Mines a 250 watt 24v hub kit
I have a 250watt hub kit (24v)
Well I am sitting here watching and waiting for my battery to recharge (a watched kettle never boils!) . Then I can take advantage of the rain having finally stopped!
I have read and re-read all the posts on this forum that seem of interest and now I thought I’d write my own whilst waiting for the charger to turn from red to green.
I had been thinking about an electric bike for some time and had read many forums and checked out many ready built and kit bikes that were for sale. I had also come across quite a few videos abnd had watched some very impressive (and some very dangerous) looking bikes and kits.
I was initially thinking about a Currie Electrodrive kit - but was put off by the battery casing being fitted into the triangle of the frame, as it turned out my 18” frame would have been too small anyway. Also the motor, being fixed to the side of the rear wheel didn’t really appeal to me. I decided on a hub kit instead. The area where I live has more than its fair share of ASBO collectors and I figured that if I had a bike that looked electric then it wouldnt be long before the little herberts made an attempt at pinching the bike either from my garage or wherever I locked it up.
I eventually found a supplier and ordered my hub kit. I knew that the hub was 140mm wide and so I searched for a secondhand bike to fit it on. I bought a secondhand Raleigh Max MTB on ebay for £40, it was 26" wheel on an 18" frame. The handlebars and saddle were easily raised and still within their 'Safe markings'. This helped keep the weight down rather than a 20" frame. I did not want aluminium as I knew I was going to have to spread the rear wheel spacing and perhaps do a bit of bending (the bike, not me).
I found a link somewhere to “Sheldon Browns frame setting” guide. It proved quite useful rather then just stretching the rear frame apart and hoping that each side were equidistant (is that a real word?) It didn’t take too much effort at all to get the 140mm spacing from the 130mm original spacing between the drop-outs, but anymore would have either fouled the pedals or misaligned the bike chain.
The kit was a 250 watt rear hub kit with a 24volt 6.8ahr Li-ion battery. The controller (15amps) was fitted in a plastic housing which was supposed to fit the bikes frame where the water bottle would normally be fitted. It didnt fit well and left too many wired connections exposed which were supposed to be taped up, 4 from the throttle, 8 from the hub and a load of surplus wiring from the controller all taped up just above the crank, yuk!. Also the battery itself came with a quick release fitting that should fit to the saddle stem, but didn’t without padding out the stem with loads of insulating tape, yuk! -
My next problem was that the kit came with a twist-throttle and I already had two twist fittings on the handlebars for the front and rear gear changes. I didn’t fancy a thumb control throttle so I decide to remove the crank chain gears twist control and just leave the 5 rear sprockets functional and put the throttle on right-side handlebar. I left the chain on the largest chain wheel as I very rarely changed this gear anyway, finding the rear 5 more than adequate for my purposes. I moved the rear sprocket twist control from the right handlebar to the left side, works fine but now in opposite direction to change up or down (you get used to it, a bit like having cars indicators lever on the opposite side).
I then bought a cheap frame bag from Aldi (£3.99) and put the controller in that with all its wiring/connections it seemed tidier and more showerproof than the taping-up idea. I then found and old 'wash/shaving kit bag' which was just the right size for the battery - A bit of Velcro webbing soon made an effective and easily removable battery pack.
The problem was that although I could now easily remove the battery when leaving the bike, the frame bag had to be left on with the controller inside - it would have taken too many multi-pole connectors to make it viable to take the battery and controller off together.
Finally, I decided to ditch the frame bag idea and I bought an ‘eddystone’ enclosure box from Maplins. It was just the right size to take the controller and all its wiring and keep it all neatly (almost) waterproof. I drilled the underside of the box and fitted grommets to take the incoming wiring and just left the two power wires protruding from the bottom of the box with bullet connections for the battery. I also drilled two holes on the bottom of the box to bolt down to my rear rack and fitted two ‘u’ type screw brackets to further fasten it to the rack to prevent it from being pulled or ripped off. I have checked the temperature of the controller inside this box and it doesn’t even get warm at 24volts.
The wash/shave kit bag for the battery was a temp measure and I have since bought a rear rack bag from Halfords (now reduced to £18.99) which measures 30cm long x 15 cm wide x 15cm high. This easily took my 24v Li-ion battery and now takes my Powabike Windsor 24v NiMh battery as well as extras like padlock, lights etc. The bag came with a shoulder strap and is easily removed from the rack with Velcro straps. The weight of the bag/battery is no real problem. I have made up a connection for the battery wires to come through a small hole in the end of the bag with bullet connectors to fit the controllers. I used a male and female connector on the controller and on the battery (rather than two males and two females on each) to prevent any chance of connecting them the wrong way round.
I have found the new Windsor NiMh pack far better than my Li-ion pack - the kit gives me about 17mph (power only) on the flat and about 12 miles on one charge with very little effort at pedalling. I have only charged the Windsor twice since getting it earlier this week and will hopefully get even better range once the battery has been discharged and charged a few times.
So far its very early days to give a true verdict on the kit but for now (with the new battery) I am very happy with it.
I have linked a few photos below.
All the best, Richard
(Hopefully my battery is almost ready to come off the charger now!)
