1924 JDCA wheel / hub offset

[slamiste]

Hello all,

I'll be lacing the wheels on this 1924 J in the near future. Sadly I didn't take any measurements when I disassembled them in the mid 1970's (yeah, that long ago). Since the front wheel uses a spool type hub (no brake) then I imagine the rim and hub are on the same vertical center line. The rear wheel uses the band brake arrangement. Can any of you confirm my front wheel theory and also let me know if there is an offset between the rim and hub on the rear wheel and if so what the offset is?

Thanks!
Steve Slaminko
OVC Chapter

[exeric]

I am sure there is no offset with the front wheel, but if you have any doubts about the rear; true it to the frame. In many cases, old bikes have slightly tweaked frames and truing to the frame is the only way to go.

[TechNoir]

When I did my 20F I offered the hub up to the front forks to check if the hub was centred in the forks (which it was) and therefore the rim had to be centred also. I trued the wheel in the front forks rather than a separate stand, that way I made sure it was right.

I did the same with the rear wheel, i trued it in the frame and that way got the rim lined up with the frame so that both wheels were correctly aligned.

John

[exeric]

Your alignment goals with any old motorcycle is to achieve orthogonality in the forks, frame, and wheels. I have had many miserable experiences in this department and if it is feasible, you should do a basic check of your frame and fork. J model forks are a bit weak and the rigid rear legs can easily be knocked out of alignment. The same is true of the rear frame tubes that go to the axel hangers. My 1916 J currently has a tweaked rigid fork, which puts the front wheel on a slightly skewed axis. In other words, the tire is off to the fender and looks like sh!t. At that point, wheel truing will not accomplish what you want, and if the problems are bad, the tire will rub the fender.

[slamiste]

Thanks Eric and John.

I'll take your advice - check out the frame and fork and if acceptable true the wheels in them.

Thanks again!

Steve Slaminko

[gsottl]

I would suggest to lace the rear wheel exactly centered in the middle of the two flat pieces in the threaded part of the axle where the rear wheel slips into the frame.

If the frame is not streight get it streightend before you assemble the bike and do not try to correct it with the rear wheel???

[silentgreyfello]

You should be able to mount the hub in the frame and eyeball it to see where the hub flanges line up compared to the center of fender. Lace up accordingly.