After much internet browsing all the hubs and premade kits seemed so expensive. So just for fun I set a £100 limit to see what it got me. If I liked the results of electric assistance I planned to upgrade and pass on the prototype to the girlfriends bike.
My front forks are 20mm so no hub would go there anyway and having a rear one meant more expense downgrading parts like gears. I was adamant that I would not lose my 9 gears and rear disc and wanted a cheap conversion for small commutes and fun. Well I did 30 miles on this the other day to get a before conversion time lol. Nearly 2 bloomin hours and allot of sweat.
Here is my parts list I used to convert my bike
all prices inc delivery
MY1016 24V motor 19.99 new
http://cgi.ebay.co.uk/24-VOLT-250-WATT- ... 105wt_1031
350w 24v contoller £11
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 765wt_1392
7kg each 12v 24ah deep cycle lucas gel x2 best offer £48 delivered(turned up 3 years old and both dead revived to 20ah and refunded half the cost via ebay)
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 2203wt_782
Throttle cut down to grip shift size £7
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 969wt_1928
£10 for a 90t minimoto sprocket, £3 for a chain. For an average bike all that would be only £100 but I spent around a further 50 on convertings my 20mm axle forks to accept quick release wheels, aluminium plates,clamps and bolts etc. Including my refund for bad batteries or if you bought smaller ones you could do this sort of project for £75. I got a 16t freewheel to fit my sprockets 54mm hole perfectly and line up with the bolts like it grew there but didnt want to spend £30 on a cheap wheel with disc mount on one side and screw on the other just incase it didnt fit in my forks. Rear bmx hubs or track hubs (110MM O.L.N) are perfect for any other front forks but mine as I have super fat legs that rub on the freewheel and 20mm axles. So for now I settled with no freewheel as my motor draws 9amp hours and I easily have two hours run time plus a backup lithium-ion to keep it spinning, I have left it a direct constantly engaged drive.
All above has been mandatory but optionals include £50 charger/balancer imax b8, £15 7ah li-ion 12v, £10 indicators, £10 motorcycle generic handlebar switch (horn, lights,indicators and motor kill switch), £15 20w leds 1600 lumens. The charger runs from 12v sources like car batteries, solar or mains adaptor meaning i can charge at my destination or top the batteries up at my destination with 3.5ah each to stop sulphation with my 7ah lithium (3inches x 2inches little thing). I also got a 9 tooth sprocket to hit the magic 10/1 ratio. I figured that at 20mph 26 inchers wheels do 250rpm x10= 2500rpm at the motor, but due to my massive tyre Im still stuck at around 2000rpm not closer to 2500 as has been sugested is good for a my1016. Untill I find a better wheel il use vbrakes while the disc is otherwise occupied lol.
So far my furthest test has been 7 miles at wide open throttle at 18mph. The dodgy batteries used to sag around 3 miles on first ride but now they are run in are still pulling well even after 7 miles. Id estimate 15-20 miles max on my dodgy batteries as 7 miles took them from 12.9v to 12.6. For now the batteries are in a laptop bag belted to the frame and seat post and are surprisingly secure. In the bag is an old datatool system 3 motorcycle immobiliser that activates the indicators when you arm it (when they arrive) and screams bloody murder if you touch it at all. I will wire this to the ignition lead so no kids can muck about with the motor until i get a key switch.
The motor does not overheat and so far, on the flat, it gets as warm as a cup of tea at most. I live on the coast so havnt tried hills but can tell you now this will be absolutely useless going up gradients as it is geared to do 17mph and offers no torque even against very strong winds. Ah well its all good fun, Perhaps I will try to modify the motor to take my 6 tooth sprocket and replace the already home made custom 9 tooth one to get some more torque. For me though its all about getting from a to b as fast as possible without getting arrested or spending cash lol Take it easy Dan