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E bike kit lightweight

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Old 07-13-16, 12:57 PM
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tom doughty
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E bike kit lightweight

Hello
I'm about to buy a kit and here asking those of you (all of you) who know far more than I.
My two most important requirements are low weight and an assistance that allows pedal cadence to remain as constant as possible when load increases and the motor assists. I would also need a high proportional level of help from the motor as I'm not strong and my cadence is slow. Speed is not important, but torque is.
Reliability is too and ideally a geared motor as I won't always use the assistance but don't want to drag a motor around in the hub.
So far, i've enquired about Keyde who impress with weight and would offer me rpm of 195rpm. but I've read concerns about their reliability and once I buy the thing and install it, I don't want to do it all again.
The motor would be in the rear wheel, fit with a disc brake and a cassette.
Any thoughts out there?
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Old 07-13-16, 02:52 PM
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If your're set on a rear hub with cassette, pedal-assist and reliability, BionX is by far the best choice IMO. The motor will weigh 8 or so pounds. Lighter weight can be achieved with a Q100C or Q128C motor system (BMS Battery which is a crap shoot). There are also good OEM bikes; read their reviews (electricbikereview).
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Old 07-13-16, 07:09 PM
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Although I have no experience with rear or front hub motors (only mid-drives), I am hub curious.

I was reading up on front hubs and the the BMS Q100H was mentioned by a much more experienced hub motor guy on (something?)sphere (dot) com. The BMS sight stated it has more torque than some of their others. I believe they make it for rear disc too.

This is the "front" disc hub motor I'd like try some day on a suspension fork and being 350W/36V my existing quality battery pack I use for the 350W/36V BaFang mid-drive will power it too.

You might ask the guys over on (something?)sphere for more detailed info.
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Old 07-14-16, 02:58 AM
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tom doughty
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Lightweight

Thanks..I've tried to contact Endless-sphere.com and no answers as yet, but on the case.
Does anyone has knowledge/experience of Keyed motors? they are very light, but I would like to know about reliability.
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Old 07-14-16, 07:41 AM
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My opinion is that unless you are already a hard core road biker, or a dedicated and bruised up mountain biker, weight only matters when you lift the bike up onto a car rack. Do you need to feel your bike leap forward with each stroke on the pedal in top gear. Or are you someone who can feel the extra weight of an eight pound battery strapped to the rear rack while dodging boulders down hill?

Motor and battery will add at least 12 pounds. Probably more around 16 for typical kits. For riding around in streets and paths, that's nothing to a 250-350 watt geared hub motor. If it wasn't, all the Europeans would be wrong, as that power level is all they get for daily riding.

You can either start at the high end or come up from the low end. My first bike had a $200 rear geared motor, and a $300 battery off ebay. Almost as important than the motor is good tires. I put on nice street tires and my bike rolls well, and is easy to pedal with the power off.
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Old 07-14-16, 03:50 PM
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Endless Sphere caters more to the high-power group; however, if you're interested in a Q-100C (4-5 pound motor - the "C" denotes cassette) and Dveh answers, you're in luck. He'll probably recommend a S06-type controller; with a lightweight battery (you can get the latest 36V or 52V, 7 ah which weighs about 3 pounds). Total for the kit would be about 10 pounds.
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Old 07-15-16, 03:41 AM
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tom doughty
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Lightweight

Excellant help 2old....Weight is most important to me because the motor is to be fitted to my hand cycle that I have to lift and carry and I'm not strong. Similarly, the battery, every pound added is an aching joint or muscle. Riding wise, I don't go fast or far but I am interested in reliability and torque. I'll go and check out the Q-100C. Keyde rear hub motor looks really light but there are seemingly problems with reliability.
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Old 07-15-16, 07:29 AM
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Tom, also post on Pedelecs.co.uk since Dveh is in the UK. He's the "world expert" on lightweight motors IMO.
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Old 07-27-16, 02:06 PM
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Here is my light weight bike build on endless sphere:
https://endless-sphere.com/forums/vi...9691&start=100

I have a thread on it here too, although it is probably 3 years old now.

I use a light Q100 and the latest battery technology to build a bike that weighs 29lbs, range 25 miles, speed 25mph. That is about the lightest I have seen (other than some extreme carbon examples).

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Old 07-27-16, 02:07 PM
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Originally Posted by 2old View Post
...with a lightweight battery (you can get the latest 36V or 52V, 7 ah which weighs about 3 pounds)....
You talking about my custom 3lb build from em3ev, or something else you can point us to?
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Old 07-27-16, 03:13 PM
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Chas, Luna Cycle has "3" pound square batteries that are 52V, 6 or 7 a/h.
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Old 07-30-16, 07:20 AM
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Originally Posted by Doc_Wui View Post
... For riding around in streets and paths, that's nothing to a 250-350 watt geared hub motor. If it wasn't, all the Europeans would be wrong, as that power level is all they get for daily riding. ...
That comment says wonders about the Europeans years of experience with E-bikes!

I found that a 350W mid-drive is plenty of power for even an eMTB with proper gearing. Remember the stated watts are nominal and peak watts on a 350W motor is typically around 650W. If you are a PAS rider that likes the "feel of a bicycle", you will find yourself toning down the level of assist power on even a 350W. I prefer to run at level 3 of 5 and even that provides a huge assist. I only max out the assist on the 350W motor when I'm in a real hurry or climbing a steep hill.

One area that I'm not clear on is how much weight increases with the increase in watts of the motor???

I have to agree there is something to the size the Europeans settled on for most of their e-bikes...
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Old 07-30-16, 07:35 AM
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Originally Posted by tom doughty View Post
Thanks..I've tried to contact Endless-sphere.com and no answers as yet, but on the case.

