Hi. Daft question: What’s the difference between the front hub and brake plate for 7 inch and 7 3/8 inch forks? If the same items are used for both, then surely the front wheel will sit out of line with the back wheel as the brake plate will have to go against the R/H fork leg and the hub will similarity move to the right? Or does the wheel get built differently by the wheelbuilder so the rim sits further over to the left with the hub positioned more to the right? I’m considering converting to 7 3/8 inch forks as I can’t find a 7 inch front mudguard.
There is no difference in the hub except the brake plate stay ( stud) may need changing . The difference is in the bottom of the fork legs which are wider on the 73/8 fork sets along with the yokes ( tripple trees!) . A longer axle that fills the nut also looks better. Beware of undersized replacement axles that can be a loose fit in the LH slider and cause it to fracture before it even begins to grip the axle.
From around 1956 onwards the Norton drum brake system used a brake plate that would fit all non-disc bikes. This included both Single and Twin leading shoe brake plates.
To accommodate the change in yoke widths, which occurred in 1964, both sliders were widened on their respective inner axle bosses by 3/16". The brake plate side slider also had the depth of its torque pin slot raised by 3/16" to allow for the change in position of the front wheel and brake plate. Diagram shows changes.
Thanks guys. It looks like it’s not as simple as just changing the yokes - that’s a pity. So my hunt for a front mudguard continues into its second year :-(
I've been looking for a lot longer than 2 years..
I am fairly certain that the actual mudguards are the same apart from the earlier ones having deeper side indentations to provide space for the narrower forks. My front guard is a conversion (confession time...). But steel is tough stuff to change.
Most slimline Dommies (including mime) now seem to have the deeper, valanced guards, but the more slender blade type is the one I want for my 1963 88SS. They seem to be impossible to find. The deeper ones appear to overlap in date with the valanced type in 1962 and 1963 according to Bacon's "Norton Twins".
The 1956-on slider lost the lug for Manx brake plates. It was machined and fitted with a reaction pin for Manxes, but for other machines it was left as cast
The tls brake plate on my 1963 would have been designed for wider (Commando) forks. The anchor pin that fits in the fork lugs is a short threaded (1/2" whit?) stud locked with a hex nut. I've no idea if it's original but probably the same change could be made if there's plenty of metal there on the plate.
Hi, I think I have mentioned that I have a spare that is not rusty but has a little buckle at the front lip , no brace or stays suitable for repair and painting
Hi Robert. Sent you a message/email. Thanks