Miles' Project 1 [eMoulton]

[recumpence]

I am just about ready to start machining the box.

So, projects 2,3, and 4. Don't you mean 002, 003, and 004?

Matt

[Miles]

So, projects 2,3, and 4. Don't you mean 002, 003, and 004?

I love the initial development stages of a project the best, I think - starting with a blank sheet

[dennis]

I'm curious, do you have a picture of your backpack battery to share? I am currently working on a backpack battery for my Bionx kitted Mu SL.

[Miles]

Hi dennis,

The batteries are just loose in a laptop backpack, with a coiled lead to the bike. I haven't given much attention to this area, yet....

[dennis]

Thanks for the Pic. Nice sleek covert power unit.
On some of my extended test rides, I found too many Ah's is never enough and 18 AH's of juice is gone in the blink of a eye. Plus, it's a real pain swaping the Bionx stock batteries carried in my backpack. With my new after market battery pack, I plan to carry up to 40 Ah's of LiFEPO4 at 36V in parrallel in a heavy duty backpack. Pic:

IMG_0620 (Large).JPG (59.31 KiB) Viewed 1848 times

[Miles]

Hi Martin,

It comes as a kit, with the cranks. I got mine from Strida Netherlands, who have now taken over the whole of the European distribution network.

http://www.strida.nl/vouwfiets_contact/

Maximum diameter is 263mm

[Miles]

The Strida pulley is 100t. How about the CDrive, which you can get in 80t and 60t?

[Miles]

http://www.torquetrans.com/pulleys/cust ... ulleys.htm

[Robbie Hatfield]

The only drawback if you can call it one that I see is it looks like getting the wheel off of the back in order to fix a flat tire might be troublesome?

Robbie

[Miles]

Hi Robbie,

In practice, it's not much more trouble than dealing with a normal derailleur set-up. Detach the "Click-box", loosen the axle nuts and push the wheel forward, then slip the belt off the motor pulley and it drops down and hangs out of the way below the large pulley, leaving you free to remove the wheel as you otherwise would.

[es2150]

What size wire is in that coil? i figured out what size wire to do for hub motor and 50amp controller and came out to an 8 for 5ft tether. have since gone back for commute just because I wanted to loose the heavy backpack. I was carrying 48v 15ah lifepo4 about 15lbs plus 5lbs kit = 20lbs backpack. It was great for offroad but too much for commuting. Anyway, I had similar coil wire but thought size was way to small, am I mistaken. By the way, your rig is literal a work of engineering art. I am assuming you are using lipo right. Do you ever have any concerns about discharge rate and having in backpack?

[Miles]

Hi es

I'm still using 36 5Ah high power density NiMH cells... The lead is from an electric kettle - 15 amp rating, I think. I'll check the gauge.

Maybe doubling up conductors is the way, for a ready-made coil?
http://www.cablescience.com/retractile_cords.html

Backpacks work better for a stretched-out riding position - I forget mine's there after a few seconds - mind you, that's only 5lbs weight of batteries... say 7lbs total weight .

[Green Machine]

Really sweet build...

Too bad you cant mount rack your batteries to finish it off...

I really love this battery for my downtube folding bike build:

http://ebikessf.com/50v10ah-lipo

I have 3 of these and swear by them..really a tight package...i think would fit stealthily on rear rack.

[liveforphysics]

Hi es

I'm still using 36 5Ah high power density NiMH cells... The lead is from an electric kettle - 15 amp rating, I think. I'll check the gauge.

Maybe doubling up conductors is the way, for a ready-made coil?
http://www.cablescience.com/retractile_cords.html

Backpacks work better for a stretched-out riding position - I forget mine's there after a few seconds - mind you, that's only 5lbs weight of batteries... say 7lbs total weight .

Have you felt the extremely supple ultra-fine-strange silicone 8awg wire Miles? I think you may find a cable made from twisting a pair of 8awg silicone wires together, and fixing a fine elastic bungee to some point of the cable which you don't expect to be needing to drawn from the backpack, so it keeps the slack all tucked away when not needed, but if you change positions or dismount or whatever to require additional slack, you've got an extra few foot loop that the be drawn out from the backpack by stretching the bungee.

I think you may find something similar to that to be an even less intrusive backpack-bike cabling approach, gaining high-current capability.

[Miles]

Really sweet build...

Too bad you cant mount rack your batteries to finish it off...

Thanks. I may fix the batteries to the frame on the next build. There are real advantages to having them in a backpack, though. IMO, on a rack over the rear wheel is the worst place for them....

[liveforphysics]

Really sweet build...

Too bad you cant mount rack your batteries to finish it off...

Thanks. I may fix the batteries to the frame on the next build. There are real advantages to having them in a backpack, though. IMO, on a rack over the rear wheel is the worst place for them....

I agree. For smallish sized packs, backpack makes a lot of sense. Backpack with a compact, quiet, high current opertunity charger and a few Nano-tech packs able to be charged in 6mins makes boatloads of sense. Even if you only have a couple hundred watt-hours, you can really leverage them well with a setup like that.

[Miles]

Have you felt the extremely supple ultra-fine-strange silicone 8awg wire Miles? I think you may find a cable made from twisting a pair of 8awg silicone wires together, and fixing a fine elastic bungee to some point of the cable which you don't expect to be needing to drawn from the backpack, so it keeps the slack all tucked away when not needed, but if you change positions or dismount or whatever to require additional slack, you've got an extra few foot loop that the be drawn out from the backpack by stretching the bungee.

