climbing ability bafang bbs 750 vs mac 12

Hello, I cant decide if I should buy a mac 12 or a bbs 02 750w.I will use the motor on max 20% hills.the hills are short max 0,5 km(pavement).if both run at 48v 25 amp which one will be the fastest in hill climbing.I dont need topspeed more than 25 kmh

Anyone tried both motors?

All I can tell you is that the BBS02 750 Motor will do it. Probably not fast, and you would need to be in granny gear, but it will do it.

ON the plus side, you won't need 72V or more to get the BBS02 up to 30 mph in high gear on the flat, once you conquer that hill.

+1 on mid-drive. You also keep the original weight on the rear wheel.

completely depends on the grade of the hill. At more than 15% the MAC will simply stop. The middrive will still do it. On a 5% hill the MAC will be faster.

crossbreak said:

completely depends on the grade of the hill. At more than 15% the MAC will simply stop. The middrive will still do it. On a 5% hill the MAC will be faster.

Click to expand...

Where do you have this information from?
At ebike ca simulator the Mac 10 (Ezee V2) will do 8.2 mph (13 kmh) at 15 % with a total weight of 287 Ibs(130 kg)
same weight 20%,a Mac 10 will do 4.4 mph (7kmh)
This is a mac 10 the Mac 12 will be faster maybe 10 khm on 20% .Can the bbs do this on throttle alone at same speed and with a 287 ibs (130 kg) total weight?

A MAC 10 on 30% hill 48v 30 amp

http://www.youtube.com/watch?v=RIHJPOL3_HQ

1boris said:

A MAC 10 on 30% hill 48v 30 amp

http://www.youtube.com/watch?v=RIHJPOL3_HQ

Click to expand...

Forgot about that video, is that really 30 % ?

I have my doubts the mac could do that all day every day, but it will still consume a lot more power than for instance the bosch crank drive which is about 500 watts but granted the bosch will make you put effort in.

I'd like to test a 12 t on 60 volts .

I would like an opinion from someone who have tried them both.Mac 12 48v 25 and a bbs 750w

1boris,

""I would like an opinion from someone who have tried them both.Mac 12 48v 25 and a bbs 750w"

I have a geared MAC350 hub motor on my bike, running through the gears. I can run it just like in the wheel by running it in 5th gear. This is a one to one ratio.

I can tell you the difference, and you can too, if you go back to the simulator and do a little more figuring.

If you look again, you will see that the V2 is running at 62.3% efficiency at 8.2 mph...141.8 Wh/mile. Now, instead of the 26" wheel, plug in a 16" wheel...equal to me running in second gear. You will see the V2 running at 79.5% at 10.4 mph...111.8 Wh/mile!! QED

Re that video, it's definite proof the Mac will run up a hill that steep, for about a minute, given enough watts. But try that over and over, and I think you will find that motor getting hot. The motor is definitely not in efficient rpm in the vid.

Mid drive for the win, if you need to climb that kind of hill more than once or twice in a ride.

dogman said:

Re that video, it's definite proof the Mac will run up a hill that steep, for about a minute, given enough watts. But try that over and over, and I think you will find that motor getting hot. The motor is definitely not in efficient rpm in the vid.

Mid drive for the win, if you need to climb that kind of hill more than once or twice in a ride.

Click to expand...

I completely agree. I wouldn't run it over 500 wats on long steep climbs, A mid drive should have a lot more torque at that power also and you get torque in every gear, great for slow steep trails also.

If the bafang is anything like the bosch then it will never get hot, the casing has never felt even warm after a long steep clump 23%+ and it will do it all day long or until your battery runs out.

One reason I got the bosch was because of its smoothness and the ability to take it up the steepest hills I can find without burning and being efficient. At 500 watts it can climb all I need and there is a more powerful one now.

If the bafang is as good then you'll never need more, if money isn't an issue then a 1600 watt ATF kit would be much better again.

