'27 J spokes

[Martin Pettingell]

I am working on a '27 J

The front wheel hub outer bearing race is badly pitted on one side and not usable as is.

I picked up a used replacement hub shell which is identical in every way except that the spoke apertures on the hub flange are smaller than on the one that came off the bike.

The original hub had spoke holes 0.186 +/- a thou due to wear. The hub was laced to drop centre rims which were of some age but probably not original.

The spokes had a shaft diameter of circa 0.160 (they were pretty rusty and hard to get a precise measurement) on the front and the same on the rear (the rear hub is good and can be reused)

The replacement hub I picked up is the same overall dimensions (so not I think from one of the early singles) but the spoke holes are 0.160. My original spokes will not fit the hub I acquired.

I have a parts book for '22 to '28 models. This shows part 3907 - 21 hub shell for '21 to '27 twins but also shows 3907 - 28 front hub shell for '28 twins. It is not apparent from the small images what the difference is between the two hub shells but I wondered if it was the size of spoke hole?

It shows 3943 -25 spokes for '25 to '28 twins front and sidecar & 3944-25 for '25 to 28 rear wheels.

If I understand this correctly it would seem that for '27 the spokes for front and back wheel were different.

But this may have changed in '28 and that my '27 machine may originally have a '28 front hub.

I cannot see any reference to a part number for '28 front wheel spokes other than the 3945-28 front brake shell spoke.

Does that make sense ?

I would to use the replacement hub but need to secure the right size spokes. I can have them made up here in the UK but I am not sure of the dimensions. Can anybody help me out on that please?

The alternative would be to ream out the original hub and fit sealed bearings to sit on the quill - has any body tried that ? and if so what sized sealed bearings was used?

Any help much appreciated

Martin

[1950Panhead]

Martin.
JD's came with clincher rims.
If your JD has drop center rims someone changed the rim, probably the spokes and may have drilled the hub.
Buchanan has spokes for clincher rims and spokes for drop center rims - http://www.buchananspokes.com/produc...y_davidson.asp

[Steve Swan]

'27 would be last year for front spool hub. '28 was first year for a front brake hub.

[Sargehere]

I had a friend who bought a '27JD in immaculate, weathered, original condition, about 1975. I noticed that it had lightweight spokes on the front, spool hub. This was during the drought of clincher tires, before anyone started reproducing what had been obsolete since the 1930s. My friend decided to lace drop-center rims on the bike, and ran 4.00x19 Dunlop K70s in replacement of the original 3.85x27 clincher tires that were completely unobtainable.
Suspect that something similar occurred with your bike. And you can thank your lucky star for you luck finding the right hub to make it right now, in the era of replica clincher tires.

[Steve Swan]

My best research indicates lightweight spokes were used for front and rear hubs and clincher rims on 1927 models.

Late '28 models, a heavy duty rear hub using heavy duty spokes was an option likely for sidecar use; light duty rear hub and spokes was standard equipment. '28 models, being the first year for a front brake, also described as a "fore brake;" this hub was completely different than earlier models and used spokes unique for this new hub.

[Martin Pettingell]

Thanks all.


I have an OEM front hub with 0.160 spoke holes and a an OEM rear hub with 0.185 spoke holes. I don't want to mess with an original front hub by drilling out the spoke holes

I could lace the wheels with spokes of two different gauges but that would look at bit odd I think.

A solution did occur to me.

What I plan to do is lace the front with the smaller gauge spokes (probably 9 gauge) and have the rear spokes butted at the hub end to the larger gauge (probably 7) but with the majority of the shaft the same as the front. By the time the brake and sprocket are in place it will be virtually unnoticeable.

That way I can use original hubs and the old drop centre rims. If I want to change to clinchers in the future I have that flexibility also.

My spoke maker here in the UK agrees that this should work ok.

Thanks again