going electric, converting one of my bikes

Hi. I've been reading a bit/lot here lately, but I can't find answers to all my questions.

My energy is running low atm, so I need a bike with it's own energy to get me around. I've go 3 bikes and wanna convert one of them rather than buying another, don't care which one is converted.

Trek Superfly 100 carbon FS 29er with a wide BB and press fit bearings.
Salsa road bike 10sp carbon fork with BSA BB, haven't measured yet but I hope it's 68mm
Giant XTC 26 hardtail 10sp with an 86.5mm BB

In Norway hand throttle is not legal and 250w/25kmh max. I just wanna get around and have no problems with these rules, not looking for a high speed/pwr setup. I think the PAS is the key to a good setup. I'd really like a torque sensored setup along with a high/medium/low assist switch. I've read about Bafang and torque sensors, but I'm not able to determine if the bb01/2 comes with torque sensor now. How about the CST rear hub?

If I go mid engine I will have to convert my road bike.
-I'd rather use the existing brakes on the road bike, do I really need brake sensors if I got torque sensor?
-Bafang bb01 is not reccommended with 9/10sp drive train. Is there a torque sensored mid engine that will work with 10sp?

Going the DIY route is gonna take some time, and I'd wanna get on my bike sooner rather than later. I've been looking into Klyfly and Copenhagen Wheel, but that will take even more time before they're ready to ship. Any other options? If I get frustrated enough I might just get the very expensive Rubbee :/

Those are some pretty nice bikes. Composite bikes are less appropriate for ebike conversion, but can be used on a low power ebike.

If you want to get riding cheaply and quickly, hubmotors are probably your best option instead of a mid-drive. There are a number of kits like the Bafang motors and Q100 motors that sound like they'd be perfect for you, low to medium power and PAS compatible (though I personally hate PAS and only use hand throttles even though they are illegal here too).

A hubmotor will also be easier for you to install yourself.

A Q100 kit, with a 36V lithium battery could be something in the neighborhood of $500 shipped from BMSbattery.com

If you still want to go with a mid-drive, the bbso1 is more appropriate for you. The second version is meant for the American market and is higher powered - not something you're looking for.

How hilly is it there? If it's pretty flat, a standard $3 PAS sensor is all you need. If there are big hills, the torque sensor will be better (but much more expensive).

You don't HAVE to have e-brake levers, it's just something that some people add. It cuts out the throttle when you pull them so you don't accidentally give gas while braking at the same time. They can also be used to turn off cruise control if you get a kit with cruise.

Thanks, the Salsa and Giant XTC are both alu, one with a carbon fork, the other with a Reba suspension. I guess the fork situation means no front hub engine.

The reason I'm looking for a torque sensor pas is that I want a system that gives me some assist if I pedal lightly and max assist if I pedal harder, so everything is automatic and I don't need to bother with a throttle. When braking, I don't pedal of course, so there shouldn't be any engine force to resist? A crank sensor based pas will not cut engine power right away and I will have to resist the engine force when I start braking? At least that's how I think it will work

My area is a bit hilly, mostly up and down, no Alps style climbs

The crank based PAS sensor is simply a cadence sensor, so the faster you pedal, the faster the motor spins. This is ok for flat ground, since the faster you pedal the faster you are going, generally. The problem is this type of sensor is less good on hills, because even though you are pedaling slower, you still want the motor working hard. If you just have some medium hills then it will probably be alright.

You won't have to worry about braking with it. as soon as your stop pedaling (or sometimes a second or so afterwards) the motor should stop as well. That's how a PAS is designed to work, as long as you don't have a cruise control feature.

There are no mid drive motors with a good torque sensor. But there is a great torque sensor for a hub motor. It's not cheap, though. The THUN BB senses how much torque you are applying to the pedal, and can adjust the motor output to compensate. You would need to combine it with a Cycle Analyst version 3 to get the most out of it, but it would then be compatible with just about any kit. With the CA, the assist level is fully setable Its a little more involved than just a kit, but it is the best system available. Almost everything else trys to match your cadence, not your effort.(There are a few versions of the CA, depending on what motor you get and where you get the controller)

CST drives may be a problem. There are only a couple motors that can take a CST, and none can take 10 speeds. the motor and gearing in the hub is just too thick for that. Bafang makes a 250, 350, and 500w version of the CST. Andana Cute makes a version of the Q100, and there was a 3rd motor available. You may have to convert the drivetrain to a lower gear count. But with motor assist, you'll find you use only a couple gears ever.

