BMC 600W vs Crystalyte 5304 @72V

[dirtdad]

I had the chance to run the new BMC 600W hub motor back to back with my 5304 Crystalyte at 72V. Here are the particulars of the setup: 72V 20AH of Yesa Lifepo4 batteries and an Infineon 72V 45A controller that will work with either motor. My bike is a no pedal vehicle. The only thing that keeps the comparison from being 100% apples to apples is the wheel build. The 5304 is laced to a 24" rim that is 80mm wide and a 4.25" tire (motorcycle looking stuff). The BMC is laced to a 26" rim with a slick mtb tire. The overall tire radius is the same. The only difference is the 5304 is carrying around a little more rotating weight. But not that much more surprisingly, and I have had the 5304 built on a few different tire/rim combos, I have never been able to measure a difference in performance as I have changed wheel builds. Here are some numbers.

Top speed level ground BMC 40.5 mph, 5304 42 mph. The 5304 reaches its top speed faster.

Climbing The hill I use for testing is about 1/2 mile of increasing grade, peaking at about 14% near the top then quickly leveling off. The 5304 can maintain 13 mph up that grade, the BMC 11 mph. See notes section.

Descending The BMC has the slight edge as it is freewheeling. When I turn around and descent the hill above the 5304 does 40 mph. The BMC freewheels up to 45mph.

Subjective The BMC has stronger pull in the range of say 20-30mph. They 5304 has more acceleration power at 30+. Most of the time in regular riding I do not feel a big difference. Every once in a while the BMC surprises me with its pull, other times it comes up a little short. The BMC is no noisier than the 5304. Both make a little noise below about 10mph and smooth out and get very quiet above that. The sounds are very different.

Efficiency I have not completed this comparison. I have not measured this rigorously on the 5304, but it has excellent efficiency, I have gotten 60-80 mile range, and 3-4 miles per amp hour is common. I have not measured watt hours, which would be more accurate. The BMC has just been around the neighborhood at this point.

Notes The BMC phase wires are just too small to handle this kind of power for any significant amount of time and put it at a disadvantage. I am guessing they are 16 gauge? They ARE silver/teflon, and the harness coming off the motor is about 2 feet long and I have not shortened it. At the bottom of the big hill climb they were warm to the touch. By the top of the same climb, 1/2 mile later, the were too hot to hold on to. I think heat and resistance were a big factor on the hill climb. The BMC got off to a faster start than the 5304 but faded during the climb, never drawing as many amps as the controller could deliver. Using thicker gauge phase wires could even make the BMC faster than the 5304 on the hill, but that is a project that I will take on any time soon.

Pictures and extended testing to follow.

[Jerome Daoust]

Interesting, thank you.

You are referring to the new BMC 600 W Thunderbolt, correct?

[dirtdad]

"Thunderbolt" is a marketing name given to it by another retailer. There is only one BMC 600W geared hub motor currently. I prefer to stick with factory names like the way ebikes.ca does with Crystalyte motors. Other retailers call Crystalytes Phoenix Brute, Sparrow, etc. for example

[hi-powercycles]

Wow! Nice test dirtdad! You beat me to the punch! I will be doing some testing of my own this week and it will be fun to compare notes! How do you like the Infineon controller?

[dirtdad]

Wow! Nice test dirtdad! You beat me to the punch! I will be doing some testing of my own this week and it will be fun to compare notes! How do you like the Infineon controller?

Hey, I had some catching up to do, I see you have been working hard with this new motor. I am a bit more of a skeptic with anything new, I have been waiting to get one and thrash it a bit first. But it is time to get the word out, this new motor is great. I plan to put it on a pedal e-bike, it is a real waste of some of its virtues on something like my no-pedal chopper. On a pedal ebike I will take advantage of an 8 speed cassette and freewheeling. But the old e-chop makes a good test mule nonetheless. And it looks cool. I am working with the Infineon team on the controller. I wont offer it as a BMC compatible controller just yet. I do have the wiring figured out of course, and it does work, but needs a tweak or two I think.

As for efficiency, I took it on a 51 mile efficiency test today. It is an out and back. I kept my speed in the 16-18 mph range on flat ground. I figured out the efficiency sweet spot on the trip out by watching my speed, amp draw, etc. The trip out with a light tailwind took 8.5Ah, giving 3.0 mile/Ah (I will change to measuring Wh/mi in the future). On the way back, with sagging voltage and a headwind took 7.2Ah once I found the butter zone, giving 3.5 mile/Ah. Overall it took 1287Wh, or 25.2 Wh/mile on average. This is also on a par with the 5304, which is a good thing. The 5304 has proven a very efficient motor, even a lower speeds.

[Jerome Daoust]

From this message we learn that the New BMC 600 W weighs 8.9 lb.

