Hub mid-drive dual motor combos

[Chalo]

I suggest that a geared front hub could take the place of the mid drive in that analysis. And a more powerful rear hub could substitute for a second motor of whatever kind.

 

[hillslayer@]

Geared hub wouldn't always be able to dial in the perfect gearing a mid-drive is the best tool for the job.

 

[yantra yatra]

I’m tempted to give it a try. There are clearly some design issues for higher powered Ebikes.

Drive trains don’t handle high powered mid drives above 2kw well. And the top speed at 48v or 52v is not quite enough at stock (~60km/h or less).

Higher powered DD hub drives are not efficient for climbing hills, particularly at lower speeds.

Having both motors seems like overkill. When the problem should be solvable at other levels.

Having the ability to use something like this with a mid drive would be a good solution for the drive train issues. Efneo 3 Speed Chainring

This is where I feel that more R&D, from some bigger car companies for example, could help. ZF just brought out an innovative middrive motor.

With motors like the 250nm Bafang m630 now available, and CYC X1 Pro, it seems like the drivetrain solutions are the way to go, but the high torque rated IGH’s are too expensive. No clear best choice for me

 

[hillslayer@]

I’m tempted to give it a try. There are clearly some design issues for higher powered Ebikes.

Drive trains don’t handle high powered mid drives above 2kw well. And the top speed at 48v or 52v is not quite enough at stock (~60km/h or less).

Higher powered DD hub drives are not efficient for climbing hills, particularly at lower speeds.

Having both motors seems like overkill. When the problem should be solvable at other levels.

Having the ability to use something like this with a mid drive would be a good solution for the drive train issues. Efneo 3 Speed Chainring

This is where I feel that more R&D, from some bigger car companies for example, could help. ZF just brought out an innovative middrive motor.

With motors like the 250nm Bafang m630 now available, and CYC X1 Pro, it seems like the drivetrain solutions are the way to go, but the high torque rated IGH’s are too expensive. No clear best choice for me

My first one I built with the BBSHD and a hopped up 500 watt geared hub was impressive but the 1500 watt DD hub BBSO2 combo is another level still getting it tuned so they use their batteries equally as on level ground seems like using the hub alone is the way to go and turning down the hub on hills to let the mid drive pull it's fair share is not always easy.

 

[yantra yatra]

Cool that sounds like a good idea. Turn off the BBS02 on the flats and only turn it on for the hills. The lack of torque sensing in that setup is not ideal for me though.

 

[yantra yatra]

I still don’t quite understand how big a deal the efficiency issue is between the DD Leaf and BBSHD for hill climbing at moderate speed 25km/h plus. I don’t understand these things well but looking at the simulator it seems the Leaf would be ok by itself. Difficult choice

 

[ebike4healthandfitness]

I still don’t quite understand how big a deal the efficiency issue is between the DD Leaf and BBSHD for hill climbing at moderate speed 25km/h plus. I don’t understand these things well but looking at the simulator it seems the Leaf would be ok by itself. Difficult choice

If I were to use an ebike for serious transportation I would never want to climb at hill at only 25 km/h. This because climbing hills is always going to be the absolutely safest way to go fast. Same thing with headwinds. No worries about endos no matter how hard I need to brake. Stopping distances will always be the shortest for any given speed when climbing hills and even more so when a headwind is present. Therefore I would always want the most power possible so I can climb any hill in any kind of headwind.

P.S. In the EU they have a speed limit of 45 km/h for mopeds but the power limit is set a 4000 watts continuous. This high amount of power is so you can ride that moped up pretty much on any hill at 45 km/h.

 

[yantra yatra]

Yea the plus was the main part of that ‘25km/h plus’, with a mid drive on steeper hills you have to slow down with the gearing.
But it takes a lot of energy to go fast up hills, so that is the other issue, balancing speed and efficiency. There’s probably not a massive difference between the mid drive and DD, so it probably doesn’t really matter

 

[hillslayer@]

I still don’t quite understand how big a deal the efficiency issue is between the DD Leaf and BBSHD for hill climbing at moderate speed 25km/h plus. I don’t understand these things well but looking at the simulator it seems the Leaf would be ok by itself. Difficult choice

Let's do 25 MPH up a 10 % hill for 3 miles that leaf motor is going to be pretty hot.

