Hub motor industry dying?

[Grantmac]

Comparing +20kw +85# motorcycles to bicycle mid-drives is a big stretch.
Likewise calling groomed trails "offroad" is stacking the deck towards a build which doesn't require any handling, just point and shoot power.

Put a pair of 500w setups through an actual offroad section and you'll see what wins. Even at 5kw the performance difference would be significant.

You can see this at the recent EMTB races that have been run on relatively smooth courses, even there in the "unlimited" class mid-drives have been the winners.

 

[Hummina Shadeeba]

dig these little 20" wheel singlespeeds for 300$ and will add a hubmotor of some sort. can fit all the electronics even between the rear wheel and cranks.

 

[wturber]

Small wheels and seat nearly directly above the rear wheel axle will probably yield a pretty harsh ride. OTOH, the apparently short wheelbase might be fun

 

[Hummina Shadeeba]

Got one! Super cheap 240$ and then shipping is 130$ Bringing to 370$
Rear wheel axle looks pretty similarly placed in relation to saddle as most bikes.

 

[wturber]

Rear wheel axle looks pretty similarly placed in relation to saddle as most bikes.

No, the chainstays are clearly shorter. But like I said, the bike will probably be nimble and fun.

I used to commute on this modded folder from time to time. I had an attachment that added two water bottle holders to the back of the seat. If you hit the right (wrong?) bump, this bike would quite literally launch the bottles out of their holders. :^)

This bike was fun as well ... in its own peculiar way. I don't find it quite as fun these days though. Though I have toyed with putting a motor on it.

 

[Hummina Shadeeba]

It is pretty tight there as u say n I’ll be getting the farthest setback seatpost possible at least to make it more comfortable. Getting closer to the axle but still I like the setback

what’s a good hub motor to fit these dropouts? Is there a 2 bolts on each side design? Seems would be nice for dropouts like these.

Will use a Vesc and want to ramp the regen as I normal do on a skateboard and use it as the main brake. just add a front v brake lever and front road caliper. I forget what’s a good throttle for using as brake too?





Then find the fastest / fattest slick that will fit.

 

[Balmorhea]

It is pretty tight there as u say n I’ll be getting the farthest setback seatpost possible at least.

If you do that, it will exaggerate the quirky weight distribution of the short wheelbase bike, making it even more of a wheelie machine.

Tall riders have the same problem on normal wheelbase bikes, where their saddles are almost directly over the rear contact patch.

 

[Hummina Shadeeba]

I think a downside with the small wheel would be increased cogging torque when unpowered and I guess when powered too, cogging with the 1/3rd unpowered teeth. in comparison to a bigger wheel diameter that would need less rotations to get the same distance.

whats a low cogging hub motor?

 

[Hummina Shadeeba]

Rear wheel axle looks pretty similarly placed in relation to saddle as most bikes.

No, the chainstays are clearly shorter. But like I said, the bike will probably be nimble and fun.

I used to commute on this modded folder from time to time. I had an attachment that added two water bottle holders to the back of the seat. If you hit the right (wrong?) bump, this bike would quite literally launch the bottles out of their holders. :^)

This bike was fun as well ... in its own peculiar way. I don't find it quite as fun these days though. Though I have toyed with putting a motor on it.

What size wheels are those? Look smaller than 20”

 

[wturber]

What size wheels are those? Look smaller than 20”

Nominally 16", but actually a little bit smaller than 16".

 

[wturber]

I think a downside with the small wheel would be increased cogging torque when unpowered and I guess when powered too, cogging with the 1/3rd unpowered teeth. in comparison to a bigger wheel diameter that would need less rotations to get the same distance.

whats a low cogging hub motor?

Based on my own experience and the watt numbers that Grin gives for their anti-cogging throttle boost feature, I think the whole cogging thing isn't as bad as people think. I think the bigger issue is that DD setups add a lot of weight to the bike and usually add larger tires that are run at lower pressure. In my case, my 40 lb electric bike grew to about 80 lbs.(lots of battery, heavy motor, onboard charger, controller, and more) So when I pedal without power, it feels pretty slow - especially uphill. It's easy to think that its the DD cogging, but I think it is mostly the weight and tires at 40 psi.

 

[sleepy_tired]

Remember that cogging is a two-way street. It's like riding up and down tiny hills. The magnets push you along they load up, like a spring. You lose some energy to heating up the motor, but it's not very much. Also reduced cogging is one of the reasons to buy higher quality DD motors.