How much does the 5304 weigh?

[dirtdad]

The 5304 is about 23 lbs. ebikes show a rear wheel build as 24.21 lbs, and a rim and spokes are a little more than a pound of that.

[Ypedal]

Hey DD !!! Thanks for the info !!! that's great !

I'd love to have you do the same test with a clyte 4 series, same voltage, same controller..

[GGoodrum]

Great stuff. It is good to get confirmation that you can get similar performance to the "benchmark" 5304, with a motor/wheel setup that weighs less than half as much. This also gives us a frame of reference for trying to infer how much of an increase in performance we might expect from the new 1000W model, assuming it to really is a geared design, as Brett reports.

With the stock wiring on the 600W, I think you'd be hardpressed to crank out too much more than the 45A the Infineon can put out, which is over 3000W. This is where the x5 series really has an advantage. Like many here, I've run my 5304 on my Townie at 72V/85-90A, with no problem. I melted the phase wires in a plug adapter (bullet plug to inline plug...) with one of Bob Mcree's modified 7240 controllers that peaked out at 104A, but the other one I used with an 90A limit worked fine. I remember seeing 6500W peak totals on the WattsUp meters before. I'm guessing the 1000W geared BMC motor will take more than 45A, but how much more, I don't know.

One other thing that will be interesting, will be to see how well these new composite gears hold up, after you two have had a chance to put some hard miles on the 600W motors.

-- Gary

[voicecoils]

Like many here, I've run my 5304 on my Townie at 72V/85-90A, with no problem. One other thing that will be interesting, will be to see how well these new composite gears hold up, after you two have had a chance to put some hard miles on the 600W motors.
-- Gary

What's your opinion on the continuous power handling of the X5, Gary? 6.5kW is impressive, but can it be sustained?

If so, I doubt the 600W BMC could handle the same. Still, for most eBiking applications I don't think such power is necessary

I'm quite interested in long term reports of the gears as well!

[getadirtbike]

The BMC has stronger pull in the range of say 20-30mph. They 5304 has more acceleration power at 30+. Most of the time in regular riding I do not feel a big difference.

Any idea which one is faster from 0-20mph?

The BMC phase wires are just too small to handle this kind of power for any significant amount of time and put it at a disadvantage. I am guessing they are 16 gauge? They ARE silver/teflon, and the harness coming off the motor is about 2 feet long and I have not shortened it. At the bottom of the big hill climb they were warm to the touch. By the top of the same climb, 1/2 mile later, the were too hot to hold on to. I think heat and resistance were a big factor on the hill climb.

Any idea of the comparative temperatures of the coils in either motor?

[GGoodrum]

Like many here, I've run my 5304 on my Townie at 72V/85-90A, with no problem. One other thing that will be interesting, will be to see how well these new composite gears hold up, after you two have had a chance to put some hard miles on the 600W motors.
-- Gary

What's your opinion on the continuous power handling of the X5, Gary? 6.5kW is impressive, but can it be sustained?

If so, I doubt the 600W BMC could handle the same. Still, for most eBiking applications I don't think such power is necessary

I'm quite interested in long term reports of the gears as well!

With larger gauge phase wires, like around 12-gauge, or so, I think the x5 would have no problem running 6.5kW all day long. The motor itself never gets hot at all, just the wires. The thing is, when do you ever need that much power continuously? Even going up a long hill won't use that much continuously.

[knoxie]

Hello

Good comparison, motor temps are very hard to detect on both motors, the coils are on the inside of the motor on the stator the magnets on the outside so temp transfer is very hard to detect, The BMC and the X5 coils can run very hot indeed it depends on power and usage of course, the BMC copes quite well even at power levels of 1500W or so but problems start to arise very quickly above that, the first thing to suffer on both motors is the hall sensors.

Quite a few people have found the hall sensors are very sensitive to high temps, the new motor is exactly the same as the new Team Hybrid motor, keyed rotor etc.

I have been using the X5 and the BMC for over 2 years now, the X5 is a much more robust unit at higher powers, it handles the higher power much better than the BMC, the gears on the BMC wear much faster on the BMC when you up the power, another thing that can suffer is the main drive bearing on the rotor, this is sadly the weakest part of the motor when being used at high power levels, the combination of heat and power can break the bearing, effectively locking the rotor, turning the wheel backwards with no batteries connected to the controller can diagnose this problem quite quickly.

The gears can be broken on the BMC if you use high power in combination with fast loaded starts, jumping and or hill climbs.

It should be fairly obvious from their physical size difference and build that the X5 motor is much more capable of reliably handling higher power levels than the BMC for sustained periods.

