BPM Bike Kits?

[Confab]

Hi all,

I'm considering converting my hybrid bike (Carrera Crossfire) to an ebike, but there's so much choice that it's hard to make up my mind. I really don't want to spend more than €600 (inc shipping) total. The BPM 350w kit seems fine, but the battery is a concern. Can I go for Li-ion or is LiFePo4 far, far better? I'm thinking of a 15Ah Li-ion or a 10Ah LiFePo4 (cost reasons).

My commute to work is 10km each way in traffic averaging about 20kph, very few hills and I'm about 100kg.

Thanks.

 

[dogman dan]

Give us a link, or a pic, or something. Assuming it's a bafang bpm motor, it should be fine for your needs.

In general, the most foolish thing a guy can do is try to economize on the battery of an ebike. I keep recomending a 15 ah pingbattery over and over and over. Not the only option of course. But a lot of cheapie batteries have ended up being a turd in a nice looking metal box.

 

[Confab]

The kit is: http://www.bmsbattery.com/ebike-kits/345-bafang-350watts500watts-bpm-motor-e-bike-kit.html

Are are there any reliable batteries that are cheaper than the Ping?

 

[miuan]

This one, assuming you already order from them.
http://www.bmsbattery.com/packs/154-36v-12ah-38140-lifepo4-battery-12-cells-ebike-battery-pack.html
Make sure to order the one with 60A peak current BMS. You may not use the excess power in near future, but it will run cooler and more reliable than the basic 30A version.
Also pay attention to the speed setting. Buy 201rpm if you want slow EU road legal ebike (15mph), or 393 rpm for fast 25-30 mph riding.

 

[Wurly]

Why a BPM hub motor? very few hills you say?
A smaller 36V 250W hub motor laced into a 700c wheel would assist to 18mph no problem, you wouldn't need such a big battery either, but a 10ah would be about right.BPM's are quite power hungry so you would be looking for 15ah...more money!
http://www.bmsbattery.com/ebike-kits/393-bafang-250watts-front-driving-qswxk-motor-e-bike-kit.html
If you needed more speed run the same motor at a a higher voltage.
Don't forget shipping on the prices you see, that isn't cheap these days.

 

[d8veh]

I've got 3 bikes with BPM motors and they make a nice workhorse. I also have a Cute Q100 on my light-weight folder, on which I can cruise at over 20mph (if I want) - and I'm quite heavy at 100Kg.The Q100 is a lovely motot: It's very quiet and smooth. I've just taken delivery of a Q128, which is smaller than a BPM and bigger than a Q100. I think this might be a good solution for a lighter bike like the Carrera Crossfire. I'm guessing that it will be similar to the Q100 but with more power. The BPM needs a fairly heavy battery and is a heavy motor for a light bike, and I think this will spoil the ride a bit. Whatever you get, although quite heavy those Headway batteries that Miuan mentioned can give a lot of current, have a long life, are robust construction and are relatively cheap. I have one and I'm very pleased with it. Forget the normal LiFePO4s and LiNiCoMn ones, you'll soon be wanting more power. They're fine for 15mph with 250w motors, but you need a big one for more than that. Also this one is not too wide, so you might be able to fit it in the frame triangle.
http://www.bmsbattery.com/packs/154-36v-12ah-38140-lifepo4-battery-12-cells-ebike-battery-pack.html

 

[Confab]

Thanks all, I'm just about to order the BPM 350w kit with the Headway 36v12Ah battery from BMSBattery. I'm also getting a pair of torque arms, 2 x thumb throttles, 2 x 240w chargers, an extra KU123 BMS and finally an extra pair of Ebrakes. That will cover most eventualities. Any opinions? Might get the WattsUp meter as well.

The catalyst was my first ride on an ebike (some model of Giant Twist) on Saturday. What a revelation! 28kph without a problem, and that's a standard 250w motor. Absolutely amazing.

 

[motomech]

Deffinately the '201" motor with those 700cc wheels.
You will also need a DNP 7-speed freewheel.
The EV Falcon frame bag would be ideal for that triangle.
Take great care in mounting the motor/wheel. You may find the BMS Battery torque arms are not easily adapted to your drop-outs. Look at the different styles available from Ebike CA or some custom ones might have to be made.
Even @ 36V, the BPM has considerable torque, so locating the motor axles securely is of prime import.
The drop-outs on that model do not look overly strong to me.

 

[Confab]

Deffinately the '201" motor with those 700cc wheels.
You will also need a DNP 7-speed freewheel.
The EV Falcon frame bag would be ideal for that triangle.
Take great care in mounting the motor/wheel. You may find the BMS Battery torque arms are not easily adapted to your drop-outs. Look at the different styles available from Ebike CA or some custom ones might have to be made.
Even @ 36V, the BPM has considerable torque, so locating the motor axles securely is of prime import.
The drop-outs on that model do not look overly strong to me.

It'll be a front kit rather than a rear. A frame bag draws way too much attention to the bike imo. Thanks for the dropout recommendations, good idea. Finally, why should I go for the 201 rpm motor? I don't really know a huge amount about ebikes but surely 393rpm is faster and better?

