Eboost -kepler friction drive review and testing

[BikeFanatic]

This is a review of Kepler Eboost friction drive electric bike kit , the review also compares his drive to my other ebikes all hub motor kits. This is not really a build thread as I am not building anything, this is directed at the ES crowd but mostly toward people who know nothing about Ebikes or RC drives and are interested in getting started with a simple kit. ( So included is some very basic information).

I have been into electric bikes for a few years and have Hub motor bikes put together from kits. I was very excited when I heard of this kit as I feel this could help more people get into EBikes, as Hub motors are so heavy. I think this drive could open up the ebike market to apartment dwellers and people who live in the city and do not have alot of room for bikes.
For me, I wanted the Kepler drive to build an ebike for my sister who lives in NYC, in a 3rd floor apt, I wanted light and small.
Keplers Eboost seemed like it would fit the bill.

I ordered and received my Eboost friction drive in abourt two weeks time from Australia to USA.
I paid about 380 FOR PLAIN Aluminum ( non anodyzed) drive and throttle interface.

For those who do not know Kepler makes the drive but you have to buy a motor seperately, an ESC (a type of controller for RC motors, and a Magura throttle as well as a throttle interface ( that you either have to make from a Potentiometer, or maybe you are lucky and Kepler will make one for you)

I told Kepler I have never forayed into the RC world and didnt know much about it, so he reccommended the following necessary parts. He also sold me a throttle interface so I didnt have to modify a potentiometer ( more on that later.)
so the laundry list, prices include shippping in USD


Eboost kepler drive and throttle interface $ 381
http://www.eboo.st/

$75
motor turnigy HTX 63-74
motor 55$Model: HXT63-74
Input Voltage : 10~36V (3~8S Li-po)
Kv : 200 rpm/V within 10%
Dimentions : 63mm X 92mm
Shaft diameter : 10mm
Weight : 914g

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3890


$102
castle creation ice 100- the ESC ( the controller)
http://tinyurl.com/284e5mq


http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9283
gold connectors 2.73
Connector : 4mm Bullet-connector



throttle 43$
http://www.holmeshobbies.com/home.php?cat=20

Battery
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9174

the bike I used is a downtube folder basic model $330.

http://www.downtube.com

 

[BikeFanatic]

Here are a few pics of the set up - There was an instruction PDF manual and Oatnets build thread is very helpful. For rookies it take some time to set it up and test it - but a saturday afternoon covered that.





initial impressions so far
1.The parts went together well and appear very profesionally built.
2.The controller is small and hidden in the drive and I found this controller mounts much easier and more stealth than any other hub motor kit.
3. This thing is so light! all togeter Eboost drive motor and esc weight is 4.6 LBS ( compared to my 9C hub motor that weighs 15.9 pounds including controller and rim.

I rode the bike around my neighborhood and was impressed. The castle creation controller works well with the throttle no stalling or any synch issues.

Top spead was 22.9 MPH on the flats with 5 series Lipo, thats an 18-20 volt battery.

I will discuss more in the testing section later, but I came accross a problem initially.

I had ordered the drive to fit my seatpost as there are many seatpost sizes. I received two aluminum shimsfrom Kepler to fit my seatpost so the drive can attach, much like a seatpost mounted rear rack on a mountain bike. However one shim is too small and the other too big. I believe my seatpost is only a tad off but I shimmmed it up good, I thought, with some rubber, still when driving around after a few minutes the drive would come loose an hit the wheel. DARN.

One solution /idea is to use the too big shim and just place a locking collar underneath to prevent slippage. or even a hose clamp.


another Idea is to cut the smaller aluminum collar I got in half with a hacksaw so it will fit as two halves

Or i can buy another shim from pricepoint I have a link from somewhere but this will delay testing. Or I could try the drive on another bike.