Brake cutoff switches aren't needed. With a geared hub, they serve no real purpose, as there is no regen or E-braking possible on a geared hub. If the unthinkable and nearly imposable should happen, and a total programing failure happens in the controller, causing it to take off at full speed (and you're more likely to win the lottery) then simply applying a few grams more pressure on the brakes will stall the motor out and allow you to simply turn it off after stopping safely.


Sadly, the Copenhagen wheel has been a project Coming Soon! for about 5 years now. Glaciers will be in your town soon, too. I think they are working on the same definition of "Soon". They certainly are moving about as fast.

Okay, no point waiting for Copenhagen Wheel then, Flykly might be better delivery wise? But then I would have to go single speed, or keep the drive train and get 2 gears from the crank shifter

Bafang 250w cst
http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2013-3C-C6H5.4FUVV
and GBK 100 cst
http://www.greenbikekit.com/100cst-cassette-freewheel-e-bike-kit-36v-250w.html
both accept 9 speed. Usually you can fit a 10s cassette on a 9s hub, but I've got a 9s derailleur and shifter in the shed so 9s is okay. It's a bit tempting spending 100-something-$ for the GBK 100 cst, just to try...

But I really want a good product that I'll be satisfied with, and I believe torque sensor is essential. ebikes.ca sell a kit with the torque sensor bits, but $1100+ w/o battery is a bit too steep. BionX got kits including battery starting at $1195, but it's 26V, worth considering? http://electricvehiclesnw.com/index.php/other-products/kits/bionx-kit-detail
BionX is actually sold localy, unless prices are insane that could be an option. Warranty through a local dealer and quick delivery is worth a bit.

Every now and then I consider the Rubbee, is it pointless?

The Bionx are proprietary systems. You have to like what they give you, because there is no changing it. That's fine for some. but if your needs are different than what they offer, you're out of luck.

Ebikes.ca's full kit is a 500 watt kit. not legal for you, although it would be fun. The smaller motor they offer is front only, and you have carbon forks, so not an option. As for the price, 1100 is what that kit is worth. Ezee motors are the highest quality out there, and the THUN and CA are >$400 alone. The Ezee is also not CST, so the full kit isn't what you need.

As for the Rubbee, it's functional, and probably the prettiest roller drive around. But it's a roller drive. Horse-and-buggy technology in the world of high tech ebikes.
If you really are interested in roller drives, a Kepler drive at least brings modern tech and design to this ancient idea.

As for the Klyfly, they also have been in pre-order for a while. and there isn't much battery that can be stuffed into a tiny motor like their current design shows. range would be very short compared to anything else.

Drunkskunk said:

(and you're more likely to win the lottery)

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I'd like to take that bet!

knut7 said:

Flykly might be better delivery wise?

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No need to go for the copenhagen wheel or the flykly (is there a consensus on which one ripped off the other?) since they're both overpriced, overrated parts. Spend a quarter of the money and get better performance. Put some of the money you saved into your battery (the single most important purchase when building an ebike). Consider the Q100 @36V with a bottle battery or two (if you don't need long range) or a shrink tube battery in a triangle frame bag (my favorite) if you want more range. Use a 6 speed freewheel and set your derailleur to align with the top three or four gears, you'll probably only use the top one or two anyways.

The rubbee is a novelty. It'll also destroy your tires over time.

Bionx is super expensive for what you get.

ebikes.ca is the love child of ebikes and all things great. Their prices are higher but they'll always make you happy.

BMSbattery.com is one of the cheapest places to get motors like that 100CST you found on greenbikekit.com They are basically the same site. I still don't know what the story is there/why the two sites are like really close brothers. Maybe a BMSbattery worker defected, idk. Anyone know the story?

Just my advice. but there are a lot other people giving good advice here. Theirs is probably better than mine.

