Mid drive

[Ajaym]

Idly scanning the Alibaba web site I noticed that some of the Chinese manufacturers are now producing bikes with a mid drive motor integrated into the frame in the manner of the high end European makers. Anyone out there have any knowledge of these bikes? Are we likely to see any of the UK suppliers bringing them in?

 

[Deleted member 4366]

UK suppliers are luddites, so it takes them ages to adopt new technology. You can't blame them, though, because they've put a ;ot of work into sorting out all the problems with their present bikes so that you can get a reliable one.

There's a few Chinese crank drives that need special frames. I guess the one you're referring to is the Bafang Max Drive, which you'll be seeing in a lot of electric bikes in the not to distant future.

https://www.flickr.com/photos/124842000@N08/sets/72157665954096671

 

[shemozzle999]

Check out this dealer, they do 2 versions Bafang Max or Shimano Steps:

http://www.tringmotion.co.uk/BE-30-E-BIKE-MTB-275-ALIVIO-9S-BAFANG-MAX-DRIVE

 

[trex]

You can get the KTM Ventura 9 for £1,600

http://www.directcarparts.co.uk/cycling-c6/electric-bikes-c16/ktm-ventura-cross-9-electric-bike-with-shimano-steps-drive-unit-system-p1532/s1549

A similar bike (with Shimano Steps) from China will cost about $1,200 FOB. Add all the usual importation cost and margin, it'll have to sell in the shop for £1999.
I honestly can't see anyone making a success importing them.
Bikes with Bafang Max Drive is much cheaper, about $900, a much better proposition.

 

[Deleted member 4366]

Check out this dealer, they do 2 versions Bafang Max or Shimano Steps:

http://www.tringmotion.co.uk/BE-30-E-BIKE-MTB-275-ALIVIO-9S-BAFANG-MAX-DRIVE

It uses the same battery as the Halfords Carrera Crossfire E, so it must be supplied by Bafang. I wonder who makes it?

 

[shemozzle999]

http://www.bottecchia.com/begreen/en/categoria/bici-elettriche-en/

 

[Ted B.]

Once the Chinese makes start selling mid motor ebikes in decent volumes, the prices will drop, which will be beneficial to all.

I don't think a decent crank-driven bike, equivalent to Bosch or Kalkhoff, will cost at least £1,600 in two years' time...

They will also come up with better aftermarket mid-motors, with embedded torque sensors, Bluetooth controls and diagnostic etc.

 

[Wisper Bikes]

We have been looking at mid motors for a couple of years when Bafang first announced thier Max.

We had a Wisper bike prototype made and even exhibited at last year's bike show but we and our customers were not impressed.

We didn't feel there was any difference in performance between the Max and a top end hub motor with a crank sensor. In fact we felt our Torque system was more responsive, quieter and of course not so ugly or obvious.

We are currently testing a very much more discrete mid motor and will be showing it at Eurobike. We have found hub motors are getting better and better, unless there is a marked difference in performance we will probably be sticking with the hub for some time.

 

[Crockers]

We have been looking at mid motors for a couple of years when Bafang first announced thier Max.

We had a Wisper bike prototype made and even exhibited at last year's bike show but we and our customers were not impressed.

We didn't feel there was any difference in performance between the Max and a top end hub motor with a crank sensor. In fact we felt our Torque system was more responsive, quieter and of course not so ugly or obvious.

We are currently testing a very much more discrete mid motor and will be showing it at Eurobike. We have found hub motors are getting better and better, unless there is a marked difference in performance we will probably be sticking with the hub for some time.

Don't the two give different riding experiences? But then I haven't tried your torque model I have a 2/3 year old SE which I believe us cadence only.
Are you working on more discreet battery placements aka Oxygen's offerings? I do like my Wisper but feel the current range look a wee bit dated.
Good luck at Eurobike

 

[Wisper Bikes]

Hi Crockers, the bike with the new centre motor is a step through with a completely hidden 400Wh battery, The Wisper 707, still not sure though whether 400Wh is enough.

The riding experience on both bikes was similar but the Wisper Torque system is very much quieter, less obtrusive, more "torquey" and more responsive than the Bafang Max, hence our decision not to run with it.

The mid motor is a plus for mountain bikes when you need to run the motor through the gear set, but for everyday riding, IMO not as good as a decent hub system with torque sensor.

We do have a new frame on the drawing board with a more discrete battery location, but that won't be around for a good few months.

Thanks for your best wishes for Eurobike.

 

[Crockers]

Hi Crockers, the bike with the new centre motor is a step through with a completely hidden 400Wh battery, The Wisper 707, still not sure though whether 400Wh is enough.

The riding experience on both bikes was similar but the Wisper Torque system is very much quieter, less obtrusive, more "torquey" and more responsive than the Bafang Max, hence our decision not to run with it.

The mid motor is a plus for mountain bikes when you need to run the motor through the gear set, but for everyday riding, IMO not as good as a decent hub system with torque sensor.

We do have a new frame on the drawing board with a more discrete battery location, but that won't be around for a good few months.

Thanks for your best wishes for Eurobike.

I suppose one advantage of a mid motor is the ability to use hub gears. Unless a front hub is used. My wife's Smart emotion is front hub and I prefer the Wisper rear hub.
Look forward to seeing your new design. In fact 2017 models are looking far more subtle in their design and I see Brose motors are having big inroads as they allow the manufacturer to design their own batteries and therefore they're becoming far more integrated. E.g. Bulls, Specialized, Scott Urban and BH Revo range.

 

[Deleted member 4366]

We didn't feel there was any difference in performance between the Max and a top end hub motor with a crank sensor. In fact we felt our Torque system was more responsive, quieter and of course not so ugly or obvious.