So while you gain very little range from regen in many situations it's still more then you lose from cogging.

This is the logic behind eliminating the clutch in the Mac motor for the GMAC. You simplify the motor, improve efficiency (if anything), and reduce wear and tear on the brakes.

whats a low cogging hub motor?

The difference between a efficient DD motor and a cheap one is about 30% reduced cogging. So make sure to get a motor with the highest peak efficiency you can get.

Also keep in mind the differences in pricing.

Including shipping... A cheap 75-80% DD hub motor is something like $100 dollars. A good decent-quality 90% efficient DD hub motor is around $250-300 dollars. A low quality mid-drive setup is hard to find for less then $450.

If you are operating off of a $1000 budget to electrify a bicycle you already own... which setup is going to get the longest range? The one that is able to spend $800-900 on a battery or the one that leaves $500-600 budget for the battery?

 

[donn]

whats a low cogging hub motor?

The difference between a efficient DD motor and a cheap one is about 30% reduced cogging. So make sure to get a motor with the highest peak efficiency you can get.

I don't want to put words in anyone's mouth, but I think that's exactly why he asked. It seems like an interesting question to me, too. What motor has the most reduced cogging (a.k.a. "core loss", I think I've read here that this is a more accurate term?)

 

[Hummina Shadeeba]

Funny how cogging seems so misunderstood. Maybe I’m wrong but I don’t think it’s related to iron losses as it is strong even at the slowest speed. it is a loss mainly in that when ur coasting with a motor unpowered the cogging will reduce how far you can roll. Bike motors have a lot of magnets and teeth so it’s not that bad especially with the big circumference of the wheel to lever but it’s far from a regular wheel, at least all I’ve experienced.


And regen I think could be very productive no? All depends on what kind of riding you do but I thought some escs (vesc being one) were good with regen and a lot of energy could be caught that way, besides being a functional brake.


With a hub regen is one of the big perks I thought, and the expense of cogging. I think cogging is just like a drag but without any heat produced. Frictionless drag.

Gunna get another one of these bikes in black and be hard to even find the few wires and identify it as electric.

Still looking for a good throttle for regen


Programming to get rid of cogging, and powering through it isn’t appealing to me as it’s so complicated and ur still using power to overcome the cogging. Not much but surely there’s a hub with almost no cogging as is. ?

 

[donn]

And regen I think could be very productive no?

You could reasonably expect 10% less net battery drain, per trip.

Still looking for a good throttle for regen

That bicycle would be an odd choice for spendy, bleeding edge ebike gear. If you're using an inexpensive controller with on/off constant regen, the simplest thing is to use the "ebrake" that comes in the kit. There's a switch in it that will shut off the forward current and engage regen before the calipers contact the mechanical brake surface.

 

[Hummina Shadeeba]

I’d like a throttle that’s it’s own thing not doing regen hooked up to possible mechanical brake as well. A simple throttle/regen brake

 

[Ianhill]

I had a 20 inch wheel mxus 3k and that thing rolled nearly as well as a freehub body and the regen braking was decent simple on off not variable but as you will find regen at speed is more aggressive as the wheel/motor slows so does the regen ability at say 4mph I had very little stopping power but at 20 mph I could lock the wheel on gravel.

Be nice to see a bafang ultra frame this size with decent 20 inch fat wheels for bit of comfort and grip, grin phase runner controller at 20s field weakening enabled pulling a nice and light gear with a easy single speed setup pulling around 35mph be a nice go anywhere versatile small ride with good strong acceleration.

My next ride is a frey/ bafang ultra fat bike hardtail, mod it to 72v, swap the front fork out to an alu solid so it's simple as possible let the 26 × 4.8 tyres do the work and give it a sunrace mz90 12 speed cassette so there's nothing it can't climb that ain't vertical.

 

[donn]

I’d like a throttle that’s it’s own thing not doing regen hooked up to possible mechanical brake as well. A simple throttle/regen brake

Sure, the kit will come with a throttle, too.

• throttle that's its own thing, controls forward drive voltage, not regen.
• brake switch that overrides throttle, turns on regen.

It will work, you'll like it.

 

[Hummina Shadeeba]

What kit? I’m looking for a throttle I can twist the other way and get regen-brake

 

[Endlessphere23]

2) I've also burnt up the windings in the MXUS 45H which is the 3kw. Which was a month or two ago.

What type of continuous watts were you pumping through your 45h motor to melt it? Would 3-4kw continuous fry it?