Two Speed DIY Hub

George S.

Well-Known Member
https://lunacycle.com/double-gear-double-torque-motor/


Luna Cycle announced the other day that they are now selling a two speed hub motor. Back when people were saying mid-drives would be the only drives pretty soon, Prodeco announced a model with a two speed hub. The hub was branded, I think by SRAM. I thought it was a great idea, and posted about it. But then it never really showed up. When I Google all I get are old links, even to a specific model. There is a link on the Luna site to an article about these hubs.


The Chinese drive that Luna is selling says a lot about how ebike companies (really in China) can be innovative. I would say it is the Japanese approach, always making things smaller but reasonably efficient. Refine, refine, refine. This hub, front or rear, is small and only weighs 6.5 pounds. Since it is being sold as just a motor, the wheel weight is not included. You can buy it as a wheel, so one less thing to do.


I like hubs, but you can’t push the engineering of a standard hub too far. That basically means it will get hot when you climb too steep of a hill, or carry a lot of weight. Making a small motor makes it harder to shed heat. Mostly it is hills. If the motor can turn fast while climbing, it will run efficiently. That’s what the climbing gear does.


For where I ride, I can get up almost any hill. I also know that the motor bogs down on the steeper hills. Right now, if someone has steep hills, like 10% grades, it’s easier to just get a mid-drive. This could change that.


I suppose the article from 2014 about the two speed hubs shows how difficult it is to innovate in e bikes. The ebike community tends to get a marketing line out of Europe, and that means mid-drives and sophisticated pedal assists. You can’t explain this stuff to people because the US population knows nothing about e bikes. They tend to get sold on the ‘it makes you feel like Superman’ tag, if they ride a Euro bike. That’s fine, but it’s too simplistic.


So here’s a motor set up for the US limits that should accommodate a lot of bikes, not add much weight. It has the pure simplicity of a hub and gets the hill climbing of a basic mid-drive. But it will be very hard to see the public understanding it.


The ebike world would be better off if people didn’t buy marketing, if they bought ideas. A hub motor is cheap, it is simple, and it performs well until it has to climb a steep hill or otherwise be stressed. Ideally, people would know the watts they are using from the on ebike watt meter. They would know their amp hour consumption. And they would know their operating temperatures. What they are doing, now, is putting a big battery on the bikes, so capacity is much less of an issue. They put protections circuits on the bikes so they just shut down. But it doesn’t make people knowledgeable.

Which is better, a two speed hub or a mid drive? There is a lot to sort out, but there just aren’t enough avid riders and reviewers out there to get a good answer. For serious off road, a mid drive is probably going to be more efficient. For commuting, a two speed fixes the hill climbing issues.

(Edit to fix link. Thanks @Nirmala)
 
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harryS

Well-Known Member
The Luna Xiongda kit offers a good display, and the controller with Higo connectors,, which means very few connectors to hide, and the ones you see look good. Lots of things to like, assuming the two speed hub is not a problematic design. Over in Endless-sphere, most users beat the heck out of their motors and everything seems to break.

Trouble is it's almost $499 when you're done adding a rim. That's mid drive costs. The BBS02 was $449 a few months ago.

For $159, they got rear drive 1000W direct drive hubs with rims/tires included on ebay these days. They also have front drive kits for the same price, if you want to snap off your forks and land on your head. I know the controls are simple, if one is used to LCD's. You can almost get a battery off ebay, and stay under $499. Why isn't that the deal for a commuter?







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Nirmala

Active Member
This is an interesting concept. My biggest problem with my hub motor ebike is very occasional overheating on big hills. I do not really care about how fast I get up the hills around here, I just do not want my motor shutting down part way up. So if this would give me a low range for climbing, that would be a big improvement.

BTW, the link you posted is not working. Here is the correct link: https://lunacycle.com/double-gear-double-torque-motor/
 

Trail Cruiser

Well-Known Member
Xiongda 2 speed hub motor has been around for some time but has not gained traction in western market. Apparently, the low voltage (and low power) setup abroad causes the low gear to run very very slow, like being pulled by a winch. It is interesting that Luna is using high voltage for better speed and also installed a built-in protection from overheating. I wonder how many miles can those reduction gears last. This motor is very unique and very ingenious. To engage into low gear setting, the motor reverses, it uses 2 sets of one way clutches.
 
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Trail Cruiser

Well-Known Member
There is another 2 speed hub motor from SRAM but this is even a lower wattage (250 watts). Apparently. SRAM only sold the units to bike manufacturers as OEM product. It looks like it is already discontinued. The patent could be already expired (no more exclusivity) and there may be left over factories that can hot rod these motors.
(Link Removed - No Longer Exists)
 

George S.

Well-Known Member
The Luna Xiongda kit offers a good display, and the controller with Higo connectors,, which means very few connectors to hide, and the ones you see look good. Lots of things to like, assuming the two speed hub is not a problematic design. Over in Endless-sphere, most users beat the heck out of their motors and everything seems to break..

Trouble is it's almost $499 when you're done adding a rim. That's mid drive costs. The BBS02 was $449 a few months ago.

For $159, they got rear drive 1000W direct drive hubs with rims/tires included on ebay these days. They also have front drive kits for the same price, if you want to snap off your forks and land on your head. I know the controls are simple, if one is used to LCD's. You can almost get a battery off ebay, and stay under $499. Why isn't that the deal for a commuter?


I think the ardor for mid-drives has cooled. People don't need to go that route. The basic Bafang hub is cheap. In China, they sell millions, something like that, maybe a million a year. They must work reasonably well for people.

You just don't see real comparisons of a MAC motor and the Bafang, or the Golden Motors. It's like there is a $100 price tier and hubs for maybe $3-400. What do you get? What do you get when you go super-premium with the DAPU, which shows up in some nice bikes, but pretty pricey bikes?

Sondors uses Bafang, Volt bike, some Rad bikes maybe, and the very popular Cross Current. Maybe Luna should offer a Bafang pre-built for around $1000. People have to pick their price points carefully. Juiced pulls this off, but Luna aims higher.

It is transport in China, maybe a very nice toy for some in the US. We sell more upscale. The dealers sell it, find differences I don't often see, little shades of difference, in the high priced bikes.
 
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