That's a good point. For speeds up to 15 mph, a slow-wound hub-motor at 36v and 20A will climb very well, and give a much more comfortable/convenient ride than a motor that drives through the gears.

I can't understand why manufactureres insist on 14A and 15A controllers. It doesn't make sense now that batteries can easily supply 20A. Woosh have seen the light, which is why some of their bikes climb like goats.

 

[Wisper Bikes]

I think it's all down to the nominal power of the motor Dave, the max power is not desperately important but if the nominal power of the controller is more than 7A the bike is not legal in the UK. A bike with a max of 20A is unlikely to have a nominal Amperage so small. I have found you can normally count on about double. So a 20A controller is likely to run a 350W plus motor?

 

[Wisper Bikes]

That's interesting Trex, I would love to install a 20A controller but as you know that takes the bike to 720W max. 250W nominal being the legal limit. Do you know what the nominal Amperage is of the controller? If you guys have found a way I would be delighted!

All the best, David

 

[trex]

...
A bike with a max of 20A is unlikely to have a nominal Amperage so small.
...

I wasn't going to reply because it seems nitpicking, you have obviously nothing to learn on e-bikes.
But let's see. Speed up to 15mph on flat roads is well within the ability of all bikes. If the same person rides two bikes, one with 10A controller and the other with 20A conroller but otherwise identical, on the same road at the same speed, what about the average current drain? Well, let me tell you, it's the same, there is no surprise. We do know by experience that power consumption depends essentially on speed and motor efficiency.
So why use bigger motors and stronger controllers? The simple truth is one size does not fit all.The more powerful controller helps more with acceleration and hill climbing. The maximum controller rating is not specified in EN15194. If you don't believe me, ask Bosch, Yamaha, Brose etc for their motor specifications. Woosh use 3 hub motors, the Bafang SWX for riders up to 15 stone, Bafang SWX02 for riders up to 17 stone, Bafang BPM for anyone needing more help. The SWX02 has a larger core than SWX, therefore can take more current, it's fitted with 17A controller and 13AH battery, the BPM has even larger core than the SWX02, so fitted with 20A controller and 15AH battery. Needless for me to add that the larger battery capacity is necessary to support higher controllers. If your bike has 10AH battery, then it's common sense not no exceed 15A if you don't want to shorten the life of the battery.

 

[Deleted member 4366]

There's nothing in EN 15194 that says you have to limit the current in any way. The limit on the rating is for the motor. i.e. the motor has to be marked/catalogued or otherwise specified as 250w. You can have whatever controller you want. The standard can't put any limit on the current because it's different at different rpm. You can have 20A and 36v (720w), which is the power from the battery - nothing to do with output power. When hill-climbing, you can have an efficiency as low as 30%, which would be about 200w of output power. Likewise when the motor is above say 60% of max rpm, the back emf cuts down the current, eventually to zero at max rpm, regardless of any controller setting.

FYI, I've seen some very powerful motors marked as 250w. I know of Bafang BBS01s marked 250w 36v 25A, and I've seen some big hub-motors marked 250w, that appear to be identical to others marked 500w. There's nothing illegal about that. It's not a loop-hole.

The standard (EN 15194) is the law. It's the written word that counts. Whilst those that wrote it probably didn't intend it, the way they wrote it does allow it.

Intended or not, it's virtually impossible to tie down the actual power of an electric bike to any sort of standard without either making the bike unrideable or making the standard so that it can't be defeated by the way the electrics on the bike work.

Finally, Mr Amps Bikes, in the unlikely event that you can't understand this, or to confirm that it's correct, next time you get a bike certified, put a 20A controller on it and see if it passes. I'll personally bail you out for the cost of the retest if it doesn't.

 

[anotherkiwi]

If you read the paper glued to your average Chinese controller it will say "rated current" or "maximum current" or both. Like 250 W motors the "nominative" or "rated" are there for compliance, what the actual maximum output is is left to the manufacturers discretion.

My choice is a 16 Amp controller for the GSM, because the power goes thought the gears 584 Watts peak @36.5 V is plenty enough. That is at the low end of the LiPo batteries useful power, peak hot off the charger is 664 W. And I have a 20 Amp controller which will be mated to my Mxus hub motor although current will be limited to 17 Amps. For the moment the project is a cargo trike so the couple of extra Amps will come in handy for the extra weight.

 

[Wisper Bikes]

This is all really important stuff! And yes I am learning something new, so thanks to you both for that.

Our SE and Torque 250W motors are capable of taking 20A of current, but I have always kept the input down because, (seemingly incorrectly) I thought the formula to work out the nominal power of a motor was the nominal Amperage of the controller x the nominal Voltage of the battery. So anything above 7A nominal would push the motor power over 250W.

the Torque bike is already 18A but I thought I was pushing it, and yes it did pass TUV tests.

Thanks.

All the best, David

 

[Crockers]

This is all really important stuff! And yes I am learning something new, so thanks to you both for that.

Our SE and Torque 250W motors are capable of taking 20A of current, but I have always kept the input down because, (seemingly incorrectly) I thought the formula to work out the nominal power of a motor was the nominal Amperage of the controller x the nominal Voltage of the battery. So anything above 7A nominal would push the motor power over 250W.

the Torque bike is already 18A but I thought I was pushing it, and yes it did pass TUV tests.

Thanks.

All the best, David

So 2017 Wisper models will now have 20A controllers, intergrated batteries and some colour variations?

 

[Wisper Bikes]

So 2017 Wisper models will now have 20A controllers, intergrated batteries and some colour variations?

Maybe!