 

[miuan]

You already know the speeds you can expect. Pick your choice.

 

[motomech]

Deffinately the '201" motor with those 700cc wheels.
You will also need a DNP 7-speed freewheel.
The EV Falcon frame bag would be ideal for that triangle.
Take great care in mounting the motor/wheel. You may find the BMS Battery torque arms are not easily adapted to your drop-outs. Look at the different styles available from Ebike CA or some custom ones might have to be made.
Even @ 36V, the BPM has considerable torque, so locating the motor axles securely is of prime import.
The drop-outs on that model do not look overly strong to me.

It'll be a front kit rather than a rear. A frame bag draws way too much attention to the bike imo. Thanks for the dropout recommendations, good idea. Finally, why should I go for the 201 rpm motor?I don't really know a huge amount about ebikes but surely 393rpm is faster and better?

It'll be a front kit rather than a rear

You haven't said if you have a Crossfire I, II o r III, at any rate, the BPM is a lot of motor for any of those forks, too much, IMO

A frame bag draws way too much attention to the bike imo.

And the big motor on spinly forks won't? People don't know there is a battery in the bag and they don't give it a second thought. So what's the alternative? Mount that heavy pack on a rack up over those tall wheels. There goes the handling.

I don't really know a huge amount about ebikes but surely 393rpm is faster and better?

Perhaps, if you had the platform to ride safely over 25 mph, but you don't.
Basicly, that's a cheap [but decent] bike. Crossfires aren't known for strong brakes and at the speed a 393 BPM will take it, you might as well drag your feet.
And with no suspension, speeds approaching 30 mph will rattle the fillings out of your teeth.
With that bike, you would be well advised to keep the speeds under 25 mph and if you are set on a frt. mount, you should consider a mini-motor.
The best one would be the MXUS from Cell_man, but if you ordered your battery from BMS Battery, you would have to pay shipping twice from China, raising the costs.
For that bike using stuff from BMS Battery, the 201 BPM. rear mounted and the battery pack in the frame is far and away your best option.

 

[Confab]

All good points. A 201 rear mount is sensible, as is a framebag. Thanks for that.

 

[motomech]

You will love the EV bag, everyone who has one does. They are so well thought out, with built-in "eye holes" for the wires. And with the large area your bike has, you can pull it really taunt, making it look decent.
Hang on a minute before you pull the trigger and I'll see what the Ebike Ca simulator says about you top speed.

I haVe a hopp'ed up mini in the front in the frt. of my bike, mounted on really high quality forks, and at times, it can be a real handful. On any surface other than dry pavement, it really wants to spin.

 

[alfantastic]

Deffinately the '201" motor with those 700cc wheels.
You will also need a DNP 7-speed freewheel.
The EV Falcon frame bag would be ideal for that triangle.
Take great care in mounting the motor/wheel. You may find the BMS Battery torque arms are not easily adapted to your drop-outs. Look at the different styles available from Ebike CA or some custom ones might have to be made.
Even @ 36V, the BPM has considerable torque, so locating the motor axles securely is of prime import.
The drop-outs on that model do not look overly strong to me.

It'll be a front kit rather than a rear. A frame bag draws way too much attention to the bike imo. Thanks for the dropout recommendations, good idea. Finally, why should I go for the 201 rpm motor? I don't really know a huge amount about ebikes but surely 393rpm is faster and better?

I don't quite understand why you think a frame bag draws way too much attention. Is that compared to a whacking great battery hanging off the rear end, upsetting bike balance and handling?
Any police behind you will see that easily, but your legs will cover much of a frame bag whilst riding, whether pedaling or not.
Traction will be an issue in the wet with the set-up you are planning. Dangerous if you plan to ride on the road with other motor vehicles. Also dodgy on dirt/gravel cycle paths IMO.

 

[motomech]

Why don't you wait until D8veh chimes in again. He has build both frt. and rear mounted BPM Ebikes. This is a pic of his frt. bpm on a Giant bike;

You will note that he fabricated special torque arms that are welded to the forks.
At any rate, his input would be invalueable to you, so hang on a bit.

And yes, he uses rack mounted packs, but his are Lipo[I think]and are small and relatively light.

 

[Wurly]

My vote is for a rear mounted BPM as well. I think they are a bit too much for front forks. It's more of a hassle to fit a rear hub but you won't regret it.
I wouldn't like to advise over the rpm motor you intend to get, but a 393 in a 700 rim will be pretty fast, but then you are only on 36V and you can always connect a speed switch to slow it down. I've got a feeling that 201 might be a bit slow for you.
You can always fit front suspension if your bike doesn't have it.