During the clash of the titans meeting we broke 2 BMC motors, one was down mainly to jumping but the other went under acceleration, that was a new 600W motor like this one, using steel gears with a keyed rotor, the motor was being run at 72V 35A, a few hard starts shredded 1 gear and broke the main rotor bearing.

I still like the BMC motor, love its weight and its acceleration however its not really built for the long haul, the X5 is heavy but it is built for the long haul, sure it could do with some improvements but its nearly there.

If the BMC factory actually listened more closely they could build a reliable motor at much higher powers than currently available, the BMC if used sensibly is a great motor, you abuse it and it will break, the X5 is much harder to break and if they fit better halls to them and or utilise a sensorless controller for them ALA Justins controller then I think you have a motor that will last you a very long time indeed.

Just my 2 cents worth as usual

Knoxie

[dirtdad]

Knox,

All good feedback thanks. It looks like BMC and Team Hybrid are starting to differentiate themselves. The motors likely come of the same assembly line with tweaks for each brand. While you may have had a new motor for Clash of the titans, it could not have been the new BMC, it would have had to be Team Hybrid or a prototype. Mark's presence there and steel gears make me pretty sure it was a Team Hybrid, no? Production 600W BMCs only appeared a couple of weeks ago. BMC specs the composite gears instead of steel, which they believe is a more durable set up, and probably took longer to get out the factory door.

As for durability, I am keeping this motor in full time use at 72V on my no-pedal daily driver. It encounters my test hill daily - around 700 ft climbing, carries a trailer load of bike parts, and usually gets about 15AH discharge. I am testing some batteries at the same time also. And some controllers.

I think thicker phase wires would fix a lot, including heated up hall sensors. Knuckles has discovered this with Bafang motors as well as others.

But ultimately the X5 is still the big Kahuna, esp on the top end. After running both on my eChopper, though, I think the BMC is better for pedal assist applications. The X5 @ 72V is verging on motorcycle motor territory. Being big, heavy, and having so much drag, I decided to lose my pedal drivetrain. I could not propel it more than a mile or two after the battery died anyway, and it had so much torque that I could rarely add enough power by pedaling. Pedal assist starts do save amps, but all of the complexity of a pedal drivetrain was not worth it for me. Now that I have the geared BMC I am thinking differently. But I need a new frame for that project at this point.

[knoxie]

Hi Dirtdad

I had the 600W BMC a year ago in fact I had 3 of them, there is a link to it on here and a youtube video, I had 3 variants as well at different RPMS, the steel gears were added in after we got them as the composite gears dont last very long at 72V, Clive was climbing a hill using the composite gears running 72V and it chewed the gears.

The factory are not exclusive and they did upgrade the phase wires on the 600W motor, but they didnt really beef it up that much, they need to recast and make the motor bigger in order for it to work as well as the X5. I dont notice that much drag on my X5? 5304 in a 26 inch wheel, I still love the Puma and think it makes an ideal motor for peddle assist, I just wouldn't run one for extended lengths at 72V as it will fail its jut a question of when and never is a good time!

As far as exclusivity goes all they do is stamp a different name to the HUB, the motors are the same otherwise they will tell you they are making them just for you but they arent, they are running a business and will sell to anyone willing to pay in qty for a box full of motors.

I dont know of any Puma or BMC motors that have been run hard at 72V for any length of time, my BMX only ever sees 37V and sometimes 60 but not for extended periods, the other ones that have or did run at 72V have had issues and now run only at lower powers.

I think its fair to inform folks that this is the problem with them, in some ways my old videos should really come down as it doesn't help and folks may buy them thinking they will work however the videos are fun and I am not selling anything, Mark never warranted the motors at anything over 48V 20A for this reason.

My personal preference is the X5 after years of messing about, you get used to the weight they are pretty efficient and they just plain work and dont brake!

Thanks again for the input.

Knoxie

[dirtdad]

Knoxie,

I got the impression from your signature that you had run the BMC with 72V for an extended time. Well, no matter, I am doing that now. I may post some reliability follow ups later. But the factory does seem to agree with you, they don't like to sell more than 48V controllers to go with the motors, so neither do I, but there are always modders who are interested in what you can get away with.

[knoxie]

Hello Again

No the signature is just representative of the video kind of so people who see the video then come here know who I am. You can of course run the Puma/BMC at 72V but they just dont last very long if used for extended periods, doesnt look quite as cool in the signature

The first BMC motors came with a 37V 15A controller and the performance was pretty unremarkable, most people swap them out for xlyte or infinion of course and 37V 35A is a lot more respectable and a lot kinder on the motor. There is no doubt that 72V 35A is exhilarating on the Pumas and some have held up, Jozzers KMX seems to still be holding together but many havent and those that are a little heavy on the throttle or the bike have found them to be very easy to break

I think in time a suitably rated geared hub motor will surface, there is a market for one thats for sure, my concern with selling the motors is that folks will abuse them and then want repairs and or replacement under warranty, its not the motors fault in many respects as they were only ever designed to run at 250W, the fact that they break when running at high power levels is to be expected in many ways.

