eZee vs BMC with C-lyte controller test

[Wile E. Coyote]

I had the opportunity to do a quick & dirty test with an eZee kit motor and a rear BMC from Texas ebikes. Both running 25A, 66V via a V2 c-lyte controller (not at the same time of course).

Very similar performance:
- 28mph on level ground (no pedaling)
- 16mph up a slight hill at 50% throttle (no pedaling)
- eZee motor is slightly quieter
- rear BMC has better traction

The eZee motor has been my daily driver for the last few months. It's performed flawlessly on a 7 mile commute with a very steep hill climb, about 1000ft over 2 miles. It does, however, cause the front tire to skid on wet roads going uphill. I've switched my daily driver to the BMC. Maybe it's just the novelty/excitement, but the rear motor seems 'funner'.



*** UPDATE ***
I'm now running both motors using 2 controllers. I've found this setup surprisingly effective for my 1000ft daily hill climb.
http://endless-sphere.com/forums/viewtopic.php?f=3&t=6067

Wile E. Coyote
seattle

 

[Dr. Shock]

Can you use the two together? Are they in any way complementary?

 

[kyakdiver]

I also love my BMC rear hub motor. After going from the 408 to the EV tech I would never consider going back. I'm running 48V's and loving it. 66V's must be a kick in the butt on the hills.

Mine at 48V's eats up the hills around Whidbey Island with zero complaints. Did you shorten the wires coming out of the bmc or enlarge the wiring? I cut more than 3 feet of wire off the original down to about 6 inches coming out of the hub. Was getting way to warm before the trim down.

Kyakdiver

 

[Ypedal]

Could run both at the same time using 2 controllers from the same battery pack !!

 

[Wile E. Coyote]

One is fine for my purposes. I pedal most of the time and just need some assistance for steep hills.

 

[knoxie]

Hi

Well they are basically the same motor so I am not surprised you found them to be the same! this is the ezee from ebikes.ca? if so it is from the same factory as the ev tech motor, the BMC is a cracker, 66V is a nice safe voltage for one as well, dont go any higher unless you really have to, I run the BMX at 66V 35A, on a std old analogue none modified xlyte controller and have no problems apart from a stupid grin every time I ride it, which will be tonight as its nice and sunny and I need to get across the town quick to watch the game tonight.

Later

Knoxie

 

[TylerDurden]

Kudos. Side-by-side testing rules.

That's good news for potential ez kit buyers... seems like it has good value.

 

[Wile E. Coyote]

Thanks for the advice Knoxie. I know you and others have had some trouble with worn planetary gears. I try to keep it mellow, i.e. avoid full throttle form dead stops or up hills. Lower voltage would work for me most of the time but it's nice to be able to get near 30mph to keep up with city traffic. I also get the big stupid grin but it's followed by a look of terror when I try to use the brakes on a $220 bike form a discount store!

eZee kit is from ebikes.ca

 

[knoxie]

Hi

Nice bike too I was going to mention that, love the rear triangle reminds me of the proflex a little, its a smart looking ride as well, the BMC is cool if you keep the power down and go easy on the throttle, not all of them have the gear problem though and they are very easy to change, TH have steel ones dont know if Doug is stocking spares, be good to get some sets in, I have only ever had the problem on 1 x motor, my other motors have all been great. Just got in to my girls house after a superfast run through the park, the BMX at 66V really puts a grin on my face, my brakes are worse than yours though, they hardly work, they are cheap plastic levers and the front is a canti!! must get something sorted!! anybody know of any decent BMX brakes?

Cheers

KNoxie

 

[fechter]

Are you running the BMC with the Crystalyte v.2 controller?

 

[Wile E. Coyote]

Yes, I'm running the BMC with the C-Lyte V2. Hall sensor colors match,
Clyte - BMC
BLUE - YELLOW
YELLOW - GREEN
GREEN - BLUE

 

[catamount]

I wonder if it's possible to run two identical geared hubs using one throttle attached to two different controllers with shared batteries.

I'd like to build a 29er MTB capable of climbing 1500 ft over two and half miles on dry hard packed dirt - is that realistic goal?

Edited to correct elevation and distance after checking the precise geography at http://www.mapmyrun.com/

I calculate the grade at about 11.5%

 

[Dr. Shock]

I wonder if it's possible to run two identical geared hubs using one throttle attached to two different controllers with shared batteries.

I'd like to build a 29er MTB capable of climbing 2000 ft over about a mile and half on dry hard packed dirt - is that realistic goal?

It would be pretty easy on a 5k pot regulated controller as they have dual pots available from most scooter shops. It might be just as easy to send the signal wire from a hall sensor throttle to two controllers.

I know there's a couple of members with dual motors. How do you guys do it?

 

[lazarus2405]

I wonder if it's possible to run two identical geared hubs using one throttle attached to two different controllers with shared batteries.

I'd like to build a 29er MTB capable of climbing 2000 ft over about a mile and half on dry hard packed dirt - is that realistic goal?