Thx for your replies btw

So I guess Cph, Kly, Rub and the likes are out. I picture myself being happy with a BionX kit, but perhaps not the 250w 26V one, and then it gets really expensive! ebikes.ca isn't really any cheaper it seems.

Why would I pick the Q100/36V over the 100CST/36V? I'm tempted by the 9 speed CST. Picking up a cheap kit like one of those and spending a fair bit more on a battery could definitely be the way to go. Then I would have to forget about the torque PAS or I might as well go BionX.

I've read some seriously bad BMSbattery reviews on this forum, whereas greenbikekit seems to have a better reputation. But this info might be old and outdated?

Here's one that claims 10s compatibility
http://em3ev.com/store/index.php?route=product/product&path=45&product_id=179
26" disc brake rim, 10s hub, thumb throttle, hwbs sensor, black spokes, disc spacer and torque arm makes it $849. Without a display... dunno if I need that.

Yeah, I know, 500w. But at least it's limited to 25kph

knut7 said:

Why would I pick the Q100/36V over the 100CST/36V? I'm tempted by the 9 speed CST.

I've read some seriously bad BMSbattery reviews on this forum, whereas greenbikekit seems to have a better reputation. But this info might be old and outdated?

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going without the CST will be cheaper. And I highly doubt you'll make full use of all 9 gears. It sounds nice to keep it close to what you had on the bike, but really most people never shift out of the highest gear because that's the most comfortable one to use on an ebike.

I've read some really bad review of bmsbattery and i've also read some great ones. For me they've been great - the couple times they got something wrong they either refunded me or sent me new parts. they have been great with contact for me. one of the guys that work there even helped me locate a folding 16" bike in a market near his house (hard to find here in Israel). I think it's sort of a crap shoot. maybe you'll get great service, maybe you won't. I've bought a bunch of stuff and worked up a rapport with them, so that's probably helped me.

If you are worried about legality, most kits are unmarked, i.e. there's nothing saying it's a 500W kit on the parts. Sometimes there's a sticker on the controller or motor that you can remove. Even better is to just print up a 250W sticker at home and stick it on your motor. I've got one on a 1500W motor :lol:

I probably won't be needing all the gears when there's still juice left in the battery But the main reason I'm looking at a CST engine is that I won't have to change any parts in the drivetrain.

If I buy a Q100 36V kit such as this one
http://www.bmsbattery.com/ebike-kits/615-250w350w-q-85100sx-motor-e-bike-kit.html
I don't know what freewheel I need, and if I need to change rear derailleur and shifter to work with a 6speed freewheel. If I need to change parts, then it will be cheaper to go with the Q100 CST
http://www.bmsbattery.com/ebike-kits/615-250w350w-q-85100sx-motor-e-bike-kit.html
But I've read about reliability issues with the CST.

I've decided to make this as cheap as possible. If someone could please recommend me a 350w or 500w kit to go with a battery like this
http://www.bmsbattery.com/36v/571-bottle-ebike-battery.html

CST or not, depending on what's cheapest/easiest to fit my bike. I will be installing it on my 2012 Giant XTC alu, it's got an 86.5mm pressfit BB if that makes a difference regarding the PAS cadence sensor. I guess I'll be needing a throttle, I'm thinking thumb throttle, but I haven't tested either. Need a disc brake wheel.

knut7 said:

If I buy a Q100 36V kit such as this one
http://www.bmsbattery.com/ebike-kits/615-250w350w-q-85100sx-motor-e-bike-kit.html
I don't know what freewheel I need, and if I need to change rear derailleur and shifter to work with a 6speed freewheel.

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You'll need this 7spd freewheel: http://www.bmsbattery.com/ebike-parts/48-14-28-teeth-shimano-freewheel.html

Works like a charm. I don't think you'll need to change a derailleur or shifter or anything, just adjust them to match nicely with the high end of the gearing.

The nice thing about the bottle batteries is that they are slim and you can actually get a couple since they are so cheap. That way you can just stick one in a backpack or on a rear rack if you know you are going for an extra long ride. They are also nice and easy to bring inside with you to charge when you stop somewhere. And when you take them with you they don't look as much suspicious like a bomb as the heat shrink batteries do. But maybe that's only an issue where I live.

They are only good up to about 500 watts though. 350 watts is kinda their sweet spot.