 

[Lectriceye]

Wow, pretty interesting discussion with a lot of different thoughts and ideas. My experience in taking my factory 1000w geared hub bike into the mountains was proof enough for me that geared hubs weren't made for long steep hills. I burned out 2 30a controllers after 2 miles on 6%+ grades. I made an elaborate heatsink and put a continuous readout temp gauge on it and saw the case temperature climb to 45C in just 1/2 mile on a 7% incline. I am sure I would have reached over 100c if I had kept going, but I didn't. I am installing my BBSHD 1000w this weekend and I plan to use the hub mostly on flat terrain and the mid drive in the mountains, which is where I mostly ride. If I were doing it over again, I would have bought a mid drive, but that is water under the bridge. Now that I have learned enough about ebikes to be dangerous, I plan to build an eMTB in a few months, and it will be a mid only.

 

[hillslayer@]

Wow, pretty interesting discussion with a lot of different thoughts and ideas. My experience in taking my factory 1000w geared hub bike into the mountains was proof enough for me that geared hubs weren't made for long steep hills. I burned out 2 30a controllers after 2 miles on 6%+ grades. I made an elaborate heatsink and put a continuous readout temp gauge on it and saw the case temperature climb to 45C in just 1/2 mile on a 7% incline. I am sure I would have reached over 100c if I had kept going, but I didn't. I am installing my BBSHD 1000w this weekend and I plan to use the hub mostly on flat terrain and the mid drive in the mountains, which is where I mostly ride. If I were doing it over again, I would have bought a mid drive, but that is water under the bridge. Now that I have learned enough about ebikes to be dangerous, I plan to build an eMTB in a few months, and it will be a mid only.

My first build was a hardtail MTB rode it for 2 years with the BBSO2 lots of fun doing forest service trails bike handling was great without much added weight. Then bought an under powered fat bike and added a BBSHD and discovered how safe it feels being able to carry speed up steep mountain roads and not having to worry about being overtaken in a bad spot.

 

[neptronix]

Let's do 25 MPH up a 10 % hill for 3 miles that leaf motor is going to be pretty hot.

I did 50mph up a 5-7% hill for 3 miles with a vented leaf long ago.. i could have gone triple the distance before it overheated.
Nowadays you can run ferrofluid and experience that benefit w/o drilling holes into your motor.

I was also running 26" wheels, which i wouldn't do today with a hub. There's some additional continuous wattage to gain by using a smaller wheel.

 

[hillslayer@]

A

I did 50mph up a 5-7% hill for 3 miles with a vented leaf long ago.. i could have gone triple the distance before it overheated.
Nowadays you can run ferrofluid and experience that benefit w/o drilling holes into your motor.

I was also running 26" wheels, which i wouldn't do today with a hub. There's some additional continuous wattage to gain by using a smaller wheel.

 

[hillslayer@]

If you like small wheels just use a scooter.

 

[Chalo]

If you like small wheels just use a scooter.

Scooters suck. Real bikes can use a small motor wheel to achieve the same benefits, without all the drawbacks and facial injuries.

 

[ebike4healthandfitness]

Let's do 25 MPH up a 10 % hill for 3 miles that leaf motor is going to be pretty hot.

Indeed, if Nine Continent RH212 is any indication:

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

ebikes.ca

 

[ebike4healthandfitness]

But it takes a lot of energy to go fast up hills, so that is the other issue, balancing speed and efficiency.

It does take a lot of power to go up hills.

And any time you exceed the motor's continuous power rating it becomes less efficient and afterward must be run below continuous power rating for some time in order for it too cool down.

 

[ebike4healthandfitness]

Having the ability to use something like this with a mid drive would be a good solution for the drive train issues. Efneo 3 Speed Chainring

This is where I feel that more R&D, from some bigger car companies for example, could help. ZF just brought out an innovative middrive motor.

I'm surprised the ZF mid drive doesn't have an integrated gearbox like a lot of companies now have.

