipping a sleeve on that. I don't know about welding one side of the sleeve. You would think that if you were worrying about unequal expansion that a weld would soon crack.

[Antietam Classic Cycle]

Anything is removable if you try hard enough. 

There is nothing stopping you from turning the steel part and slipping a sleeve on that. I don't know about welding one side of the sleeve. You would think that if you were worrying about unequal expansion that a weld would soon crack.

The whole "point" is largely moot unless someone does something seriously stupid, the bike sets outside and the drum rusts or some other reason the drum needs to be turned in the first place. I've measured the drums of low mileage Loops (4400 miles) and high mileage (110k miles) and the drums are within a few thousandths of an inch of one another. The steel drum is very hard.

So, why hypothesize how the drum could be replaced/repaired when the likelyhood of it needing to be done is very low? Plus, Loop wheels are fairly plentiful, so a replacement could be easily sourced anyway. <shrug>