I think you may find something similar to that to be an even less intrusive backpack-bike cabling approach, gaining high-current capability.

Good idea... That would be a lot neater.... Thanks for the prompt, Luke.

[liveforphysics]

I don't know if the quality of this wire matches the suppleness of the HK stuff, but it's local to you evidently.

http://cgi.ebay.com/8-AWG-Silicone-Batt ... 1403wt_905

I figure you would want both wires black.


Then something like this:

http://cgi.ebay.com/20-Ft-1-16-ID-Tiny- ... 116wt_1139


Then a premium connector that would never disconnect unintentionally, but could disconnect from a firm tug in the event of a wreck or forgetting to disconnect. I'm thinking EC3 would be a good match for your needs, while having ample current overhead.




And then of course no BMS or balancer in your pack, as you're responsible, and neither savage nor fool. Batch charging from something like this 755w 48v compact server power supply would likely tuck nicely into the backpack and enable very useful opertunity charges.

http://www.serversupply.com/products/pa ... ?pid=86912

[liveforphysics]

BTW- I only posted those links for Miles because of the irony of linking something I found online to Miles, the king of all human/machine search engines.

[Miles]

Good stuff...

Thanks Luke.

[Green Machine]

Really sweet build...

Too bad you cant mount rack your batteries to finish it off...

Thanks. I may fix the batteries to the frame on the next build. There are real advantages to having them in a backpack, though. IMO, on a rack over the rear wheel is the worst place for them....

Hi Miles,

Its interesting you say this..and i am not knocking the idea of backpack at all since i havent tried it, but am contemplating a new build and a back pack battery could be a consideration although a distant one.

I love your bike and is one of the nicest aesthetic e-bikes i have seen in picture...i know you probably spent a bundle...again well done.

SO i have 4 high end bike builds, and it turns out my cheapest one...a downtube 20 inch wheeled folder is my favorite...i put 1300 miles on it so far in 4 months. I call it my beater...of all my bikes its the one i can lock outside and not worry cuz its low key looking. I love it and cant put my finger on just why. It had thin tires like yours and i went with schwab fat apples and disc brakes and that made a big difference. I hated those thin racing bike tires on a ebike especially since mine is front wheel drive. When i put the fat apple tires on it (amazingly they fit) my love affair started with this bike. I also ended up loving the front wheel drive (it spins out on start up but is fine all other times) and internal hub shifter on the back. I just love the 20 inch wheels on a road electric bike, and because of the fat tires i am able to ride off road on fire trails. Mostly i love the low center of gravity that having the battery mounted above the rear wheel has compared to full sized bikes with the same configuration i own. Because i never have to lean the bike over because of the low downtube i never feel the extra weight of the battery on the back, and because of motor on front it is well balanced. It just doesnt feel like an electric bike like my large frame bikes do. I use the topeak small dxp bag which is pretty aesthetically nice because it is so small (fits 10ah pack perfectly) and i like having the side panniers for extra stuff on my rides. I dont like to have anything on my body when i ride including in my pockets...i got spoiled always having rear topeak bags on all my bikes.

Anyway i think a 20 inch wheeled bike is a nearly ideal electric bike build...and i rarely see one...and yours is sweeter than sweet.

For a while i was thinking of spending the money on a quality 20 inch wheeled frame and moultons were one of the bikes i look at.I have never had my bike folded and dont need the folding function...so a moulton would be perfect except for the price point (1700 is as cheap as i can find a starting bike here in california).

So why do you not like a rear mounted battery? Is it asthetics? Or functionality? Is it a balance thing? Like always...just gathering info...

[HAL9000v2.0]

Miles, do you need 498 pcs? I'll take two...
http://www.diytrade.com/china/4/product ... _cord.html
http://www.alibaba.com/product-gs/31085 ... cable.html

I googled this before for some time but never find anything bigger then 3 x 1,5mm2. I'll be happy with 4 x 1,5mm2.

For now I am using guitar coaxial cable. it is good up to 40A.

http://www.amazon.com/dp/B003NE5WO4/ref ... B003NE5WO4

[Miles]

SO i have 4 high end bike builds, and it turns out my cheapest one...a downtube 20 inch wheeled folder is my favorite...i put 1300 miles on it so far in 4 months. I call it my beater...of all my bikes its the one i can lock outside and not worry cuz its low key looking. I love it and cant put my finger on just why. It had thin tires like yours and i went with schwab fat apples and disc brakes and that made a big difference. I hated those thin racing bike tires on a ebike especially since mine is front wheel drive. When i put the fat apple tires on it (amazingly they fit) my love affair started with this bike.

I'd prefer it if I could fit sturdier tyres on mine but using the Stelvios was the only way to create enough space for the motor

So why do you not like a rear mounted battery? Is it asthetics? Or functionality? Is it a balance thing? Like always...just gathering info...

Mostly balance. On the Moulton, the best place to mount them would probably be under the tie rod for the cruciform.

I have to carry my bike up and down steps whenever I use it. Having the batteries in a backpack makes the bike itself an easy lift.

[Miles]

Miles, do you need 498 pcs? I'll take two...

I'm leaning towards Luke's idea at the moment, perhaps with a sprung cable reel, even

[Miles]

On the Moulton, the best place to mount them would probably be under the tie rod for the cruciform.

Something like this...