You mean this video?
[youtube]RIHJPOL3_HQ[/youtube]

The bbs will do that all day in the right gear.

just simulated, the BMC Trq (think this is a code 12? ) takes the 15% hill at 6.8kph.. wouldnt have thought that. But at 20% it simply stops with only 48V/25A

The hotter it gets, the earlier it will stop. Guess if hot, it wont take the 15% anymore

The video is no real "test". I can climb that hill completely without any motor if i pedal all the way up :lol:

It's a pity the motor simulator doesn't include crank drive motors.

The motor simulator says it will stall on 15% and 15 amp controller that's about 500 watts. 36 V 15 amp controller. The bosch will climb that all day @500 watts, and I'm sure the Bafang also.

Granted the Bosch requires hard peddling above 20% at max power at 15% it's no problem at all.

I bet the mac did it in the video but it was running 1500 watts so probably 36v and 40 amps, no way a mac will tolerate that for long at such a slow speed. 500 watts I bet it would require ultra hard peddling, or it would just stall.

So why buy a motor that will need more power to climb when the crank drive will do it with a smaller lighter battery, you can use the newer nmc packs for even smaller size and weight. The Bosch pack using Panasonic cells for instance 400 watt hrs and about 2.4 kg. With the mac you'd need more than twice the battery to cover the same distance for hilly routes that is.

I have mid-drives (GNG gen 1 and 2 plus DIY Bafang) and hub-motors. Mid-drives are not nearly so relaxing to ride. You have to keep changing the gears. Also, you can smash your drive-train when you try and change down going up steep hills. Crank-drives can climb very steep hills if you select the right gear first and you have low enough gearing, but for the very slight theoretical gain in speed and efficiency, it's not worth it compared with the simplicity, comfort and sheer grunt of a 500w geared hub-motor at 30 or 40 amps. Keep your crank-drives for people that ride for sport, which is their forte.

The low powered ones are still useful compared with low-powered hub-motors because they don't stall out like a low-powered hub-motor will.

I still haven't been able to prove that a crank-drive uses less battery than a geared hub-motor. I have lots of hills where I live. Some are 30%. I've tried every type of motor on my hilly 35 to 40 mile rides, and I can't find a significant difference in efficiency. It's easy for me to do back-to-back comparisons because my friend is the same weight as me, and we ride together at the same speed. We swap the bikes around.

A 20% hill is nothing for a 12T MAC with 48v and 25 amps. That video shows it on a 30% hill.

d8veh,

"I still haven't been able to prove that a crank-drive uses less battery than a geared hub-motor. I have lots of hills where I live. Some are 30%. I've tried every type of motor on my hilly 35 to 40 mile rides, and I can't find a significant difference in efficiency."

If you average 25-30 mph on a short ride like that, there is no point to a mid-drive, and at 15 mph there is no point to a motor for those distances. So yes, mid-drives have a sweet spot.

d8veh said:

A 20% hill is nothing for a 12T MAC with 48v and 25 amps. That video shows it on a 30% hill.

Click to expand...

Why do it with 1500 watts when you can do it @ 500 for a crank drive ? unless of course you don't want to put effort into peddling.

I can't see a mac pulling 1500 watts at slow long climbs doing it all day compared to the crank drives. Though I would like to try it with a 12T.

I know you prefer even the bafang geared hubs to the Bosch but as I told you before the Bosch prefers a faster cadence to output maximum power, the torque sensing software must be designed so that when it senses a faster Candace it should mean you're going up a steep and so then should apply max power. And to be honest it works brilliantly.

I don't find gear crunching much of an issue, as soon as I stop peddling the motor turns off, I just back off the peddles a bit and change gear, not an issue and I haven't broken gears yet.

The Bafang should work better for those who want to put a lot less effort into cycling. And it is 750 watts V 500 for the Bosch. I believe the 750 Bafang has 90 Nm torque V the 2013 50 Nm Bosch ? The Bosch 2014 I think has 60 Nm torque.

I agree a geared hub is fine for most people but the crank drive will climb everywhere where as in my experience a hub won't. I find it amazing the Bosch will climb what a pie II @ 3kw could and not much slower, @ 500 watts and above all it was cool at the top and the Pie roasting. And the pie consumed much, much more power. This was 23% +, I must try find the actual grade I think it's steeper.

