Star Hubs

[duffeycycles]

Chris pointed out that the wheels used on BT sidecars are the same as the bikes.I had advertised a '41 car with special wheel. Chris was right as usual --no special wheel.I believed the guy who sold it to me because he has owned over 50 knucks and flattys.Here is a '40 and later hub[IMG][/IMG]

[duffeycycles]

Here is the '36-'39 stepped hub[IMG][/IMG]

[duffeycycles]

Here is the hub that I thought was special.It does not have the smaller diameter in the center,but not stepped .Is this 3958-35 hub used on '35-'36 45"??????I can see the guys confusion.The '40 parts book calls the interchangeable wheel the spare wheel assy., sounds like a sidecar wheel not interchangeable.[IMG][/IMG]

[Jerry Wieland]

Roger Somewhat right. In 1940 HD changed the style of hub. They changed the flanges from a steel casting to a drop forging. The technique of assembly however remained the same - the hubs were still brazed until the 43/44 vintage. Starting in approximately 1944 they changed the center sleeve of the hub and eliminated the recessed grease zerk and also started spot welding the flanges to the hubs - probably because of a shorted of brass due to the war effort.

So, the hub that is powder coated in the first picture is 1943/44 to about 1957 spot welded hub. The second picture with the hub welded to the drum is a 1935 to 1939 stepped hub. The third picture is of the 1940 to 1943 vintage hub.

For those of you not familiar with steel castings/drop forgings - the difference between a steel casting and a drop forging is simple. A drop forging starts out life as a steel casting but is hammered or dropped. Old time blacksmiths realized when they took a cast steel ingot and put it in the forge and then shaped it that a couple of things happened to it, one it got smaller or compressed and two it became stronger. So it was only natural that when HD's steel cast hubs showed weakness that a forging was one of the obvious cures.

[duffeycycles]

Thanks Jerry. This info does not appear in how to restore.That means it is correct for the '41 sidecar. The '35 and '36 45" must be different than the later stepped hub ,because the part number changed.what changed in '58?

[Jerry Wieland]

Roger Yes, the black assembled wheel should be correct for your sidecar.

Here are pictures of star hubs as I know them.

The 4 variations that I am familiar with.



There are possibly more but not that I have worked with. From the left - 1935 to 1939 step hub (35/36 RL might have some differences from this because they carry a different part number).



2nd hub is 1940 to 43/44ish - still assembled with brass but utilizing drop forgings.



3rd hub is 43/44ish to 57ish - spot welded construction.



4th hub is 57ish to the end in 1966 - drive side drop forging is beefed up even more but off side remains the same as does the construction technique.



1940 and up hubs all swap parts but care must be taken with the early hub stuff. The early step hub will accept all later hardware but it is not good to mix and match. Another day I can clarify these differences if anybody so desires..

Anytime I see a HD part makes 2 changes such as was done in 1943 where they changed the center sleeve by removing the recess and also the technique of assembly by going from brazing to spot welding, it always begs me to ask the question - is it possible that these 2 changes did not occur at the exact same wheel hub. Do a few wheel hubs exist somewhere that have spot welded construction but still possess the recessed zerk or maybe some brazed hubs do not have the recessed zerk. Just something to think about....

Jerry

[Jerry Wieland]

OK I got some more pictures to show what the internal differences are in the 35 to 39 hub vs all 1940 and newer hubs. A few weaknesses showed up early in the step hub.

This first picture shows the difference in the early vs the late inner sleeve. The early one on the bottom and the later one on top.



The problem that occurred for HD was that the sleeve is stationary and the wheel hub turns. The bearing retainer spins at yet another but slower speed. On the early hub, the small shoulder that the retainer rested against would eat away at back of the retainer and eventually cause the retainer to break apart. This occurred on both the big and small retainer but seems to have been more common on the small one. Somewhere I have a retainer that was so damaged but could not locate it today. Their answer was to move the shoulder on the sleeve back and then add a hardened washer that was the same width as the retainer so that the whole back of the retainer now rested against it instead of the small shoulder on the sleeve. On the other end they added a wider thrust that pressed into the hub so that the big end retainer also had a full surface to rest against. This L profile thrust washer readily presses in to an early hub so that all early hubs can be updated to the later/better stuff.



This last picture shows some of the other changes that star hub components underwent during their 1935 to 1966 lifespan. These are all interchangeable and most seem to have occurred in the panhead era and pertain mainly to greasing of the star side tophat.



Jerry