Which electric bike motor is best??

  • By 7053361902
  • 02 Nov, 2017
Bosch CX Performance mid drive

Bosch, Brose, Suntour HESC E45, Bafang BBS 02

Here's a picture of my favourite drive system. Bosch CX Performance paired with a 500 Watt Hour battery.

So many choices - and they all must be the same, right? Mostly 250 Watt or 500 Watt...legal limit is 750 Watt...bigger must be better right?

Absolutely not!

There are a number of other factors to consider.

First and foremost is nominal output vs actual output.

Bosch quotes a nominal output of 250 Watt for its CX Performance line - but it's actual sustained output is about 540 watts.

Brose quotes a nominal output of 250 Watt (and 350 Watt for Speed Pedelecs/28 mph) but really it kicks out 340 Watts.

Suntour quote 450 Watt for its HESC E45 system but really it kicks out 750+ Watts.

Bafang quotes 750 Watt for it's BBS 02 mid drive, but you can plug it into a laptop and go 1,300 Watts.

Conclusion - nominal output is meaningless.

Second: Is this going to affect my range?

Yes, absolutely. The more power you are sucking out of the battery the faster it will deplete, and not in a linear fashion. Higher strain on the battery means higher heat. It will deplete faster than just the increase in wattage suggests.

Plus there's speed. At 28 mph you need twice the power to push through the air as you do at 18 mph - so your effective range halves.

But! There's always a but...

What about efficiency?

Brose Mid drive...such an elegant design...
Here's a pretty picture of a Brose mid drive. 350 Watts is plenty of oomph to cruise around. Combine it with a mid drive and some excellent software and you end up with the best range package I've seen. Genuine 60 or 70 miles.

So what about that fabulous Bafang! 1.3 KW!! Well that level of output kills your battery in about 20 minutes. Unless you hit a hill, in which case things are going to get very hot. Great power, but seriously curtailed range. It's not a very efficient system...even if you turn the power down...but fabulous for the home build tinkerer! I run one on my dog walking bike and love it. 

The Bosch at 540? Super efficient. Gets great range considering the power output. Joyous. Slight whine...

The Bosch powered bike goes twice as far as the Bafang at the same fairly high speed, even with a smaller battery.

Third - All three above are mid drives....what about a hub drive?

Down below there's a picture of the Suntour HESC E45. It says 500 Watts on the side, but it also says 48 Volts by 15 Amps. So 720 Watts then. But actually fully charged it's 54.6 V x 15 A = 819 Watts. But it's a hyper efficient internally geared motor, spinning lord knows how fast, and it can do 25 miles at 25 mph. Which is outstanding.

There's some other great stuff in hubs...but  a non-internally geared hub on a hill turns very slow. Slow turns plus hill = high amps = high heat = high battery consumption.

Magnum's Das Kit 500 Watt is another great example of an internally geared rear hub (fast internal spin = efficient).

But internally geared rear hubs can make some noise - slight high pitched whine.

Big ol' Stromers and Specializeds use nice rear hubs that aren't internally geared. Not very efficient.

Also you can't use suspension with a hub.

That being said...it's hard to get decent fenders on rear suspension - though that is changing - so now we move into all sorts of other wrinkles!!

Conclusion: Mid drives rock. Bosch or Brose.
Bosch if you want a sports car
Brose if you want a long range, silent Merc
Bafang if you want to tinker.


Suntour HESC. 500 Watts. Really...?
Bafang BBS02 - home builder's favourite
Suntour E45 - only motor with heat sink!

Sleek eBikes Blog

By 7053361902 14 Nov, 2017
So you got a great deal on your eBike! You live in New York State and you got it from - ooooh...I don't know - let's say Wisconsin. Great deal! And you explicitly asked about the warranty. And the answer is yes! You have a warranty. It even says so on the dealer website.