Last time I checked I counted 5 companies that had integrated mid drive with gearbox. The two that come to mind the most are Pinion and Intradrive.

First Ride: Pinion's E-Drive System - A New Motor With an Integrated Gearbox - Pinkbike

Pinion is taking things to another level with an e-bike motor with integrated gearbox.

www.pinkbike.com

Intra Drive's Combined Motor & Gearbox Fits Bikes Designed For Shimano EP8 [Updated on expanding into the aftermarket] - Pinkbike

The Scottish startup is aiming to disrupt the e-bike drive unit market. [Updated with more on expanding into the aftermarket]

www.pinkbike.com

 

[hillslayer@]

Scooters suck. Real bikes can use a small motor wheel to achieve the same benefits, without all the drawbacks and facial injuries.

Or you can add a mid-drive and keep your 29" tires.

 

[yantra yatra]

I'm surprised the ZF mid drive doesn't have an integrated gearbox like a lot of companies now have.

Last time I checked I counted 5 companies that had integrated mid drive with gearbox. The two that come to mind the most are Pinion and Intradrive.

First Ride: Pinion's E-Drive System - A New Motor With an Integrated Gearbox - Pinkbike

Pinion is taking things to another level with an e-bike motor with integrated gearbox.

www.pinkbike.com

Intra Drive's Combined Motor & Gearbox Fits Bikes Designed For Shimano EP8 [Updated on expanding into the aftermarket] - Pinkbike

The Scottish startup is aiming to disrupt the e-bike drive unit market. [Updated with more on expanding into the aftermarket]

www.pinkbike.com

Maybe that’s next. If a company like ZF made a powerful middrive, capable of peaking at 6kw instead of 600w, with an integrated gearbox, that would be a game changer

Edit: I just reckon Tesla should throw like 1% of their engineering capacity, or even a fraction of 1% at it, and there would be big innovations and improvements. If they were really interested in driving down emissions and displacing fossil fuel consumption (and thought about it well enough!) they would!

 

[Lectriceye]

Wow, pretty interesting discussion with a lot of different thoughts and ideas. My experience in taking my factory 1000w geared hub bike into the mountains was proof enough for me that geared hubs weren't made for long steep hills. I burned out 2 30a controllers after 2 miles on 6%+ grades. I made an elaborate heatsink and put a continuous readout temp gauge on it and saw the case temperature climb to 45C in just 1/2 mile on a 7% incline. I am sure I would have reached over 100c if I had kept going, but I didn't. I am installing my BBSHD 1000w this weekend and I plan to use the hub mostly on flat terrain and the mid drive in the mountains, which is where I mostly ride. If I were doing it over again, I would have bought a mid drive, but that is water under the bridge. Now that I have learned enough about ebikes to be dangerous, I plan to build an eMTB in a few months, and it will be a mid only.

 

[ebike4healthandfitness]

My experience in taking my factory 1000w geared hub bike into the mountains was proof enough for me that geared hubs weren't made for long steep hills. I burned out 2 30a controllers after 2 miles on 6%+ grades. I made an elaborate heatsink and put a continuous readout temp gauge on it and saw the case temperature climb to 45C in just 1/2 mile on a 7% incline. I am sure I would have reached over 100c if I had kept going, but I didn't.

How much do you weigh?

 

[ebike4healthandfitness]

With motors like the 250nm Bafang m630 now available, and CYC X1 Pro, it seems like the drivetrain solutions are the way to go, but the high torque rated IGH’s are too expensive. No clear best choice for me

This high torque IGH isn't very expensive:

Bafang's new automatic 5 speed IGH for fat bikes rated at 200 Nm torque

Does anyone know more about this one? https://www.bafang-e.com/uploaded/news/202405130108276816.pdf Apparently this is already on the market: https://www.alibaba.com/product-detail/Bafang-Automatic-Gears-Hub-5-speeds_1601032474027.html...

endless-sphere.com

And Bafang is actually recommending its use with the M630:

 

[yantra yatra]

How much does it cost?

 

[hillslayer@]

How much do you weigh?

Something over 225 been a few years since I have been on a scale.