IMPORTANT ANNOUNCEMENT! NEWLY DEVELOPED BMC MOTORS!!!

[recumbent]

Great news, especially for people that live in hilly locations.

Ebikes are going to dominate urban commuting with products like this available.

[knoxie]

Hi

What have they done to address the magnet slip problem? I havent been in contact with TH for a long time but I found that on some BMC motors if used at high power levels for extended periods the rotor would get so hot that the adhesive holding the magnets would weaken and the magnets would spin under load inside the rotor, I have seen this on 1 of my motors and know of it happening on 2 others? have they addressed this problem? the motors still work but they slip and judder badly on acceleration and hill starts, I need to do a video to detail what i mean, they could stop the problem by simply keying 3 of the magnets in to the rotor body, they would have to be deeper magnets in order to match the others, this would solve the problem.

Knoxie

[dogman]

Sounds a lot like what happend with my fried BD36. The inner hub has a band wrapped around in with the magnets stuck to it. The outer band would get hot, and big, and start slipping around the inner hub. Wierd, I could hear it spinning, but no moving.

[bikeelectric]

I had recently decided to get a geared hub motor and these sound great. Any estimate on when these will be available to purchase ?

[hi-powercycles]

Right now, I am in the process of getting my shipment of demo motors. 4 weeks from today, I should have these motors in stock. I will keep you informed with updates when I get the test units in!

[Lowell]

How long to get the production units after that?

[pwbset]

Yeah, what's the latest? I'm in the market for an "upgrade" and giving serious thought to a 5305, but would entertain a Stryker purchase if the timing is right and the price is competitive with the 5 series. Thanks for any updates you can share!

[hi-powercycles]

We are looking at another 2-3 weeks to test and take videos of the demo units. We should start selling production units by the end of September!

[Julez]

Hi!

Any news so far?
The striker looks very tempting.
How is the efficiency, compared to the standard BMC, when just cruising on flat ground at around 20mph?

Cheers,

Julian

[pwbset]

+1 Another eager beaver here... ready for an update. Did you get the test motors yet?

[biohazardman]

I am waiting impatiently also. What's up with the motors I don't want to miss out as I have in the past. Please keep us posted

[pwbset]

Proof that companies should be very careful about releasing IMPORTANT ANNOUNCEMENTS before their time. Working in the internet business I get so sick of vaporware and "beta" software. Just let us know when it's ready for prime time.

[dirtdad]

I am not familiar with the marketing labels given in the opening post. Maybe dealer specific mods or bundles? All good stuff, mind you, I am not trying to get into dealer bashing here.

But as a dealer here is what I do know about product direct from BMC.

The existing BMC motor is now dubbed the "400W" model. Since it usually comes with a 36V 25A controller, don't do a whole lot of math.

New and available now is a "600W" model. Currently rear only, with 36V 25A or 35A controller, or 48V 35A controller.

The "1000W" motor is promised by mid October. No pricing on that model, but I have pricing on everything above.

None of the models come from the factory with metal gears. They use a tougher plastic (nylon? composite?) than previous models. The factory decided metal gears were way too loud and wore out much faster than harder plastics. Aftermarket bundles that include different gears, controllers, complete bikes, etc. are all possible of course, and you are free to have a different opinion than the factory on the gears, allowable voltage, etc., but this is how the motors are being sold stock from BMC, and how I will be selling them.

[hi-powercycles]

Finally!

I finally got hold of a few test units! Right now I have the Thunderbolt "600w" rated internally geared hub motor... A few surprises. The factory chose to do away with the steel gears and instead opted for a quieter and much lighter material. The new gears are made of a composite material that is supposed to be much stronger than the previous nylon gears. I weighed the motor personally on a shipment scale and guess what?? It is only 8.9 lbs! This is great news. At the moment, we have 25A 36V, and 30A 48V BMC controllers, and 35A and 40A 24-72V crystalyte controllers. For the crystalyte, we replace the 14 gauge wire with 12 gauge wire from the motor axle. I will do extensive tests and comparisons and will post videos on youtube within the next few days! I will keep you guys posted! thanks

[Mark_A_W]

Does it have a freewheel?

[dirtdad]

I am not sure which freewheel you are referring to, but the answer is yes in either case. I has a freewheel style, thread on mount for the cassette. And, being a geared motor, it freewheels much better than a direct drive motor. It is no Chris King, mind you, but then what is?

[Mark_A_W]

No, not the freewheel in the screw-on cluster.

An internal freewheel, so you don't spin the motor when you pedal. You can tell by spinning the motor one way - you will feel the gears wind up. Spin it the other way and it will rotate freely - if it has an internal freewheel.

[dirtdad]

...it freewheels much better than a direct drive motor. It is no Chris King, mind you, but then what is?

Yes, what I meant by that is that the motor itself has an internal freewheel.