So you get it shipped - local bike store sets it up - all is well! It's brilliant - you love it! You enjoy it so much you use it all the time! Two months in...it won't fire up. Battery in...press start...huh. Take the battery out, plug it back in, still nothing. Weird...why is that happening...

Not to worry! You have a warranty. So you ring the local bike store. Nope...they don't have diagnostics or training. So you ring the nearest dealer.

And the dealer says, "Sorry. Not my problem. There is no mechanism by which we get compensated for the work we do. You need to ship it back to where you bought it". Which is true. The Manufacturer will supply any replacement parts (and will sometimes compensate a dealer for repair work) but the local dealer is under no obligation to fix it. 

What now? Take it to bits and re-box it? Ship it back? Maybe the dealer where you bought it will pay for that. It's at least $200, plu sbox and packing materials. Then you have to ship it back to you once it's fixed. Another $200. Then rebuild it. Let's hope the fix works first time...$700 for shipping and time?

More likely Wisconsin guy will ring the local dealer and offer peanuts for their time to fix it. Because they made peanuts on the deal. Their business model doesn't work if bikes have to be repaired. Local guy says bite me. So now what...? 

If you buy local and it has a little glitch you take it back to where you bought it. Diagnostics run, problem identified, part replaced (probably had it on site already), no cost. Job done, zero hassle, happy customer. 

How about other things...? Setting up the shocks...? Checking torque settings and spoke tensions? eBikes have their little quirks. They need to be set up carefully. They are heavier, mileages are higher, forces are greater. (Shock too full or too low....pop!. Brakes not set up right and not properly bedded in...squeal - judder!). 

An eBike comes in an eighty pound box. You think it doesn't get dropped? Beat up by the courier? Has other stuff piled on top?

What if your brake rotor is slightly bent? Annoying slight rubbing sound - every time you ride - unless it's spotted and fixed...I always look for it. Rear derailleur got a bit bent? Gear change just not quite right...? Something happens on 1 in 5 bikes delivered in single boxes. I fix it before it goes out the shop, part of the business. 1 in 20 eBikes has an electronic component that has got hit, or was damaged, or needed a Firmware upgrade. I look for it, fix it before it goes out of the shop, part of the business. eBikes run high mileages, they can get little glitches. Easily & quickly fixed if you have access to someone with the right equipment and skills. Un-fixable if you don't.

If you want a local shop that's able to service your precious new eBike, bothered to get the equipment to do it properly, got accredited, etc - then there is a price to pay. As local shops we hate the interstate box shifters. The pile-em-high sell-em-cheap model destroys the local support infrastructure. And where does that leave us all? Where does that leave you a couple of years down the line?

Of course I'm biased. But that doesn't make it any less true.
By 7053361902 02 Nov, 2017
Here's a picture of my favourite drive system. Bosch CX Performance paired with a 500 Watt Hour battery.

So many choices - and they all must be the same, right? Mostly 250 Watt or 500 Watt...legal limit is 750 Watt...bigger must be better right?

Absolutely not!

There are a number of other factors to consider.

First and foremost is nominal output vs actual output.

Bosch quotes a nominal output of 250 Watt for its CX Performance line - but it's actual sustained output is about 540 watts.

Brose quotes a nominal output of 250 Watt (and 350 Watt for Speed Pedelecs/28 mph) but really it kicks out 340 Watts.

Suntour quote 450 Watt for its HESC E45 system but really it kicks out 750+ Watts.

Bafang quotes 750 Watt for it's BBS 02 mid drive, but you can plug it into a laptop and go 1,300 Watts.

Conclusion - nominal output is meaningless.

Second: Is this going to affect my range?

Yes, absolutely. The more power you are sucking out of the battery the faster it will deplete, and not in a linear fashion. Higher strain on the battery means higher heat. It will deplete faster than just the increase in wattage suggests.

Plus there's speed. At 28 mph you need twice the power to push through the air as you do at 18 mph - so your effective range halves.

But! There's always a but...

What about efficiency?

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