It would be pretty easy on a 5k pot regulated controller as they have dual pots available from most scooter shops. It might be just as easy to send the signal wire from a hall sensor throttle to two controllers.

I know there's a couple of members with dual motors. How do you guys do it?

Exactly. It's just as simple with a Hall effect throttle; just splice a signal wire in and connect it to the second controller.

You'd want to check out RLT's offroad 2wd build: http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=3836

 

[solarbbq2003]

is that the 350watt or 500watt bmc from evtech using with a v2 controller?
is there an issue using 500watt bmc with v2 crystalyte controller?

 

[The7]

What are the gear reduction ratio for each of these two motors?

How many pole-pairs are there in each of these two motors

For initial maths:
Assumption: the V2 has a critical (or cut-off) frequency of about 400Hz.
(The V2 has low pass filtering of 2.9kHz at rising edge and 4.8 kHz faling edge of the Hall signal)

Case 1.
Assume the BMC has 8 pole-pairs and the gear ratio is 5:1
Wile E. Coyote runs his e-bike up to 28mph (=> 45 km/h).
Assume the ebike has 26" wheel.
At 45km/h, wheel rpm = (45 x 1000 /60) /( 3.1416 x 26 x 25.4/1000) rpm = 361 rpm
Rotor rpm = 361 x 5 = 1805 rpm
Then output frequecy = 1805 x 8 /60 = 241 Hz

in this case, the V2 controller should not have any problem for the output frequency is well below its critical frequency .

Case 2
If he uses Puma motor then the output frequency will be 482 Hz because Puma has 16 pole-pairs and gear ratio 5:1.
He may run into problem because 482Hz would be too close to the critical frequency.

Will redo the math if the exact data is known.

 

[fechter]

I'm pretty sure the BMC is the same as a Puma. 16 magnet pairs, 5:1 gearing.

 

[knoxie]

Hi Fechter

Yes 100% its exactly the same

Knoxie

 

[The7]

Fechter and Knoxie, thanks for the correct info on Puma and BMC

 

[solarbbq2003]

to knoxie,
is this correct: 350watt bmc/puma is ok on v2 crystalyte controller, 500watt bmc/puma is not ok on v2 over a certain rpm power is lost? as if controller cuts out?
If so that would be quite interesting as rpm might not be the real issue, might be something else?? any differences between 350 and 500watt in terms of motor structure apart from thickness of windings and number of turns, might give some clue to whats going on .

 

[knoxie]

Hello

No difference its just on the windings, same motor set-up otherwise, the V2 controllers don't work properly on any TH Puma motor as far as I know, I don't have any of the new xltye controllers, I have 6 version 1 controllers though and they all work fine now on the Pumas, I don't know what Kenny was thinking with the new controller, its a backwards step as the design has been simplified from what I can tell. Looks like the second hand value of the analogue controllers has just shot up then! ha ha, of course Kenny will make V1 controllers again I am sure, I thought ebikes ca were getting special ones made for the CA?

I dont do anything for Mark at TH anymore, Jozzer may know but I thought they were getting new Puma controllers? dont know what has happened there? there are other brushless controllers that will work ok with the Puma though, the version 2 controller has been crapping out on xlyte motors as well from what I can tell? this is bad news, it was down to us to fix the problems with the analogue controllers, If Kenny had listened all he needed to do was implement the changes that myself and others on here practised and the controller would be bullet proof, sometimes I think though that they dont want the controllers to be bullet proof if you catch my drift.

The biggest change on the V1 controllers as far as reliability goes was fitting the tab washers under the fets and ditching those green plastic silicon sleeves, I used through the hole insulating washers and fibre pads under all my controllers, pushed them all hard over 18 months and not had 1 failure of a controller.

Knoxie

 

[solarbbq2003]

I'm really wondering if the motor tested at start of this thread is 350watt or 500watt, as v2 seems to be working on that motor,
not sure if I agree that v2 is a step backwards though, it does seem to have some weak points but the guys on here are certainly gaining alot of insight into how it works and possible mods to overcome shortcomings. I think its definitely worth pursuing the v2, I think overtime it might be pretty good. I think price crystalyte are asking for the controllers is way over the top personally.

 

[Wile E. Coyote]

BMC is labeled 250W

 

[solarbbq2003]

ok thats useful, i tested some 350watt motors ( bmc calls them 350watt not sure why), the torque testing machine spat out 250watt rated, so looks like the '350watt rated' motor is really a 250watt rated motor, but is very good news you could run it on 66v without overheating oh hills.

 

[solarbbq2003]

knowing that the 250watt ( also called 350watt as far as I can tell) will run at higher rpm on v2 controller, but I think there is some issue running the 500watt ( if it turns out to be 500watt continuous rated) at higher rpm, if the only difference between the two motors is the winding thickness and number of turns that should narrow down a bit whats causing it, assuming 500watt does have same number of magnet poles as 250watt.