I still think they have a place and can be reliably run at 600W which isnt shabby at all and in fact is nearly 3 times over the legal limit here in the UK and almost up to the limit in the US, keep em legal keep em reliable!

Knoxie

[Ypedal]

Those BMC's look just like the eZee motors, made by the same people imo, and i agree with Knoxie on this one, you can push them hard but not harsh..

The gearless hub motors suffer no ill efects from bad throttle control compared to a geared setup.

Guys who treat the Ebike like a Motocross by blirping the throttle ( is blirping a word ? ) instead of rolling on smoothly and either staying ON or OFF but not constantly mashing it..

Just like pedaling by kicking the pedals forward and backwards in half turns ruins freewheels.. and shifting while pedaling hard up hill ruins derailers..

[knoxie]

Hi Y

Yes good analogy there! the way they are ridden also is a big factor, a lot of folks have had problems that have largely stemmed from the fact they never ran torque arms as well, motors spinning and ripping cables apart. I think after you have owned and fixed your own rides you tend to treat them with more respect and they in turn reward you with hours of fun and reliability.

Not all none geared hub motors are faultless either though and can still fail if abused, Jozzer has just finished repairing a load of 4 series motors that were being used with big lead acid batts on electric rickshaws, they abuse them pretty badly whapping open the throttle and running lots of chubby tourists about the place, I think on 6 of them they got so all the magnets came un stuck and the motor just grinded them round.

He split the motors and used some high temp high strength adhesive on them which seems to have done the trick, again the Chinese dont over engineer anything, they shouldnt have to either in reality and I do think a lot of what they sell is pretty poor quality but then it is cheap, you want high quality you have to pay.

I think the X5 takes a lot of beating and I dont see any competition for it out there if high power and combined reliability are your over riding concerns. Ask Justin! his one took him a very long way indeed.

Knoxie

[dirtdad]

I believe the correct term is blipping the throttle. Urban dictionary has other ideas, however. Ok, no bliping or blurping the BMC. Got it.

[GGoodrum]

I still think a geared hubmotor could match a typically over-powered x5 setup, but maybe the 600W model is not the one. The new 1000W model, if it appears, sounds like it would handle the higher power, from an electrical point-of-view, but the unknown is still going to be the gears, I think.

In general, I think adding gearing to a smaller motor can go a long way towards making up the torque advantage that a bigger motor, like the x5. For instance, running a Cyclone 1000W motor through a Nexus 3-speed hub produces a pretty amazing amount of torque. I had a 5303 on my 20" Mariner folding bike, which ran on a 24s4p 72V a123 pack. It had blistering performance. I've since replaced this setup with the 1000W Cyclone, which comes with a 48V/55A controller. With a 16s4p a123 pack, this puts out about 2700W peaks. There is about a 7:1 gear reduction to the front sprocket, pretty much 1:1 to the back sprocket and then the Nexus hub is 1:1 in 2nd, 0.75:1 in 1st and 1.33:1 in 3rd. Even on 48V, this has more torque in 1st gear than the 5303 on 72V/50A. It also has roughly the same top-end in 3rd gear. The point is that gearing can certainly help narrow the performance gap between smaller and larger motors, but in the case of the BMC's the weak link seems to be the planetary gears.

-- Gary

[Microbatman]

DirtDad Great info thank you for the test.


What are the changes between the old 400W BMC and the 600W BMC?


Are they the same casing?

[Knuckles]

All I can say is "METAL GEARS and BIG FAT PHASE WIRES"

PMGR is more BANG for the MASS of motor but DD rules for top speed on the FLAT.

IMHO

[dirtdad]

What are the changes between the old 400W BMC and the 600W BMC? Are they the same casing?

The differences are improved materials and construction: composite gears, silver/teflon phase wires, bigger stronger magnets, tighter tolerances, etc. The casing has the same external dimensions. But much of the shell was simply made and unnecessarily thick. So it was thinned out in non-structural areas. The end result is a motor that is the same weight and size that delivers more power. The differences may not sound like they add up to much, but the proof is in the results, this little motor really flies.

[dogman]

Great thread guys! I think what a lot of us want to know is how the new gears hold up. All metal is a good solution, especially for a motor to be used off road, like a motorcycle. But for my 29 miles a day, a plastic gear that doesn't go to peanut butter so easy is sounding like something I'd rather listen to for two hours a day. If the new gears can take 72v for a substantial length of time, say 500 miles, I think I'd be confident to run one at 48v.