Cowardlyducks - E-BikeE builds

[Cowardlyduck]

Hi all,

***Edit***
The plans changed significantly on this build, so skip down to here for the Bike-E build I ultimately ended up doing.
***Edit/end***

So after several years of owning, and loving, using my Stealth Fighter as a commuter, I've decided to get sensible and build up a more appropriate bike specifically for the purpose of commuting to/from work each day.
I'm not tossing the Stealth of course, just relegating it to weekend usage, and the occasional commuting via an off-road route.
The new bike will need to be reliable, and cheap to build, since I'm pouring most of my time and money into upgrading the Fighter continually. I want to be able to use Regen, so a DD hub motor is the preference.

I've already got batteries.

These were in my Fighter, but they've started to puff a little, so I'm not comfortable bashing them around off-road any longer. They should make for a nice commuter pack where they won't need to deliver anywhere near the amps my Fighter was drawing.

I've also already got a controller curtsey ready to go.

I've got two bikes to choose from for the conversion. Both were given to me for free from a friend who did many many miles on them over the years. He even rode the Mountain bike from Sydney to Canberra (300km) in one day back in the 90's!

The first option for the conversion (and my preference at this stage) is the road bike.

The second option is the mountain bike.

Both bikes have 135mm rear drop out's. The road bike has 700c wheels and the mountain bike 26".
The road bike rides a lot better and more comfortably on the road (and even light off-road), but it is heavy for what it is. It's weight mainly comes from it's tubular steel frame, which I guess is good for e-bike building since it should also mean it's stronger.

The mountain bike has a strange feel to it due to the extended head stem and geometry. Once you get used to it, it is quite a capable off-road and I've ridden it on some pretty gnarly rough stuff successfully. It's lack of suspension simply means a different riding style must be used. After decades of only riding mountain bikes with suspension, I'd forgotten how responsive a mountain bike with no suspension can feel off-road. You can really flick it around even though it's not the lightest thing in the world(still lighter than the road bike though).
Both bikes are also rim braked, which I will not be changing.

To me, either bike would make a good commuter conversion, however there are drawbacks to each.
The road bike's main disadvantage is the fact that it has 700c wheels. The increased strain on the motor and controller is a disadvantage, but one I'm happy to live with. The main problem is, if anything significant breaks on the bike, it won't be worth fixing and instead I will get another used bike to move the kit over to. In that case I would prefer to be able to buy a used mountain bike, but the motor in a 700c wheel build would not work with that. I've also got some thicker tires to use on the road bike, that should make the ride more comfortable.

The mountain bike has fatter tires for comfort, and being 26", if anything significant breaks it's very easy to buy a cheap used mountain bike to move the kit over to. The only issue with it is the bike is not as good quality as the road bike and the ride is a little strange. The brakes, grips, gears, cranks, and bottom bracket are also much more worn, and lower quality compared to the road bike.

All that's left to buy for the conversion is the motor/wheel and a bag for the batteries. In either case I will be getting a triangle frame bag.

http://em3ev.com/store/index.php?route=product/product&path=43&product_id=125

And for the motor, I will most likely go with the 500W DD hub from Paul @ em3ev.

http://em3ev.com/store/index.php?route=product/product&path=36&product_id=112

The motor wind is slightly higher than I would like at 268rpm loaded (36V), but it still seems like a workable option for 72V LiPo (am I wrong?). I could also potentially change the battery setup from 18S to 12S if it's too fast or inefficient.

Anyway, what do others think about which bike I should use for the conversion? Is there another option I haven't considered with these bikes?

Cheers

 

[Kepler]

Good one CD. Should be a nice commuter setup. 268rpm might be a bit quick on 18S. I would say up around the 65kph mark. I doubt that motor and controller would like that for too long. 12S will probably be a better match and will give you around the 40kph mark. The 700C wheel will be the go on 12S to get a bit more speed. If you want to stick with 18S, the smaller wheeled bike will give it more chance.

Anyway, should be a good project.

 

[TheBeastie]

Hi all,

So after several years of owning, and loving, using my Stealth Fighter as a commuter, I've decided to get sensible and build up a more appropriate bike specifically for the purpose of commuting to/from work each day.
I'm not tossing the Stealth of course, just relegating it to weekend usage, and the occasional commuting via an off-road route.