 

[d8veh]

Recently I found out that the 201rpm motors will do about 21 mph in a 26" wheel if you use position three on the three-speed switch with the KU93/KU63 controllers. You don't need to fit the switch. Just join the green and black wires after cutting off the connector. A 700C wheel will therefore do about 22.5 mph - if that helps. Regarding front or back motor, they both have advantages and disadvantages, but front wheel motors normally take a bit more engineering to fix them in properly. It's not a good idea to run a BPM at full power in spindly forks, and it's no big deal to change forks to ones that are more suitable. I just fitted a BPM to a bike with Zoom triple clamp forks that had 5mm steel drop-outs, so no reinforcement was necessary. The forks, although heavy, work quite well, and they can be found really cheap. Not sure if these are the same ones, but they're certainly similar:
http://www.swapz.co.uk/swapz/2335762/zoom_triple_clamp_mountainbike_forks/
I'm now using the 12aH Headway battery with one of my BPMs, and I find it much easier than lipos whilst still being able to give enough current. It still fits nicely in a football boot bag on the rack leaving enough room for a controller on top.
http://www.bmsbattery.com/packs/154-36v-12ah-38140-lifepo4-battery-12-cells-ebike-battery-pack.html
I think this would be about as heavy as you'd want to go on the back with a rear motor, any bigger would be better fitted in the frame triangle.
I'm still experimenting with the Q128. I've now soldered the shunt for more amps, which has improved its climbing power, but It's not performing like a scaled up Q100 like I had hoped, so I'd cross that one off the list for any future projects.
The stuff from BMSbattery isn't too expensive. If you try a motor and it's not suitable, you won't lose much by selling it on Ebay and buying another one. My feeling is that the 328/293 rpm motors will be too fast for 700C wheels, so that only leaves 201 rpm from BMSbattery. EVassemble.com sell the code 10 BPM last time I checked, but you have to build your own wheel, or you can get something from Cell-Man. The main problem is that now there's too much choice and you can't have power without weight.

 

[motomech]

What about the 201/700cc combo @ 48V?
That would put him in the 26-27 mph range.

 

[Confab]

I went ahead and ordered:

A Pair of EBike Torque Arms - Size : M12 x1
36V 12Ah 38140 LiFePO4 Battery 12 Cells EBike Battery Pack - Discharge Current : 30-60A x1
EMC-240 Alloy Shell 240W LiFePo4/Li-Ion/Lead Acid Battery EBike Charger x2
KU123 500W 12Mosfets High Speed Controller - Voltage : 36V x1
Brake_Grip x1
Thumb Level Throttle x2
BPM 36V350W Front Driving Bike Conversion Kit - RPM : 201 x1

I'll swap out the fork and get a rear battery bag, other than that should be fine. Thanks all for your very useful opinions.

 

[Confab]

Does anyone know how long it takes BMS Battery to ship? The order is marked as 'Testing' for three days now.

 

[dnmun]

Does anyone know how long it takes BMS Battery to ship? The order is marked as 'Testing' for three days now.

'Testing' means they are seeing how patient you are. testing you. not the battery.

in the meanwhile they are waiting for someone to build the battery for you and deliver it to them. they will ship it when they get it. like fresh produce or big macs, they wait until you order it.

 

[sacko]

Mine took exactly 3 weeks to get here from placing the order.

2 weeks @ BMS Battery
1 week with FedEx.

 

[Confab]

Thanks guys. Stops me worrying about the order. Now to get a rack and battery bag. Halfords stuff should be fine, right? I want to be able to disconnect the battery at work and at home.

 

[d8veh]

Two to three weeks is the norm now. It used to be five to six weeks. The longer it takes the better because you're more likely to forget what you orderd so you won't be so surprised when you didn't get what you ordered. There's normally a surprise element in what they send. You can't go by what anybody else got or the description in the website; however, I've never been disappointed with what I got. Last I heard, they're shipping the code 13 motor as 201 rpm, which is probably better for what you want. Mine does about 22mph with a 36v Ping battery at about 40v. Good to see that you didn't order the three speed switch because there was no connector for it on the last Ku123, which is now KU120. If you get the three speed switch contrtroller, you can join the wires to get a top speed of about 25mph.

Don't forget to let us know what you get when it arrives.

 

[manneokoko]

Im about to order a similar setup as you, and i have a couple od questions:

Why the extra chargers? there is one included in the conversion kit.
Why the extra brake grips and throttles, also these are included in conversion the kit?
What will the difference be with the 500W controller compared to the A 450W 9Mosfets universal controller included in the conversion kit?

Would the same package be suitable for a standard citybike with steelfork Like this one:

I went ahead and ordered:

A Pair of EBike Torque Arms - Size : M12 x1
36V 12Ah 38140 LiFePO4 Battery 12 Cells EBike Battery Pack - Discharge Current : 30-60A x1
EMC-240 Alloy Shell 240W LiFePo4/Li-Ion/Lead Acid Battery EBike Charger x2
KU123 500W 12Mosfets High Speed Controller - Voltage : 36V x1
Brake_Grip x1
Thumb Level Throttle x2
BPM 36V350W Front Driving Bike Conversion Kit - RPM : 201 x1

I'll swap out the fork and get a rear battery bag, other than that should be fine. Thanks all for your very useful opinions.