***Note to new folks*****this fitament problem is not unusual at all in kits, because bikes are so different in sizes and everything is not standard so there are always adjustments to be made with any kit. When a kit is manufactured it can not be made to fit ALL bikes. I have similar issues with the Hub notor kits, once I had to file the dropouts so the motor would fit or buy special washers, once I had to change shifters, so no kit is PLUG AND PLAY for all bikes.

 

[BikeFanatic]

Here are my options, Iam going to try First to re shim then maybe the hose clamp underneath to support it.
Unless someone has another Idea :?

 

[buzzfirst]

Hello, If the bigger shim is not too too large you could saw a slot in it like the small one shows and it would close up when you tightened the clamp.

 

[AussieJester]

Thankyou ianmcnally2 for taking the time to give an unbiased review outlining the good points of this kit and also possible problem areas a new buyer might encounter, this will be valuable info for future buyers. I realize this kit wont be fore everyone but there are alot of road riders that would love the simplicity and light weight this setup offers IMHO.

As you mention, the fitment problems will be an ongoing thing its simply not realistic to expect the kit to fit EVERY kind of bicycle theres just too many differences. Cutting the larger shim so it closes around the seat tube would be the course of action i would recommend. The clamping pressure will soon 'form' the shim to the shape of the seat tube i believe, you could also perhaps spread some loctite on the inside of the shim prior to fitment.

Well done to Kepler on a great kit at an affordable price.

KiM

 

[maydaverave]

Could try beer can shims if its not to loose. Couple layers of thin aluminum.

 

[BikeFanatic]

Thank you for the replies, I going to work on this tonight, so I can test again in the AM, or maybe I can ride tomorrow afternoon and provide some real life numbers.

 

[AussieJester]

Couple layers of thin aluminum.

Aluminium soft drink/beer cans are an excellent source of thin sheet aluminium from which to make shims, can cut them with scissors too
so no 'special tools' needed....look forward to your next update post ride ianmcnally2


KiM

 

[BikeFanatic]

**FIXED THE PROBLEM***
So the fitting issue was not so much the shim job but the actual seatpost clamp on the Kepler drive. I like the idea of beer cans shims they are roundish and cut up could work very well for this project, sharp though be careful. If you are buying this kit
consider buying a six pack as well or back up. :lol:

Back to the problem
The seatpost I have is very small as this is a small bike. I found that when mounting the Eboost, the adjustable clamp didn't tighten enough around the bike seatpost so that there was lateral movement. I could literally twist the drive side to side with very little effort . Now I believe it was the lateral motion that was causing the problem. Originally I thought when I hit a bump the drive slipped downward, but it was a sideways slipping. So under the seatpost clamp I added some rubber,and now I can tighten the thing down and all seems well, No movement. So rule one is get everything tight and try to twist everything to test tightness before taking off.
here is the bike and the drive - notice i am loosing the grip tape prematurely- maybe because i had fit problems. Someone recommended skateboard deck tape.

 

[BikeFanatic]

So now some data on the bike ride. I start with 5 series LIPO 18-20 volt battery. Here is the bike with the battery installed. I started with a 5 series Lipo 5amp hour (15C). Me, the bike. motor and battery weigh in at about 165 lbs. I know I should use two batteries in parallel but this was just around my area.
the battery



Kepler gave me two Jumpers, one is 70% throttle limiter and the second one is 100 percent, this works with his throttle interface
and as far as I can tell this is used to limit current so you dont use all the power your battery can deliver. I am testing to see the difference see below.

So running on 5 series I went up to 22.9 MPH on flat ground using the 100 % Jumper, I can pedal the folder only up to 12-14 MPH
with the stock gearing then Zoom up to 22 wow - The Eboost makes the folder rock, I do not feel any resistance to pedaling so I can pedal at any point say if i run out of battery or If I am riding in a crowded area or on bike paths where electrics are not allowed. There is no noise when not using the throttle. I think this no resistance is a big PLUS because with the 9C hub motor the resistance of the magnets make it difficult to pedal with a dead battery. I think this drive would be a great assist on a road bike to help on the hills and when you need to go fast. I can see myself pedaling on the flats getting my exercise then rely on the Boost for hills and merging in traffic. Initial impression; I love this thing, did I say that already?

one CON is the stealth factor-- this thing hangs off the back and is obvious to others when they are close by like at a stop light. I had a few inquiries at various stop points. Just because this bike is a folder I get a little extra attention, but the drive sticks out and people ask, is that a generator? So far though people only notice the thing when I am at a bike rack or at a red light with other bikers. Actually only other bike riders noticed so I think maybe other bikers naturally check out other peoples bikes. I know I do.