So after riding for several years of riding a bike that looks like a dirt motorbike on the road did you ever get the attention of the police? Pretty amazingly if you didn't I would of thought. 72v of lipo on a 9c should push you well above 50km/h wouldn't it, but a 6fet controller sounds like low amps, would be interesting to see what performance you get.

 

[Cowardlyduck]

Good one CD. Should be a nice commuter setup. 268rpm might be a bit quick on 18S. I would say up around the 65kph mark. I doubt that motor and controller would like that for too long. 12S will probably be a better match and will give you around the 40kph mark. The 700C wheel will be the go on 12S to get a bit more speed. If you want to stick with 18S, the smaller wheeled bike will give it more chance.

Anyway, should be a good project.

Thanks! I value your input John.

65kph is probably a bit too fast for me anyway.
I already have an 18S harness built (again, curtsey of Jay), and would rather not have to disassemble it unless I have to. Alternatively, since the harness is already divided for parallel then series connection, I could just use 2 of the 4p harnesses together with 8 of these.

I was already using one set of these (i.e. 3; one on each parallel group) in order to run 18S 5P previously since my harness is only made for 4p. Never saw any issues then, and that was with my Fighter pulling up to 90A bursts.
At such low currents on the commuter (by comparison) I don't see these harnesses being a problem.

So after riding for several years of riding a bike that looks like a dirt motorbike on the road did you ever get the attention of the police? Pretty amazingly if you didn't I would of thought.

It's not about what it looks like so much as how you ride it. I always slow down around pedestrians, and don't go much above 45kmh on busy sections of bike path. I'm also always pedalling which helps. In fact, a few months ago, I came up to an intersection via a cycle path where the lights were blacked out. A couple of cops managing the traffic waved me through without a second glance. I was a bit worried, mainly cause I was wearing a full face helmet and ski goggles, but they didn't even seem to notice.
You are partially right though, it's pretty amazing I've never had any negative encounters with the cops, or collisions with other cyclists/pedestrians. I have had a number of less than nice comments as I've sailed by, and one lady even stopped me to tell me she had seen me before and that I was going too fast through a local park. I apologised, and do actually take it a lot slower through that park now.

Cheers

 

[Allex]

Interesting thread. I actually want to do something similar to my wife's bike.
I have four bricks of 37V 5Ah nanos and Lyen 9FET. I want it to be a 37V setup with 26" wheels
As it still needs to be a bike I want to be able to use it without the batterys and look stealthy. So it needs to be pretty light and freewheel easy. So I was thinking about a MAC motor. It is lighter, smaller and maybe more torque in it? Regen is giving so little anyway so that is not important. I am just a bit worried about the Noise, will it be much noisier than Pauls DD? And if I use the DD it will probably be to slow on 37V?

 

[DAND214]

MACs aren't that noisey. If I ride next to my friends DD I hear it and he hears mine. Alone I hear the gears without a roblem Only time they are noisey is under hard acceleration.

10s LiPo isn't bad on a 8t not how on a 10t.

I have gone all geared since having 6 DDs and now I have 6 geared with 2 Dds hanging and 2 geared also, wheels only. Love the low end torque and the lack of wieght, and drag when not powered.

Dan

 

[TheBeastie]

I have gone all geared since having 6 DDs and now I have 6 geared with 2 Dds hanging and 2 geared also, wheels only. Love the low end torque and the lack of wieght, and drag when not powered.

Dan

Cool! I have always wanted to hear the opinion of someone whos heavily had DD and geared.
I have been geared from the get go, I mainly felt it would kind of help force me to appreciate take off torque and not tempt me down the road of DD speed and therefore higher chance of horrific speed based crash.

 

[Cowardlyduck]

The main draw card for me with DD hubs is the ability to Regen.
It might not put much back into the battery, but I really like the fact that it does put anything back at all. On my Fighter I typically see 3-6% Regen.
On an 80km ride (which my commuter should be capable of) that's an extra 3-5km distance. To me, that's nothing to laugh at.
DD hubs also allow easier over volting/amping without risking damaging the gears/clutches, key/keyway found in geared hubbies. There are countless reports on ES of people stripping gears, damaging clutches etc when over doing it with geared motors.
Granted there are also tons of reports of damaged DD hubs, but typically (at least from what I've seen) they take much more power before failing in comparison to geared hubs.

