Even Smaller Direct Drive Hubs

[taiwwa]

The Grin All-axle looks interesting. For about 2kg more weight you can get regen braking, as well as a better designed torque arm.

What would happen if Grin made an even smaller and lighter motor? Make one that is 3kg, or even 2kg?

Also, what if you took geared hub motors with broken freewheel assemblies and just removed the free wheel?

 

[Chalo]

What if you took away the advantage geared hubs have over direct drive hubs, while keeping the gearbox weight, friction, points of failure, noise, heating problems, and additional maintenance of a geared hub?

 

[nicobie]

I fell for the geared hub advantage years ago with my BMC and after having to replace the gears at least 3 times in 3 or 4 months, clutch once and not too happy with the performance of it I went back to my overvolted high turn count hub (with temp sensor) motor and never looked back.

 

[E-HP]

What would happen if Grin made an even smaller and lighter motor? Make one that is 3kg, or even 2kg?

Imagine what would happen if they made them even smaller than that, like teenie tiny? Make one 200grams?

 

[glennb]

Geared hubs are the only affordable while legally compliant option for people in many parts of the world.

Please (principally Americans), try to bear this in mind when discrediting them in favour of direct drive hubs.

Our legislation is already restrictive enough. Anything that (indirectly) leads a rise in incidents involving illegal bike conversions can only make matters worse.

 

[docw009]

I prefer a bike that coasts freely, so I never cared for the way the large direct drive motors cog when rolling w/o power. The small ones don't have the same torque as a comparable geared motor, so it's always been geared motors for me.

A geared motor w/o a clutch doesn't appeal to me either, Now I have to get a controller to feed it power so I can coast? Perhaps if I were pushing an ice cream wagon, I would appreciate this kind of motor.

However, I'm all for squirrels riding ebikes.
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[E-HP]

Geared hubs are the only affordable while legally compliant option for people in many parts of the world.

Please (principally Americans), try to bear this in mind when discrediting them in favour of direct drive hubs.

Our legislation is already restrictive enough. Anything that (indirectly) leads a rise in incidents involving illegal bike conversions can only make matters worse.

A middle of the line Shimano rear hub is about a half pound, so using that as a proxy, 2kg, less 1/2 lb, leaves about 1300 grams for all the motor, gear, and clutch stuff. If this thread is about carrying your bike, then I guess that weight makes a bigger difference.

 

[Chalo]

I fell for the geared hub advantage years ago with my BMC and after having to replace the gears at least 3 times in 3 or 4 months, clutch once and not too happy with the performance of it I went back to my overvolted high turn count hub (with temp sensor) motor and never looked back.

I use a geared Jump bike hub on one of my bikes, 44V x 22A, spins about 28 mph unloaded. So far so good. It has a few thousand miles on it.

If I wanted more than 1kW into the motor, I'd use a MAC or a direct drive hub, I reckon. As it is, I'm considering adding another Bafang G020 rear hub for 2WD and twice the kick.

 

[motomech]

I use a geared Jump bike hub on one of my bikes, 44V x 22A, spins about 28 mph unloaded. So far so good. It has a few thousand miles on it.

If I wanted more than 1kW into the motor, I'd use a MAC or a direct drive hub, I reckon. As it is, I'm considering adding another Bafang G020 rear hub for 2WD and twice the kick.

Yeah, my Jump motor would do 27mph on 52V X 20A. A little too fast for me so I re-purposed the wheel/hub with a slower wind SWX02 core I dropped in. What surprized me was how much quieter the new Bafang is, and not just because it's rear mounted. At 24 to 25 mph, it's the best motor I've used, quiet and smooth like an Ezee but sized closer to a mini. I think these Bafangs can handle a true 25A controller (But they are a litle hard to find). Beyond that, I'd go bigger motor.
As you probably know, I fitzed around w/ 2WD for years and these days I'm thinking going witha bigger single motor is a better approach, until one reachs the point where that motor is too big.