Does anyone has knowledge/experience of Keyed motors? they are very light, but I would like to know about reliability.
I have a hard time finding what I want on that site too. Most people there seem to think more power is better. After using an eMTB for six months, I don't think that way at all.

What conclusion and/or motors did you find that are the lightest out there?

I think it would be interesting to place a super light weight front hub motor in the triangle of a MTB frame, run a right chain ring crank on both sides on the BB, use a 6-hole disc brake mount sprocket to attach the front hub motor to the left side of the crank via a chain and set it up for PAS or just a boost throttle to be used on climbing steep hills only (onboard chairlift). The crazy thoughts that go through my mind...

Check out this awesome light weight carbon hardtail MTB prototype by Focus:



If that link doesn't work (showing a red "X" in a box?), search on Focus Project-Y.

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Old 07-30-16, 11:32 AM
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Tom, did you settle on anything? Forgot about the lightweight battery that Chas 58 got from em3ev which IMO is even a better option than Luna Cycles. Also, there's a Q75 motor that weighs about four pounds that is low power, but may be adequate for your needs.
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Old 08-01-16, 10:09 AM
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tom doughty
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Lightweight

oh yes...not bought it yet but the add E-bike. so light and user friendly for me...250watt will be enough too. https://electricbikereview.com/add-e/250w-kit/ and ADD-E - Add-E Official Online Shop
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Old 08-01-16, 12:11 PM
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Good luck; let us know how it turns out.
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Old 08-01-16, 06:51 PM
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Originally Posted by tom doughty View Post
oh yes...not bought it yet but the add E-bike. so light and user friendly for me...250watt will be enough too. https://electricbikereview.com/add-e/250w-kit/ and ADD-E - Add-E Official Online Shop
That's a neat little unit! The simplicity is great. Surprised they can fit a 600W/22.2V motor into that little package, but I guess they have. They state their battery is 22.2V/7.2Ah and "The 160 Wh battery offers enough electric energy to run more than 2 hours in full support mode." That must be computed based on the 250W version, because at 600W I'd think it "might" be good for ~8 miles.

I like the concept. Definitely let us know how this unit works out. I'd kill to get 2 hours at full power on ANY 600W E-Bike!

Wonder if they have managed to put one on a rear suspension bike? It'd be nice to have a hand pushing at your back on off-road climbs before the big descents...

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Old 08-02-16, 12:00 PM
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Originally Posted by NoPhart View Post
That's a neat little unit! The simplicity is great. Surprised they can fit a 600W/22.2V motor into that little package.......
Court wasn't too impressed with the 600-watt claim and its lack of performance in his review video. Negatives I've read say it is excessively noisy, and there are concerns about it being down in the road-crud zone. Too bad because it is a very stealthy little setup.

Although not pedelec and requiring some hands-on, Ian's simple drive might be a better unit.
Friction drive build for bikes
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Old 08-02-16, 12:34 PM
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While light weight, that review really turned me off on friction drives. Not much power, and very noisy, and 22volts isn't going to give 600 watts very easily. you would need close to 30 amps to do that. Hmmm...

if you don't want a mid drive, the Q100 is your best bet. It is light (2.2kg?) and reliable. you aren't going to do better in a light hub motor.

Something like this
36V 250W Rear driving electric bike kits including 36V10H li-ion frog battery and charger-Greenbikekit.com online store for electric bicycle components-GreenBikeKit.com

$289 plus a couple hundred dollars for shipping.

(if you really like light friction drive designs, this was an interesting idea for short rides:
http://www.fastcoexist.com/3062226/m...-clever-gadget
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Old 08-02-16, 12:34 PM
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Also take a look at the Rubbee; haven't seen what they're up to for a while though.
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Old 08-03-16, 08:38 AM
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Originally Posted by slomoshun View Post
Court wasn't too impressed with the 600-watt claim and its lack of performance in his review video. Negatives I've read say it is excessively noisy, and there are concerns about it being down in the road-crud zone. Too bad because it is a very stealthy little setup.

Although not pedelec and requiring some hands-on, Ian's simple drive might be a better unit.
Friction drive build for bikes
Yeah, I was a little confused about comments relating to it being waterproof and watching the rider cross a stream. The close up photos show big open holes in the sides and you can see the windings of the electric motor. Waterproof? I think not! But I could be wrong...
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Old 08-03-16, 11:52 AM
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Originally Posted by NoPhart View Post
Yeah, I was a little confused about comments relating to it being waterproof and watching the rider cross a stream. The close up photos show big open holes in the sides and you can see the windings of the electric motor. Waterproof? I think not! But I could be wrong...
The motor is vented and probably has sealed bearings. Water will spin out and/or evaporate, but the abrasives left behind might be a problem over time. Also, the sandpaper covered drum is.... sandpaper. Adding road grit to that surface is going to expedite tire wear.

From my perspective, if you are going to lug around the extra weight of an e-power system, it should have enough energy to be useful on hills. I'm not sure the Add-E would create joy. It isn稚 likely that the OP is going to get the ideal "low weight assistance that allows pedal cadence to remain as constant as possible... a high proportional level of help from the motor in the same package. Fwiw, my last e-bike had a 250-watt geared hub and it was okay on level ground but dismal when climbing. Whatever the OP chooses, IMO is should be at least 350 watt.
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Old 08-03-16, 02:03 PM
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Kepler has made some interesting friction drive bikes, and I think he may have gotten around to selling his units.

Either way, his builds are interesting reading for people interested in the technicalities of building a friction drive

https://endless-sphere.com/forums/vi...0048e25f9e6de9

check out the video of the final product in the first post

He is using 7S3P, which is what, 25 volts...

Like my bikes, I don't need a lot of power when I have a good base bike to build off of and strong legs to augment the power delivery. ;-)
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