OK, good news here (I think). After some Google-fu I tracked down this thread on the other forum.
Seems that Urban Treads and Evolve tires fit on SuperStars hubs. Since we know that Urban Treads work on the 93mm Janux hubs, it stands to reason that the 93mm hubs should fit the following tire options:
The hubs are in and I ordered a single 7" Evolve with which to test.
eLofty on Janux TB DD 4.25" Variant
The newest adapters which come with the eLofty drives have (5) pins. Out of the box these do not fit the hubs but after a very small bit of filing to clean out some of the anodized coating they slip in with a firm fit.
Snug as a bug in a rug. They squeeze onto the hub with a nice tight fit. Picture below is without an inner-tube. The “purple” tire helps show the contrast to the black hub.
By the way, what bearings are you running with these hubs? Any specific parts seem to be a better match? I’m going to assume built-in bearings will not work here?
So the way I see it, we’re left with (3) simple options, only (1) of which is probably tenable:
Get a 22mm bearing with a 10mm internal diameter to fit the step down (6900 bearings). These Sovereign Speed Bearings seem to fit the bill. That said, the small gap between the adapter and the axle would likely prevent the inner ring of the bearing from contacting the adapter, which would mean the outer race would seat against the adapter (not good).
Fully seat the adapter on the motor, crank down the hub, and just let there be a nearly 5mm gap between the adapter and the hub. This will likely put too must pressure on the pins, which will likely shorten their life.
Pull the inner bearing and spacer. The motor itself has both an internal and external bearing, if the adapter is fully seated against the hub and the outer 608 bearing is locked in place with the axle nut and speed ring(s), then the entire “assembly” should have (3) bearings distributing the force across them. The adapter pins already have a very firm seating in the hub, so the axle nut shouldn’t need to be insanely tight to make this work. Also, since the hub is Aluminum, there should be no skew in the bearing if it’s fully seated in the hub.
Here’s shot of the rear axle with the inner bearings removed and everything fully seated (without being screwed down):
As a bonus, the distance between the outer rim of the hubs on the rear axle in this configuration is ~12.3125" whereas the outer rim of the hubs on the front axle is just a fraction over 12". This means the wheel separation for the axles (in this configuration) is nearly identical.
One item to note, however, is that the threading on the axle is just barely deep enough if you use a speed ring (I may use two just in case):
Why not make a washer shaped spacer to sit between the motor and the kegel adapter. Would 3/16 aluminum plate or ABS plastic sheet not do the trick? Two holesaw cuts would give you the interior and exterior circles. Then drill the five screw holes and use longer screws.
In otherwords, I’m saying to make the kegel adapter thicker by beefing up the back side. That would push your kegel teeth deeper into the wheel core.
Does that help?
Removing one of the four bearings seems like a really bad idea. You would be asking the kegel adapter to support the inside of the rim. That would make the adapter vulnerable to impact, fatigue and cracking. Plus you would make your motor bearings load bearing like a hub wheel. The direct drive hub motors might not be designed for that type of load.
This should slot between the adapter and the motor. I’m thinking 3/16" (4.7625mm) aluminum would work quite well.
Looking at the hardware, the motor ships with Black Oxide M5 socket cap bolts @ 10mm. Since we’re looking at adding 4.7625mm, Black Oxide M5 socket cap bolts @ 15mm should be a great fit.
The only “challenge” here is the fact that the motor has a ring which acts as a fitment guide for the adapter to maintain tolerances compared the axle (as well as keeping the brunt of any force off the bolts):
Since the bolt holes in the adapter are 5.15mm, there is some slop and this may put the strain back on the bolts and not on the fitment ring.
One possible solution would be to add a fitment ring to the spacer. That said the motor fitment ring is ~3mm “high” so attempting to integrate a fitment ring onto the aluminum spacer would only allow for ~1.7625mm of material below it, which is probably not enough for it to be load bearing.
The real solution here would be to add the spacer between the motor cap and the can, which would push the entire motor cap out, although I’m reticent to start taking these motors apart (at least right now).
The alternate plan would be to add an adhesive material between the spacer and the adapter, which would likely hold everything in place just fine (the sheer holding force on this material, especially when bolted down, would be huge).
I think I have a solution for you that would require minimal effort.
Even if the adapter holes are sloppy, the torsional force will center the adapter holes on each of the bolts. The wheels will also keep the kegel pins centered on itself.
So my opinion is that that center ring is vestigial (serving no real purpose).
So doing nothing except using blue locktite on the thread holes might be the best solution.
If you are still concerned about the slop, then I woudl recommend adding a toothed lock washer between the bolt head and the adapter. I’ve done this to my Revel kit adapters with good results.
I recommend against any disassembly or tampering with the motor. It is not worth the risk and you would void your warantee for sure. Aluminum sheet is not going to be as consistent in thickness as the motor parts. Also, I suspect there would be a myriad of problems for the outer motor bearing which is likely supported by the part that you proposed moving.
I’m having the spacers laser cut this week and will drop my results here once things are set up. I will keep the toothed lock washer in my back pocket- good idea.
My adapter is slightly different to yours, it has a piece that replaces the inner bearing. They seemed to have removed it in the newest iteration of the drives. I have one of your generation but chose the ABEC adapter this time.
I believe you. I’m just surprised they would decide to make the outer bearing of the motor responsible for carrying the weight of the rider (half of it). I always felt one of the benefits of a direct drive system was that the motor bearings only carried the weight of the motors and nothing else.
Anyway, it looks like the newer ones were redesigned to keep both wheel bearings. I’m basing that on what I understood from your posts. I don’t own any elofty motors.
My early eLofty drivetrain uses a traditional two bearing setup. Maybe that’s why it’s still going strong, Shaft tolerances were always dogshit though. The inner bearing gets stuck when I swap wheels.