I do not mind the sound when riding, I think it sounds louder in the videos than when riding. Will upload a video now and a few more later. I notice a high pitch whine when accelerating. I cut the throttle when passing PEDS as I ride alot on bike trails where Ebikes may be illegal.
With the 9C Hub motor, that thing is Very quiet, I can ride by peds and other bikers and they do not even notice it is electric.

NOW for a SPIN

Back to the Eboost- I rode in the cemetary in my neighborhood and got some numbers. This data is not averaged over time but just one day testing.
Using the 70 percent throttle jumper that Kepler sent me-- I got 57 amps Peak and 1000 Watts peak, max speed 22.2 MPH

Using the 100 percent throttle jumper that Kepler sent me-- I got 70 amps Peak and 1200 Watts peak, Max speed 22.9 MPH

15 Watts per mile initially - similar to the efficiency I get with the 9c Hub
but more testing is needed this is one days test.
This set up can pull some amps, In order to get ten miles I think I will need two 5series lipo in pararell, That would put battery cost
at about 150-160$ including chargers. ten no pedal miles.

I did 4 miles around town. here is some data ( don't fall asleep on me). Everything ran Very smooth no issues. I hit low voltage cutoff a couple of times near the end while on hills. I was running one 5series lipo 5 amp hour so I expected some sag, the Voltage minimum was 16.5 V and the controller cut off but I just throttled again pulling less amps and I continued on my way without having to unplug or reset anything. I am pretty sure the cut out was low voltage battery protection from the controller, the Ice gave me a
signal after that of two beeps every six seconds. I don't speak Castle creation ICE yet, but I think it was Low voltage as I heard this controller auto senses LIPO and sets the Low voltage cutoff accordingly.

data- If your still with me

4 miles
max speed 20 MPH
AMP HRS 3.25
Watt hours 58.4
V MIN 16.5
watts mile -15
watts peak 1,268
amps peak 58.4
moving avg 12.5 MPH

 

[BikeFanatic]

I have a few short videos this one is mostly so people can hear the sound, I never uploaded a video so hope it works. i have a few other videos but i need to trim them.
[youtube]pCQT4ruRspA[/youtube]

 

[spinningmagnets]

I'm very glad to see Kepler drives getting onto the streets. If anyone has an odd-diameter seat-post, there is a company that makes just about every possible combination of adapter shim for handlebars and seat-posts for $7 each. They are called "Problemsolvers".

If enough customers ask for an unususal adapter that is NOT made anywhere, they will make one up from scratch for beta testing and customer polling to see if there is a market for it. They specialize in the odd products that are not carried in most catalogues.

(Here's Oatnets Kepler-drive build thread that was mentioned earlier in this thread: http://endless-sphere.com/forums/viewtopic.php?f=28&t=21309 )

http://problemsolversbike.com/index.php/products/seatpost_shims
http://problemsolversbike.com/index.php/products

 

[D-Man]

4 miles
max speed 20 MPH
AMP HRS 3.25
Watt hours 58.4
V MIN 16.5
watts mile -15
watts peak 1,268
amps peak 58.4
moving avg 12.5 MPH

Is there any way to get economy out of one of these rc motor setups? They all seem like amp eaters.

 

[amberwolf]

This one seems pretty economical to me, given the speeds/terrain/etc.:
58.4Wh / 4 miles = 14.6Wh/mile.

 

[TPA]

Is there any way to get economy out of one of these rc motor setups? They all seem like amp eaters.