[fechter]

Finally!

I finally got hold of a few test units! Right now I have the Thunderbolt "600w" rated internally geared hub motor... A few surprises. The factory chose to do away with the steel gears and instead opted for a quieter and much lighter material. The new gears are made of a composite material that is supposed to be much stronger than the previous nylon gears. ...

How about some pictures? What do the gears look like?

[GGoodrum]

Thanks for the updates. I'm looking forward to trying one of the new 1000W motors on the 20" folding bike in my avatar. Right now it has a front-mounted Crystalyte 5303, which works well, but is quite heavy. It is hard to move around/fold.

In the RC world, some of the helicopter manufacturers have used metal-impregnated composite material for the main rotor gear, and these have proved to be quite durable. The problem with metal gears is that metal-on-metal wears out fast. Nylon is too soft. I think these new composite-based gears might be just what is needed to allow lots more power to be put through these without excessive wear.

-- Gary

[hi-powercycles]

Hello Everybody. We had our first test with the Thunderbolt. It turns out it is very fast, but at the same time way more torquey than I expected. It seems to be a hybrid between the Original Thunderbolt announced and the Specs of the Striker. Running with 44.4v Top speed verified with GPS on our weakest controller (25A) was 32 MPH. Acceleration was impressive as well for a 25A system with 0-20MPH in the high 8 second range. Torque was noticeably higher than the 400W motor. On 37V and 25A, top speed was verified at 28 MPH. I am very excited for the tests I have in store for tomorrow! I expect to run with a 51.2v Lifepo4 pack, a 55.5v Lipo Pack, and last but not least a quick speed run with 67v (scary!) I will be using Crystalyte 35A and 40A controllers! I will definately be wearing a helmet and hopefully some padding tomorrow! Will post results!

[solarbbq2003]

Some info on bmc motors, some will already be aware of this info.
Brief rundown: original motor from china factory ( apparantly design development involved ezee company), ezee not so long ago starts getting the motors made from different factory in china ( not bmc but were originally getting from bmc china).
Bmc china motor being sold a few places for a while ( including superkids website........what the??), is sold as a 350watt motor but is actually a 250watt rated motor but 350watt sticks as its rated power. Ananda brand controller is supplied with motor to run on 36v, motor is wound for 36v use.
Teamhybrid call the motor "puma' motor, quite a few problems are identified ( eg keyway needed on axle to stabilise sideways movement), bmc rectifies the problems with input from TH ( and others). Bmc china makes higher power version by changing windings and propose its a 500watt continuous rated motor ( not verified if it is or not). Freewheel mechinism originally designed for 250watt continuous motor, a number of 500watt motors with freewheel mechanism are produced, later bmc china make 500watt version without freewheel mechanism for fear of freewheel failure ( power over its rated specs).
Various controllers used on 350watt ( i.e. 250watt version) at 36volts no problem, at 48v problem identified that higher switching speed controllers needed ( long process and problem identified by "fetch"), various controllers found to be modifiable to run bmc over 48v ( by changing 'crystal', some new controllers are found with higher switching speed chips (infineon, modified v2 & others not posted). Bmc china begin designing 1kw version from scratch to have components rated for higher power use ( including freewheel) release date unknown.
Bmc India plant starts producing 250watt version from some technology transfer from chinese plant. This thread appears anouncing new bmc motor ( i.e. 250watt version from Indian plant being supplied to usa ).
So my view would be there is probably going to be a very similar process happens to the indian made bmc motor that the chinese bmc motor went through ( from what I can gather there is very little communication between china/india plants),
other questions would be are the components in the indian made motors going to be as good as quality as in the chinese made ones.. eg nylon gears in chinese motor sourced in japan. Other issues such as metal used to make side plates quite important ( the threads for gears and disc are inserts), the ring gear quality etc etc. I think these are all unknowns on the indian made motor at present.

LindRch.jpg (61.06 KiB) Viewed 1464 times

[solarbbq2003]

oh forgot most important thing!
bmc solves problem of high torque and high speed in the one motor

[solarbbq2003]

i should mention new problem for 500watt bmc motor from china, under load at higher voltages back emf can exceed 100v when running on 72v sla batts ( not 100% sure on this information is a bit second hand), but could mean 150v fets will be needed for higher voltages ( or damn good caps)

[GGoodrum]

i should mention new problem for 500watt bmc motor from china, under load at higher voltages back emf can exceed 100v when running on 72v sla batts ( not 100% sure on this information is a bit second hand), but could mean 150v fets will be needed for higher voltages ( or damn good caps)

I think the most important feature of the new 1000W model is going to be the composite planetary gears. Nylon would not withstand the extra power, as many have already reported when trying to get more out of the existing BMC/Puma setups, and metal versions will just wear out quickly. Metal-on-metal is never a good idea without active lubrication.