VL Hub splines

[skidshoe]

I have a acquired a number of VL hubs for my project, and have noticed that not a single hub has exactly the same spline lengths. Without using a caliper I have clearly measured spline lengths of 7/16", 1/2", 9/16", and 7/8". The 7/8" is obviously a long spline but I have seen a number of hubs with long splines much shorter than 7/8". What measurements classify a hub as short or long spline? Did the factory produce numerous sets of hubs machined slightly different throughout the VL series? And is there any difference in performance between the two?

[Steve Slocombe]

Harley made the change from short to long splines in 1932, and I've also noticed variation in spline length with some very short early ones. In those days of dirt roads the splines wore so that you could get noticeable fore and aft rotation of the wheel on the spline after a lot of miles. The driven rear wheel would be worse than the unpowered front. The long splined hubs are getting hard to find, so I've started using short splines on the front wheel. All hubs should be checked on a good rear brake drum first so you can pick the least worn ones. Don't expect any repro VL hubs, I still can't figure out how they were made.

[MMasa]

Steve
Please excuse the question as I'm not intimately familiar with the VL hub, but what makes it hard to make besides the blind spline? Are there other features inside that I've never see? Admittedly, I've only taken a few cursory looks at VL hubs.
Mark Masa

[Steve Slocombe]

Dear Mark, the hubs are swaged down in the middle, have hardened and machined splines at one end, and are then drilled with alternate countersinking for twenty spokes each side. The inside is accurately machined, and includes a step to locate the thick thrust washer on which the hub sleeve sits. The unsplined end is threaded for the outer lock nut/lock ring/lock washer. And we have a drilled and tapped Alemite grease connection, plus heat treatment. Virtually all the iinternals are hardened and machined. It was a great idea to have interchangeable wheels with many bikes also having sidecars, possibly borrowed from the BSA allegedly at the factory in the late 1920s. But way too much engineering for its own good.

[skidshoe]

Thanks for the information.

[exeric]

The whole point behind the complex, and over engineered hubs of the VL, and later star hubs was to have a steady in-house spare parts business. In the 20s and 30s; Indian, and Hen/Ex used Timken tapered roller bearing in their hubs. Indian found out the Timken bearings were not wearing out and even if they did, the user could go to Timken for new bearings. Indian shortly followed the H-D model and re-engineered their proprietary hub parts to wear out.

[Steve Slocombe]

Dear Eric, I think that's a bit cynical. William S Harley was the only graduate working for H-D in the early years, and Chief Engineer to boot. The VL hub was his well engineered solution to interchangeable wheels, at a time when maybe half of all Big Twins were pulling sidecars. I think it was just too expensive to make, like the forged VL forks, so didn't last past 1936. We see several engineering-driven projects, like the 1934-36 VL oil pump, and Harley made seven different gearboxes in 1936! Remember Harley were making all their own generators in house too, and making all nuts, bolts and washers until around 1940. I think Harley was just trying to build a well-engineered bike rather than trying to generate spares business.