They are indeed amp eaters, simply because the voltage is half of what you see most people use.

He is only running something like 20V which requires 50A just to break 1000W.

If you were to run, say 12s instead of say 6s it would require the type of amps you are accustom to seeing.

A watt is a watt, doesn't matter if it happens at 1A or 100A

 

[BikeFanatic]

TPA is corect about the watt thing. The watts per mile seems to be equivalent to what I am getting on my clyte and 9C hub motors. 15-18 watts a mile with some pedal and many starts and stops. I also travel at slower speeds 15-20 MPH.

there is more testing coming and videos may take another week of testing before I continue the review.
I'll try to make short but interesting vids.

 

[BikeFanatic]

Its been about two weekd testing now and I am loving this thing. i have some more short videos and a little more to add.
he bike has worked well with a couple snags that I have worked out with some advice from the ES crowd.
One is using shims to keep the drive firmly attached to the seat post. Cardboard worked OK but only holds or a few rides then fails but I need some aluminum to try so I will be using a coke or beer can. There is also the problem solver seatpost shims that would work nicely that was my plan but havent gotten around to ordering yet currently working with cardboard shim.

http://problemsolversbike.com/index.php/products/seatpost_shims


Also the 3M outdoor no slip stair tread to help the friction drive adhere to tire wore out quickly, one solution I am trying is the carpet tape and sandpaper that was suggested. This tape is very sticky. It is also cheap so for 4$ I got the tape and the sandpaper8 pack was 2.50= $ 7.50 and this should last forever as every sandpaper sheet gets cut up in four pieces you need 8 inches to go around the motor,so even if i have to change sandpaper every 2 weeks it is economical.The stair tread stuff is 2$ a foot and rubs off in less than a week .

I love the bike, the drive is so light and the bike I can lift it out of the cellar any time for a quick run to the store and I have used a single less than 2 pound Lipo for these short trips of 3 miles. It amazes me that I can only add a 6-7 pounds to the bike for motor and battery, makes this setup very versatile.

Another plus is security wise-- I have taken the bike to some area bars and I lock the bike outside and just pull off the seat post with the drive on it and bring it in with me. Then I am only out a $300 bike if it is stolen.

another plus is I can try this on another bike if I like, say my road bike.

Except or the roller material problem which we are working on here I have to say this drive is working flawlwessly, it is causing quite the stir in my neighborhood where everyone wants to try it. I'm calling it the F drive and now I wonder if I can really give this to my sister as planned. I might have to get another one for me. Here is Lisa in my neigborhod park ( the cemetary)
The drive starts of with a little whistle then is relatively quiet but not as quiet as the 9C hub motor. ( Sorry for the wind noise maybe turn yor volume down first).

 

[BikeFanatic]

here is the wear after a few uses with the 3M stair tread stuff I found at the hardware store.
the other pic on the right is some 3M outdoor stair tread, do not waste your money - here is the carpet tape and it is very sticky.

 

[BikeFanatic]

 

[BikeFanatic]

I got these bags on ebay to nount two 5 series, they barely fit in the bags i am looking at the bigger ones - these are all over ebay I got them from a guy in texas. they are a tad small 5.5inch x Width 4 x Thickness 1.7 (inches)

http://tinyurl.com/2frjlne

 

[BikeFanatic]

VIDEOS
[youtube]lI2OM0uBsg0[/youtube]

 

[BikeFanatic]

LisaRides.mov
[youtube]4XjBaO813JQ[/youtube]

 

[BikeFanatic]

[youtube]LL1xk2doyy0[/youtube]

 

[amberwolf]

Some how I expected it to be noisier; even accounting for teh wind noise overwhelming the mic, it's quiet enough.

You might see about putting some foam over that mic, though.

 

[melinda032]

COOL

I am interested in your set up I really like the lightness of the folding bicycle too. Which types of battery pack do you
recommend? It needs to be a strong battery you say, Does that mean only Lipo (Lithium poly ?) Sorry i am new.