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)
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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