What I find interesting about this setup is the way the disc is surrounded by the hub. Maybe they were concerned about getting maximum hub width for the spoke pattern?
I wondered about that, couldn't come up with an answer.
One thing, though. There wouldn't be the problem of the spokes loosening when the brake drum expanded with the heat. IIRC, that was worse with large drums (therefore short spokes).
I may have invented this fuzzy recollection with no interference from actual facts. But I think the racer/engineer Peter Williams designed the Matchless disc/wheel setup from scratch, i.e. it wasn't a retrofit. So I'd be inclined to think the world-renowned rdguy is right: that it's a rigidity and anti-distortion thing.
Williams also designed the seven(?)-spoke magnesium wheels on Tom Arter's mid-'60s G50 racer; evidently everybody had a good laugh at those and then adopted them. P.W. also kept Norton competitive in roadracing far longer than its antique engine should have allowed.
Or perhaps more simply, forks, triple clamps and wheels were rather narrow at the time, and the calipers they tried to adapt rather beefy. The calipers would not have cleared the spokes, hence the "basket" configuration. Spokes coming loose from drum heat just does not happen in my experience.
The picture is a little grainy, but could it be the disc brake assembly is retro-fitted inside an existing drum brake hub?
ReplyDeleteJoe:
ReplyDeleteI wondered about that, couldn't come up with an answer.
One thing, though. There wouldn't be the problem of the spokes loosening when the brake drum expanded with the heat. IIRC, that was worse with large drums (therefore short spokes).
rdguy
I may have invented this fuzzy recollection with no interference from actual facts. But I think the racer/engineer Peter Williams designed the Matchless disc/wheel setup from scratch, i.e. it wasn't a retrofit. So I'd be inclined to think the world-renowned rdguy is right: that it's a rigidity and anti-distortion thing.
ReplyDeleteWilliams also designed the seven(?)-spoke magnesium wheels on Tom Arter's mid-'60s G50 racer; evidently everybody had a good laugh at those and then adopted them. P.W. also kept Norton competitive in roadracing far longer than its antique engine should have allowed.
Or perhaps more simply, forks, triple clamps and wheels were rather narrow at
ReplyDeletethe time, and the calipers they tried to adapt rather beefy.
The calipers would not have cleared the spokes, hence the "basket" configuration.
Spokes coming loose from drum heat just does not happen in my experience.
It looks like only the bear side has the large diameter? I like JPs explanation.
ReplyDeleteI see no bear!
ReplyDeleteSpokes coming loose from drum heat just does not happen in my experience
ReplyDeleteI'm fortunate to have missed that era by a couple of years, so it's hearsay on my part.
Good hypothesis for the basket configuration, too.
rdguy