If your worried about noise, there are still a few options for using a DD hub.
You can oil cool it, dampening down the noise significantly.
You can use a sine wave controller. These are much quieter than our typical Infineon based controllers, but currently a bit more pricey.
You could do both for an ultra quiet result.

Cheers

 

[Cowardlyduck]

Ran the numbers again, and based on the degradation I was seeing with my LiPo on the Fighter. I can actually only expect about 1kwhr usable from these packs.
Still good enough for now I suppose, but very disappointed in these Zippy Compacts overall.

Anyway; anyone else have any opinions on which bike I should convert? I'm just waiting for my old Subaru Outback to sell (just bought a Hyundai Santa Fe to replace it ) and then I'll be pulling the trigger on the parts for this build.
At this point I will be going with the road bike, with the DD hub already mentioned. Unless anyone can point me to a better deal for a similar set-up.

Cheers

 

[TheBeastie]

The main draw card for me with DD hubs is the ability to Regen.
It might not put much back into the battery, but I really like the fact that it does put anything back at all. On my Fighter I typically see 3-6% Regen.

When looking at a recent thread at what kills lithium batteries, one of the utmost points of loosing life cycles was heat generation in the lithium cells.
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=57084
I am of the view that any gains you get in distance you ultimately loose in life killing of your battery. Because when riding/discharging the cells they warm up and then when regen is engaged via the DD motor its suddenly pumping huge amps into it all of a sudden causing a double whammy on heat generation thus killing lithium cells faster.

If the regen could be put into a super capacitor like on F1 cars then it would be great but until then it is just a battery killer to me and I would prefer the efficiency of a freewheel rolling momentum of gear motor.

 

[Allex]

One could always limit regen to a specific value - not killing the battery.
But you have a good point there: what is better, a DD with some drag but have regen to save you 4km or Geared motor which will consume less energy because it will be easier to pedal along(could be same 4km gain in the on of the run)?

 

[Cowardlyduck]

Some good points about Regen there.
From what I've seen, I don't believe the bursts of 300-600W Regen I do would be enough to significantly reduce the cycle life of my batteries. Sure if they're hot already, pumping Regen current in isn't going to help, but that's not an issue with Regen itself. The issue in that case is thermal management of the cells. Cells shouldn't be allowed to get that hot in the first place and if they are, too much current is being drawn from them for their C rating IMO.

True point about a geared motor potentially giving just as much increase in range from it's lower drag. I honestly don't know which one would come out on top. Could even be the same.

My preference is still for a DD hub that can Regen though. The other important fact (to me) that I failed to mention is the extra braking force it gives. On this build I only have rim brakes, which are only just sufficient for the bikes in their current form. Once I add 10-15kg of kit for the conversion I don't really want to be only relying on the rim brakes to stop me. Regen should save the brake pads from wearing out as fast, and be my primary form of slowing down when prepared.

What would be awesome is if someone made a geared hub that could also Regen. Whilst difficult, I think it's possible if they could make it disengage the freewheel/clutch when Regen is is activated.

Cheers

 

[Hyena]

I've used both DDs and geared hubs pretty extensively. I'm an equal opportunity hub motor killer :lol:

Regen braking IS a nice feature to have on a commuter and on my own geared commuter bike I do miss regen down long hills. The recovered power is trivial and dare I say insignificant but it's saving on brake pads that matters to me. The first thing I notice on a geared bike is how much I need to be using the brakes and on a daily ridden high speed commuter you chew through pads pretty quickly (and more annoyingly in my case, warp rotors)
You CAN weld up the clutch in a geared motor to get regen, it's on my list of things to get around to one day but I haven't found the time as yet. I can't imagine the drag would be any greater than a DD hub and you still benefit from the smaller size, lighter weight and increased torque. They would have the louder geared motor whine all the time though, even when coasting.

Otherwise everything else about your situation points away from DD motors.
A: You've got a 6 fet controller - this won't feed enough power to DD motor to make it perform any better than geared motor
B: You've got tired batteries that won't like giving up current anyway. A geared motor that sips away at the current is the way to go
C: You don't want to go that fast anyway so given the above again a geared motor is suitable. A 10t mac on 18S will give you a top speed of around 50-55km/hr with good torque and rarely pulls more than 20A.

