Another New E-bike thread

[jebike]

I posted about a week ago to get some info on some ebike kits. I've been reading a lot since then and I keep finding more and more options. I've narrowed my choices down to the following and was hoping I could get some advice on the benefits and weaknesses of each (what would you choose)? Also, if I'm missing a kit in the $300-$400 range (shipped) that would be better, please let me know.

The battery I've purchased is a V power 36v 20ah lifepo4, dimensions 290mm x 210mm x 100mm, Max discharge 40A, rated charge current 6 amps, rated discharge <12amps.

My goals are as follows: create a bike that can go 20-30mph and has a minimum range of 20miles with no pedal assistance. I live in the greater Seattle area and there are hills. I would also like to build something that looks as much like a normal bike as possible and is as quiet as possible. Safety is pretty high too, which is why I'm ruling out the front hub kits.

All the kits I'm considering are rear drive and I'm currently leaning towards the 8fun motor. It's the second cheapest and I like the size and stealthiness of it. From what I've been reading it appears to be pretty quick too and will also allow me to thrown on a disc brake in the future. I know with the em3ev kit that I will get a better wheel, but I'm not sure if there are any other benefits of that kit and the wheel motor is also much more visible? The yescomusa kit has the obvious benefit of being super cheap! It has a higher wattage also, I'm not sure if that necessarily equals a faster motor.

I still need to figure out if I should use a rear torque arm with these kits and if so, is one sufficient, or do i need one for each side? Where is the cheapest place to get one? I'm also wondering if the e bike brakes are really necessary for a kit with this type of power. I would much rather just have some sort of a kill switch and use the brake levers i already have. I'm also wondering about the best way to hide the controller. I'm going to have a rear rack frame bag for my battery, but I've read the controllers get to hot to be put in a bag. Anyone have any creative solutions?

So far my bike build specs are as follows.

Nashbar 26mtb frame
Xt v-brakes w avid levers
Fork: still deciding between a rockshox tk 28, surly 1x1, or on one chromo fork.
X4 rear derailluer and shifter / 8 speed.
110mm stem
Vans ODI grips
Wellgo pedals
Fsa headset
Scott 700mm mtb bar
Raceface evolve dh Ss crank w external BB
1.75 mtb tires, will upgrade to a larger volume street tire as money allows.

Kits I'm considering:

1) GBK - 8fun BPM motor kit 36V500W for electric bicycle

Motor code
10
RPM
216
Throttle with LED or not
Twist throttle without LED display
Wheel size
26"

2) em3ev DD

500W Direct Drive Kit
- Motor Speed Rear 275rpm (220rpm loaded, 36V)
- Controller Type 9 fet 30A (36-75V, IRFB4110)
- Wheel Type 20" Alex DM18 CNC
- Spoke Type Sapim Upgrade (Silver)
- Throttle Type Half Twist
- Ebrakes Yes

3) Yescomusa 36v 800w kit

Approx. 30 KPH top speed
Provides you with a whole wheel with tire, not just the tire frame Takes less than an hour to install
The kit includes motorized wheel, motor controller, battery charger, thumb throttle, power break lever, wire harness
Quiet and reliable brushless gearless hub motor
Motor specifications: 36V / 800W / 350RPM
High motor efficiency: 75%
Motor diameter: 245mm
Drive system has no moving chains or gears, no friction, more efficient, less chance to break!
Brake shuts off motor automatically, saves energy, improves safety!
Thumb throttle with 3 LEDs indicator lights
Battery charger for charging lead-acid battery
Durable 600D Oxford cloth carrying bag along with a zippered main compartment for battery
It's for bicycle only.

 

[dogman dan]

EM3ev dd kit would be my choice, Much better fit and more reliable controller. Easy to put a disk brake on it if you would like to later.

23 mph on your battery, you will have about 22 miles of range.

The yes kit is extremely similar, but with an earlier design motor. It's possible though, that the disk ready motors are now being sold at Yes. I just know they were the older design motor last summer.