Okay, so I'm down to these 2 options

GBK100-R 36V 8.8Ah battery with cassette
http://www.greenbikekit.com/electric-bike-kit-1/rear/gbk-100r-36v-rear-driving-kit-bottle-lithium-battery.html
http://www.greenbikekit.com/accessories/ebike-wheel-kit-parts/shimano-freewheel.html

or Q100 36V 10.4Ah battery with cassette
http://www.bmsbattery.com/ebike-kits/577-250w350w-q-85100sx-motor-e-bike-kit.html
http://www.bmsbattery.com/ebike-parts/48-14-28-teeth-shimano-freewheel.html

Any recommendations? Otherwise I'll just pick the one with the best shipping deal, if shipping is the same then I'll pick the Q100 with the 10.4Ah battery. Wanna order today and get started as soon as possible, so I don't need any surprises and extra work when I get the stuff

Thanks for all your help.

They are identical with the exception that the greenbikekit option has the slightly older style bottle battery that lifts up and out instead of the newer style that comes out to the side. The newer style doesn't require you to physically unplug the battery connector every time you take it out, which I think is a major improvement. It also has a usb port to charge your phone and stuff, if you should want something like that.

Other than that they are the same parts. same motor, controller, throttle, etc.

Okay, I'm signing up with bsmbattery to get the shipping cost. The little extra Ah from the battery should come in handy, and USB port is nice provided it doesn't get filled with water when it rains

Thanks again for your help.

no problem.

I prefer BMSbattery myself, but I've worked with them a lot so I'm biased.

And the usb should come with a little plastic dustcover - though who knows how long it will last…

Make sure you come back and update us once you've built your bike. It's always fun to see someone go from the learning stage to the doing stage!

Will do.

$560 incl shipping, order sendt :-o

Started wondering about how to install the cadence sensor (pas). Can a sensor such as this be installed on a bike with press fit BB?

Yea you won't really be messing with your bb at all. You just pull off the crank (one bolt) to slide the components on. You'll likely need a crank puller though. If you don't have one, it's like a $10 or less tool most places. It's one of the few tools I don't mind buying a cheap one of, because you'll probably use it maybe a couple times in your entire life, unless you plan on installing these things on all your neighbor's bikes :wink:

heck, you can probably take your bike down to the local shop and just ask if you can borrow one for a second.

Bike's got an SLX hollowtech ll crank, really easy to disassemble. Problem is there's not much space between the bb housing and the crank.

wow, you weren't kidding, that is tight.

I'm trying to find a similar install on here. This guy has a similar crank but I think his bb allows for more room. any chance to shimmy out the crank a bit? http://endless-sphere.com/forums/viewtopic.php?f=2&t=12109

That guy's got a BSA (possibly ITA) 68 or 73mm BB. The sensor is attached behind the Hollowtech II BB cup, that will not be possible with a press fit BB. I'm thinking I'll have trouble both attaching the sensor ring to the frame and fitting the disc to the crank!?

Tried googling <cadence sensor "press fit"> a few times without finding any info addressing this issue :/

knut7 said:

That guy's got a BSA (possibly ITA) 68 or 73mm BB. The sensor is attached behind the Hollowtech II BB cup, that will not be possible with a press fit BB. I'm thinking I'll have trouble both attaching the sensor ring to the frame and fitting the disc to the crank!?

Tried googling <cadence sensor "press fit"> a few times without finding any info addressing this issue :/

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Worst case scenario I think you may just need to do a custom solution. I'd probably cut the ring off the sensor piece and mount just the sensor on the top of the bottom bracket. JB weld will do it. Hot glue would be a less permanent but still strong solution. Then something similar to mount the magnets to the crank.

It may be that the factory solution doesn't work for you, but I'm sure you can find a nondestructive (to the bike) workaround, if you need to. You'll have to wait to see what your options are when the PAS comes.

I'm a little late, but....
I believe D8veh has fitted a Pas sensor to a Hollowtech BB. Search his posts.
FYI, a DNP 9-speed does fit with the Q100 in 135 mm drop-outs, but I would have gone with the CST myself.
With the Cute on 36V, you will be rowing thru the gears.

What was the motor speed ordered?