 

[rp3]

I think you'll find going from the plush ride of the Fighter to a non-suspension bike is going to be very uncomfortable at the speeds you want to do. :wink:

 

[e-beach]

I think you'll find going from the plush ride of the Fighter to a non-suspension bike is going to be very uncomfortable at the speeds you want to do. :wink:

Uncomfortable is a very polite way to put it.... :lol:

Every time you go over a small bump it will feel like a bomb went off underneath you. And the larger bumps.....well if you don't remember the "kidney belt", in off road motor cycling then you may get a bit of a taste of what they were about.
The "uncomfortable ride" is why I got rid of my rigid Trek 800 for a bike with front suspension. I am now (slowly) putting together a full suspension Pro Flex 757 because the front suspended bike is still too rigid for my city streets. They are just......well.....frocking uncomfortable! :lol:

If you go with a rigid bike pick the one with the ability to put big under-inflated tires on it so the ride doesn't rattle you asunder.

My 2¢ worth.....

 

[Cowardlyduck]

Thanks for the feedback guys.
Bumps/comfort isn't such a big concern for me. I already occasionally ride the road bike to/from work via the same route, and it's fine. Yes I understand the higher speeds make smaller bumps more significant, however I live in Canberra, the land of bike paths. The bike paths here are the best in Australia, and I don't foresee any issues with bumps/comfort on the route I normally take.

Otherwise everything else about your situation points away from DD motors.
A: You've got a 6 fet controller - this won't feed enough power to DD motor to make it perform any better than geared motor
B: You've got tired batteries that won't like giving up current anyway. A geared motor that sips away at the current is the way to go
C: You don't want to go that fast anyway so given the above again a geared motor is suitable. A 10t mac on 18S will give you a top speed of around 50-55km/hr with good torque and rarely pulls more than 20A.

Thanks for the feedback Jay.
A: I'm actually not too concerned about performance with this bike. It just has to get up to speed eventually, and be able to maintain it. I'm ok if it struggles up hills. Guess you could call me a power weenie. :lol:
B: As with A:, I won't be pulling much current, so not a big concern.
C: According to the simulator, with a 12S pack, it's a little slower than I originally wanted, but fine for a commuter being ridden on bike paths daily.

Cheers

 

[TheBeastie]

If the regen could be put into a super capacitor like on F1 cars then it would be great but until then it is just a battery killer to me and I would prefer the efficiency of a freewheel rolling momentum of gear motor.

Decided to look around to see where ultracapactors are at in terms of price etc, not too bad really, fair amount of stuff on ebay.
This ultracapactor kit kind of seems ideal for a temp storage of DD break regen energy. "1500 Farad KIT Ultracapacitor Engine Start Booster Battery"
http://www.ebay.com.au/itm/1500-Farad-KIT-Ultracapacitor-Engine-Start-Booster-Battery-Eliminator-Car-Audio-/301059034609?pt=US_Motherboard_CPU_Combos&hash=item4618844df1&_uhb=1
http://www.ebay.com.au/itm/15V-233F-Ultracapacitor-Engine-Battery-Starter-Booster-Car-Ultra-Super-Capacitor-/181238407263?pt=Battery_Chargers&hash=item2a32a6a05f&_uhb=1
This is something I would like to see in high end bikes like the stealth, even if it was an optional extra.

 

[Kike Ming]

Cowardly Duck, Great information about regen with DD. I did not even consider possible battery damage from heat, with the reverse power transfer back into the battery. Is it really high enough to do damage? ( maybe on a really heavy bike ) Beastie, your ultracapacitor idea is awesome! I didn't know such a thing even existed. I'd like to chat about that with you, before my next build.

 

[TheBeastie]

Cowardly Duck, Great information about regen with DD. I did not even consider possible battery damage from heat, with the reverse power transfer back into the battery. Is it really high enough to do damage? ( maybe on a really heavy bike ) Beastie, your ultracapacitor idea is awesome! I didn't know such a thing even existed. I'd like to chat about that with you, before my next build.

