I’ve been doing LOTS of research on my next electric bike build. During this process I came across Shimano’s affordable sealed gear hub and Rohloff’s boutique and bespoke hub drive ($$$$$). Basically a hub gearbox replaces the cassette on a mountain bike/ street bicycle and reduces the maintenance exponentially. You can also shift gears without pedaling and go from the lowest to highest gear or skip anywhere in between on a whim so long as you’re not pedaling.



The lack of a derailleur is also good for ground clearance. I believe a tensioner could be placed higher, similar to the high pivot design you see on downhill race bikes currently which would even further protect it from impact with rocks and things you might encounter on a trail.





This might be the first instance of me showing enthusiasm for a belt drive vehicle.




^^^ this is a neat design. Not having to clean a cassette and only have to bother with an oil change every 5000 kilometers/ 3106.856 miles is IMO a legit trade off.

On mid drives that cannot or should not shift under power I can see a potential issue. But that’s probably easily fixed with sensors etc.

Has the moto world ever embraced this tech? Why didn’t it succeed?

That really is a neat design.
I wonder if it could handle the full power and speed of a motorcycle ICE engine or a full-scale electric motorcycle motor and not overheat over long distances?

I would think that a real transmission transmitting “real torque” is going to need active lubrication, filtering and cooling - something that the engine can provide; a lot harder for the hub centered in the wheel.

Call the fancy-schmancy $1500 boutique hub place and ask him what their experiences with electric bike motors. I’m sure someone has tried.

A wheel on anything with suspension is exactly where you DON"T want weight.

I am convinced that there is little on the mechanical side that has not been tried on a motorcycle over the years. geared hubs for bicycles have been around for well over 150 years.
I can't see any real advantage on a motorcycle.

Interestingly enough HRC (Honda Racing Corp) went the other way and made a mid drive gearbox for a downhill racing bicycle.



Honda Racing Corporation builds a racing mountain bike

I vaguely remember a radial engine located in the wheel of a motorcycle or something like that but other than the Shimano & Rholoff designs (which seem to be robust and require MUCH less maintenance than a derailleur) I can’t think of a gearbox being located inside the rear wheel.

As electric bikes continue to grow in popularity I wonder if the trend changes? Mid drive motors that utilize derailleur and cassette power trains tend to add significant wear in high power applications.

I’m surprised it never got past putting the engine and transmission inside the wheel phase on motorcycles.

quote:

Originally posted by stickman428:


I vaguely remember a radial engine located in the wheel of a motorcycle or something like that...

You know who did that right? The Germans.

quote:

I vaguely remember a radial engine located in the wheel of a motorcycle or something like that but other than the Shimano & Rholoff designs (which seem to be robust and require MUCH less maintenance than a derailleur) I can’t think of a gearbox being located inside the rear wheel.

The first was the Megola.



It was a rotary engine, not a radial. In a rotary, the crankshaft (the bike's wheel axle) is stationary and the entire crankcase and cylinders (to which the wheel spokes are attached) rotate around it. These powered many World War I aircraft, in this case with the propeller bolted to the crankcase, but could only make so much horsepower until the torque reaction became too great to deal with. Without a clutch, starting and stopping the bike must have been … interesting. I don't know what they did to overcome the total-loss oiling system that most rotaries had. Bad enough in an airplane, this would be dangerous for a motorcycle. This bike was a curiosity and not at all practical.

As for the transmission in the rear wheel, I think the Vespa scooter has it. I'm pretty sure the engine moves up and down with the swingarm.

The Batpod in the Christopher Nolan Batman movies was a custom
Built bike with the transmission as you describe it. Go to 3:17 https://youtu.be/ckd84Ho1fKQ

quote:

Originally posted by hrcjon:
I am convinced that there is little on the mechanical side that has not been tried on a motorcycle over the years. geared hubs for bicycles have been around for well over 150 years.
I can't see any real advantage on a motorcycle.

Sturmey-Archer patented an epicyclic gear hub gear for bicycles and motorbikes in 1901. It appears the company was making motorcycle gears about 1926, by perusing the history section of the following link. The company still makes hub gears which can include braking and a dynamo for lighting.
https://www.sturmey-archer.com/en/about
My first two bicycles had a simple 3 speed SA units and they were foolproof sealed units requiring essentially no maintenance other than occasional adjustment of the chain/cable gear change mechanism.
Actually I am amazed the company still exists and has never been taken over. Thank you OP, brings back so many memories of my youth cycling around Bedfordshire.

There is another interesting player in the non-traditional bike drivetrain market. Pinion gearboxes.

I think the next generation of transmission gearboxes will be the next big leap in mountain bike design. It hasn't beaten out the derailleur yet, so I guess we are waiting on the next generation. I would really like to ride one. Pretty sure Shimano and Sram are working on something similar.

Positives:
-Weight of the gearbox is in the center of the bike
-I like the belt drive
-All the gears are internal so everything stays cleaner

Cons:
-Current model 1.5 lbs heavier than conventional gears
-I don't like the grip shift, they need to figure out how to make it work with thumb shifting
-Cannot shift while under pedal load

If they can figure these cons out, I want one.

Pinion gearboxes

Zerode mountain bikes (hard to find one to test ride, made in New Zealand)

I have an Electra Townie with the 3 speed rear hub. No cassette. I was looking to build it as an Ebike with a motor that mounts in the front crank housing. But I think the added torque would damage the 2 speed rear hub.