The Hodaka Club Forum

This is puzzling. Wombat 94, 1972 vintage. On the front wheel hub/wheel bearings I replaced the seals last year during the initial checkout. The outer seal, on the speedo drive side is a "correct" 32x18 size based on the sealing surface. The inside grease seal is the problem. The originally-ordered seals at 32x18 are incorrectly-sized for the sealing surface on the brake backing plate. This sealing surface is 17mm dia and the seal doesn't seal. I reordered this seal again (part 909241) and this time the replacement seal was 32x17 in size, which is correct for the inner seal surface. Puzzling-- same part #, different sized seals. The odd 17mm ID seal is a old design, rubber with no metal ring, whereas the 18mm seals have the conventional internal stiffening ring. This may mean nothing.
The only explanation I have is that my brake backing plate is an older replacement part that took a 17mm ID seal. At $35 new, the backing plate could be replaced.

Any ideas why this problem is?

If I remember correctly, the original seals on the hubs were nothing more that a thick rubber washer shaped seal sized to fit in the hub and around the mating part (brake hub, etc.) They were nothing like a regular seal, no metal ring, no lips with a spring for tension; just a thick rubber washer design.

The 32x17 seal is an old design without the internal metal ring or the garter spring in the seal lips and is less reliable than the new design. Not that important, it just distreses my Inner Wrench. If I can get a backing plate to work with the new 32x18 seal, or get/make a 17x18 sleeve to go over the smaller seal surface, I'll be able to use 32x18 seals inner and outer. Otherwise I'll plan to get a supply of the older 32x17 seals and plan to replace them more often, like at tire replacements.

Of course, one alternative is to use 6201 ball bearings with factory internal grease seals which would make the Hodaka hub seals unimportant. Most current bikes use sealed bearings, IIRC.

Silently prepping for a transcon Hodie run...