While I have an electronics cert from way back in the day I have never really used it nor am I worthy of instructing in an engineering role.
The core cool thing about any capacitor is its ability to absorb and discharge electrical energy incredibility quickly, and they have arguably limitless charge and discharge cycles because they are kind of solid state as in there are no chemical reactions going on inside like regular batteries.
This puts ultracapacitors front and center for storing braking energy.
Thought this video was cool to demonstrate the stored energy http://www.youtube.com/watch?v=5hUxCYixoE4
This guy is using them to start his car http://www.youtube.com/watch?v=z3x_kYq3mHM
http://www.youtube.com/watch?v=8miq6sDy0wA&feature=em-hot-vrecs
This guy got a nice little ride on his electric scooter http://www.youtube.com/watch?v=exwd-tswyzA
Ready to go 48v version http://www.maxwell.com/products/ultracapacitors/products/48v-modules

I have no idea how much its been looked into with ebikes, never noticed any posts on ES forum about it, might start looking around now.
I guess the issues are extra cost and nerd factor of only a small amount of people enjoying the thought of giving their batteries a longer life span.

Maybe we should post a myth to Mythbusters asking "is it true that ultracaps on ebikes double your range in regen energy compared to regular lithium battery regen? and give your lithium batteries a longer life span?" and get them to do all the lab testing and hard work, would be an enjoyable episode to watch.

 

[Allex]

Wzup?
I Will build a bike for my girlfriend, so she can keep up with my Bomber!

I just placed a order at Pauls:
Mac 500/1000W Motor in Alex Wheel
- Wheel Type: 26" DM24 Disc
- Motor Speed: Upgrade Rear 320rpm, 8T MAC500WH
Grin Tech Rev4 Rear Torque Arm
EM3ev Disc Spacer
EM3ev Triangle Battery Bag
Thumb Throttle
DNP Extractor Tool

 

[Cowardlyduck]

Good stuff. Your faster than me. I am still yet to order my parts...still trying to sell my car to fund this build.

 

[Cowardlyduck]

So, this build just took a massive change in direction...for the better.

I finally sold my car a little while ago, but before I got around to ordering all my parts to start the build, one of my mates decided to buy a new recumbent. Thankfully for me that meant his wife made him sell his old one...to me.

So I'm now the proud owner of an early 90's BikeE in mint condition (for it's age).

Obviously the plan is to convert it, however I'm planning on taking on a challenge in converting this that I haven't yet seen anyone else do.
All the other conversions so far have placed the batteries either on top/underneath the main frame (between the riders legs) or on the rear extension of the frame.

It seems to me the obvious, and best place to put the battery is inside the frame itself. I won't be able to use my existing batteries as originally planned, however I'm more than happy to build a new pack to make this build a super slick one.

A few quick rough measurements, and test fittings seem to indicate, I should be able to do an 18650 based 15S 5P pack. It will be 2 wide up to just before the rear stay mounts, and 1 wide through the rear stay mounts.

It will need to be a tight fitting, with minimal to no padding and some heat shrink, but thankfully 18650's are pretty tough...at least in my experience.

I will need to drill out the rear stay mounts as they appear to be riveted on. I'm hoping it's not an issue to just re-attach these mounts using bolts afterwards. Can anyone see why this shouldn't work?
The other catch is I will likely have to re-route some, if not all, the gear/ brake cables externally, however seeing some cables run down the outside of the frame is nothing compared to seeing some batteries hanging off it.

I'm leaning towards potentially using some Panasonic 18650B 3.4Ah cells for this one since they will accommodate the best capacity. With 15S 5P (75 cells) that's over 940Wh. Probably more like 800Wh usable, but still that's epic for being completely invisible. I don't know of any other E-bike out there with that much capacity completely hidden.

I think the rest of the build will still be the same. I've already got the 6 Fet (beefed up) EB3 Controller, which I might attach directly to the frame for heat-sinking.
I am considering getting a visually smaller hub motor like a Cute...to make the build completely invisible. Is there other small hubbies I should consider?

Cheers

 

[Allex]

That will be a super geeky ride for sure

 

[Cowardlyduck]

That will be a super geeky ride for sure

Thanks.
I also realised, yes the 18650 cells side by side are a super tight fit (as in the picture), but I can stagger them slightly to reduce the width by a few mm. That will help them sit snugly together, and allow for a little extra padding on the sides.

Cheers

 

[The fingers]

Nice blue color. 8)