I think for the steepest of hills and slow steep trails the crank drive is the way to go, for normal riding normal hills and for higher speeds then the geared hub will do fine. I do find the crank drive much more efficient than the hub. I've never used such little power on my cycles with hubs on long cycles, but if you're happy enough to buy and carry around a bigger battery then I see no advantage to crank drive.

Another advantage with crank drives means you don't have to play with torque arms.

o00scorpion00o said:

d8veh said:

Another advantage with crank drives means you don't have to play with torque arms.

Click to expand...

Click to expand...

Don't get me started on torque arms. I just sent my first CAD file to the laser cutter for my DD Hub build.
Also with a Mid-drive, you don't have to settle for cheap (DNP) or poorly-geared freewheels. My 11-32T 8-speed cassette is a great gearset to complement my BBS02.

crank drive for LOTS of hill climbing. Otherwise geared

I would not want an 11T on my Middrive bike. I throw out everything smaller than 13T...they exist only since "bike mafia" wants the chains to wear within <1000km :lol:

The Bosch motor is relatively low power and torque compared with a GNG or 500w Bafang CD. Like I said before, when you have low power, a crank-drive gains an advantage in a hilly area. A 12T Mac at 48v and 25 amps would annihilate a Bosch in any hill-climbing and is in a totally different class of power, so it's not really valid to compare it.

People keep saying that the Mac will overheat if it repeatedly has to climb a hill like the one in the video, but come on: Where realistically do you have to repeatedly climb hills like that? IIRC, OP was talking about occasional 20% hills. It would be different if he lived in the Alps or Rockies. I hope he can read through these posts what's relevent for him. IMHO, for him. The MAC wins regardless of what's better for other people.

d8veh said:

The Bosch motor is relatively low power and torque compared with a GNG or 500w Bafang CD. Like I said before, when you have low power, a crank-drive gains an advantage in a hilly area. A 12T Mac at 48v and 25 amps would annihilate a Bosch in any hill-climbing and is in a totally different class of power, so it's not really valid to compare it.

People keep saying that the Mac will overheat if it repeatedly has to climb a hill like the one in the video, but come on: Where realistically do you have to repeatedly climb hills like that? IIRC, OP was talking about occasional 20% hills. It would be different if he lived in the Alps or Rockies. I hope he can read through these posts what's relevent for him. IMHO, for him. The MAC wins regardless of what's better for other people.

Click to expand...

A mac as you said on 48 v 25 amps would indeed annihilate the Bosch at nearly 3 times the power, not exactly a fair comparison really is it ? The Bach s 500 watts not 250.

The bosch will climb way better than the mac at the same power. Why carry a bigger heavier battery if you don't need to ? Same applies to the bafang I'm sure. The 750 bafang is supposed to have 90 nm 40more than the bosch. Don't know what that is like in reality.

I don't think you're such a great fan of the bosch because it makes you put in effort and you are not a fan of putting effort into peddling if I remember correctly ?

I have tried the bosch motor.and tested it for about 30 mins in diffrent hills.And I was not impressed.My neo cross which has the same power and a hub motor is better in hill climbing.And much better overall.So I already know that a mac 12 would be better at the same power.
I have a bbs 500w 18amp .It could not drag me up a 20% hill alone.total weight 130 kg.But the motor is a little overgeared.But I now have a 20 amp new controller that is supposed to pull about 25 amp.I havent tested it yet.And I ordered an upgrade mac 12 kit 26" wheel yesterday.So I will soon be able to compare the bbs vs mac myself.But I get the feeling that the Mac 12 motor is a little underestimated here.I will soon find out Thanks for all the replys

I don't believe you remember correctly. Everything I've read by D8veh indicates that he is an expert on and connoiseur of small geared hub motors, providing a wealth of knowledge to small motor afficionados like myself. Ergo he must like pedalling, I assume, like myself.