If price is all that matters, the yes may be cheaper. But I'd send my money to EM3ev.

The other motor is very slow, and won't come close to your speed expectations.

 

[jebike]

Thanks for the info. Any recommendations on where to get a rear torque arm?

 

[tomjasz]

Motion seconded. Great stuff, great end price. International shipments require relaxing and letting 10-14 days be the norm. It's busy season, expect possible delays. The reward is the best of gear at the best in pricing. I'm thrilled with my purchase.


EM3ev has the torque arms.
GRIN TECH REV4 REAR TORQUE ARM $40
Ebikes.ca products I believe.

 

[d8veh]

That BPM kit from GBK will give you what you want, but the info isn't correct. A code 10 is 312 rpm, which is about 23 mph at 36v.

To keep your brake levers, you should get a pair of these cable sensors:
http://www.greenbikekit.com/hidden-wire-brake-sensor.html

With that kit, you can install the controller in a bag. It won't get too hot provided that it's not a thick padded bag.

You need one torque arm on the brake side.

http://www.greenbikekit.com/accessories/ebike-wheel-kit-parts/torque-arm.html

Don't use their clamp arrangement. It's unsafe. Do it like this. Either cut down and drill their tie bar or make your own. The metal is very hard. You'll need an angle grinder and cobalt drill, which is why it's easier to make your own:



You can get the same stuff from BMSBattery, except that BMSB have a better range of controllers. Their S12S or S12P with LCD are very nice. You have to order the LCD and wheel-speed sensor separately.

The DD kit might be better for you if you don't have hills and if you don't want to pedal without power from the motor.

 

[dogman dan]

If that BPM is faster, then it's still a good choice too. Perfect, we got it really narrowed down now.

Bottom line, all three will work fine. In some ways, it comes down to who do you want to get your money.

You saying a muxus dd motor can't go up a hill Dvh? I suppose 8-10% grade non stop for 10 miles, in a desert climate is not much hill? Sheesh, sure a weaker controller in the 1000w ballpark will struggle up 15% grade, but you don't see that much paved road above 10%. Some residential streets sure, but not a long road.

 

[wesnewell]

Welcome to ES****Do this before your first post or now (it's retroactive)*****
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. Once done, your location will appear in every post so you won't have people asking where you are ever again. This will help people help you. Example: Wylie, TX, USA. or just USA, but country as a minimum, and country is the most important. There are many cities with the same name all over the world. Without knowing what country you are in it's hard to make any recommendations. Thank you.
If you're un the US this would be my choice.
http://www.ebay.com/itm/Electric-Bicycle-48V1000W-LCD-Display-26-Rear-Wheel-Motor-Kit-E-Bike-Conversion-/291146654196

 

[jebike]

Thanks for all the information. There was another $15 bucks off on the yescom kit, which was enough to push me over the edge. I had my cart loaded up a few times at both Em3ev and GBK, but I could not justify the extra $150-$200. Hopefully, the gamble will work out.

Thanks for the link to the GBK brake switch, that looks like the perfect solution to allow me to use my own brake levers.

Also, thanks for the pic of the torque arm. Still deciding on which one to purchase. I don't know if I have the proper tools to modify the one from GBK.

Appreciate the help!

 

[d8veh]

I'm just looking at your list of bike components again and I see you mention V-brakes. Get some forks with a disc mount and install a proper hydraulic disc system there. You can keep your cable brake at the back for easy brake switch installation. Don't forget that you'll be going a lot faster with your motor and your bike will be much heavier. Any branded hydraulic brake from Juicy, Avid, Tektro or Shimano will be OK. You can get them from about $50.

 

[jebike]

I have some mechanical disc brakes lying around. I think I'm going to get a rotor and throw one on the front. The mechanical ones I have now aren't to great, which is why I was going to use the V's.

I plan to upgrade to some hydraulic or BB7s as time/money allows. I just order a Surly fork today w disc mounts.

Thanks for your help.