Robjohnb

I've seen a tension measuring device but I'm sure pinging is just as good. How "true" were you able to get the wheel? I cannot seem to get better than 2 or 3mm. I think this is where the skill comes in.

oh, ok. I used the "tapping tone" method to try and equal the tension. No problems so far.

Just enjoyed reading this thread. I too built a commuter e-bike. Based on full suspension hybrid. Was surprised about broken spokes, can they be over tightened?

ok, looks like cost is your key here. Seems a heavy bike though. My effort cost about £400.

HobbyKing, looks good, thanks. Have you also used a BMS for them? From my avatar picture, I have 40 li-ion cells wired 10s 4p. Taken from laptop battery packs. No idea what peak current it can deliver, it does sag somewhat on the hills. How are you finding the Zippy packs?

Had a further search on the web and appears these are 6 lipo cells at 3.7V (4.2V max) 2100mA each cell. As a pack, 11.1V (12.6v max) at 4200mAh. Additionally, wiring only good for low current and there's no cell balancing (BMS). Thanks for the feedback though.

Is that the russian speaking youtube clip? if so, the cells as you say are 2100ma (guessing at 3.7v). But how many cells in the pack? 3x4?

Thanks for the comment. If it can deliver 9.8amps at 12V (will use 3 in series) I'll be very happy. My existing pack is 7.2amps/36V feeding a BMSbattery Q100H, some sagging on hills.

Does anyone know if these ebay battery packs deliver the capacity as stated? http://www.ebay.co.uk/itm/111460971343?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Regards, Rob

Also done, Rob

Have been using the e-bike for several work commutes now and achieve the 11.5miles in 50mins. Typical PAS speed 18-20mph (limiter to be set :-). Above this, the motor Q100H 36V 201rpm on 700c seems to run out of drive. I calculate 201rpm to be about 15mph for 700c. So with PAS the 201rpm goes up a little. Is using a higher voltage an option? Has anyone tried?

Seems to be a lot of discussion on the web about whether the CE mark alone is sufficient. Loosing interest now. In the eye of the law if summoned to court, I would like to think that if a light was purchased from a reputable shop and fitted working correctly this would not go against you.

Hmm, please elaborate ?

I'm the owner of the e-bike referred here and the intention is to be legal. Just had a look at the rear light and it is CE stamped.

Some degree of caution was needed when building the batt pack. A lot of energy there and easy to start a fire. Opening up PC laptop packs is not straight forward either. Only attempt this if you're 100% sure of all risks and familiar with electronics. Rob

Thank you, what would you like to see? It's pretty basic construction. The batt pack is 40 1800mAh lith-ion cells. These are 10 series by 4 parallel, giving 37V at 7.2Ah. There is a BMS for charge and discharge. Batteries fitted into some square PVC drain pipe! this slotted nicely into the drink bottle holder then some velcro strap at the top of pack. Regards, Rob

Yes, Q100H 36V, LSW-675 controller. I have logged some ride data using the sports-tracker app. Need to make the data public then anyone can view online. Rob

Hello Pedelec's Just joined the forum and thought I would share my DIY e-bike build if anyone is interested. The e-bike parts are from bmsbattery.com, fitted to a Ridgeback momentum bike. The battery pack is home brewed from 5 pc laptop battery packs, 40 lith-ion cells plus the BMS. 270wh. Have done 12 mile commute in 50mins, ave speed 14mph with little effort. Mostly pedal assist. Regards, Robert