I've read a lot about Pedelecs in the last few weeks so decided to give it a go. Converted my 7 year old Specialized Rockhopper with a used 8FUN kit. The conversion was tight Squeeze as the bike has a 17 inch frame. The Motor is a Bafang SWXK 250W with a 9Ah bottle battery. The first job was to fit the front wheel, first thing was that the wheel wouldn't fit in the forks and I had to file a small amount off the dropouts. Next thing was I have 160mm disk brakes and the wheel was hitting callipers. Onto Ebay and purchased a used 185mm disk for £10. Also bought the 185 adaptor(£8) which moves the calliper out to match the disk. The wheel had a plastic spacer fitted in place of the disk, I read somewhere that you should leave this fitted but I removed it to make everything fit. Refitted the front wheel and some of the spokes where still hitting the calliper. I managed to move the calliper about 0.5mm away from the wheel and all is fine, brake works well. If I was doing this again I would purchase a larger disk.
Plugged the battery in, connected the controller and switched on, operated the throttle and the wheel spun round, Eureka! I fitted the battery on the frame down tube in place of my water bottle, It was a really tight fit and hit the crossbar, but with a bit force it went in. After removing and replacing the battery a few times it is now easy to fit and remove as the mounting became a bit loose.
Couldn't wait to try it (better than Christmas morning as a kid) so fitted the throttle and selector/LED indicator to the handlebars, removed the pedelec sensor and shoved the controller in my saddle bag, wires hanging out everywhere, and took it for a test drive down the street using the throttle, brilliant it works! Although a howling gale and about -2 deg means I didn't go far.
Next job was to finish the bike off by adding the pedelec sensor and fixing the controller/plastic case to the frame, there was no way I was going to remove the bottom bracket to fit the sensor, and there was no space to fit the sensor on the chain side with the 3 chain rings. So I removed the LHS pedal (with an extractor I got off ebay) and found that the sensor mounting would not fit over the plastic part of the bottom bracket, so out with dremel and ground enough off the sensor mounting to make it a tight fit, refitted the pedal and tried pedalling, after trail and error I found that I had to turn the sensor 180 degrees to make it work, this involved drilling the mounting bracket and rotating/refitting the sensor. Final fitting was done with silicon sealant to make sure it wasn't going to move.
Now to finish by fixing the controller/case to the seat tube. I found that the plastic controller case would not fit as it was preventing fitting of the battery. Took a hacksaw to the box and made it 8mm smaller and everything now fits, just. The wiring was tidied up a bit, job done.
I have ridden the bike a few times now and it's brilliant. Goes about 14.5 mph according to my GPS which is fast enough, although there was only 25 psi in the tyres, they are now blown up so it's probably a bit faster. Bike weighs 21kg and I'm 65 kg so it performs quite well.
Just fitted the Turnigy power meter, I was going to remove the shunt and run small wires to the meter, but my battery cable was quite long and in the end I took the easy option and stuck the meter on the handlebars with tie-raps and chopped the battery cable and routed it to/from the meter, it works fine. I was surprised how good this conversion is, I tried it on a couple of hills which normally 'kill' me and it breezed up.
I think it's interesting to see some of the readings from my Turnigy meter. After about 7 miles of mixed riding on the flat, hills and throttle I had used 2.5Ah. I noted that using the throttle I am drawing around 6 amps at 14.5 mph on the flat. The highest current reading I saw on a steep hill was 16 amps, although I need to do some more testing now that I've blown the tyres up and have some reduced drag.
Derek
Plugged the battery in, connected the controller and switched on, operated the throttle and the wheel spun round, Eureka! I fitted the battery on the frame down tube in place of my water bottle, It was a really tight fit and hit the crossbar, but with a bit force it went in. After removing and replacing the battery a few times it is now easy to fit and remove as the mounting became a bit loose.
Couldn't wait to try it (better than Christmas morning as a kid) so fitted the throttle and selector/LED indicator to the handlebars, removed the pedelec sensor and shoved the controller in my saddle bag, wires hanging out everywhere, and took it for a test drive down the street using the throttle, brilliant it works! Although a howling gale and about -2 deg means I didn't go far.
Next job was to finish the bike off by adding the pedelec sensor and fixing the controller/plastic case to the frame, there was no way I was going to remove the bottom bracket to fit the sensor, and there was no space to fit the sensor on the chain side with the 3 chain rings. So I removed the LHS pedal (with an extractor I got off ebay) and found that the sensor mounting would not fit over the plastic part of the bottom bracket, so out with dremel and ground enough off the sensor mounting to make it a tight fit, refitted the pedal and tried pedalling, after trail and error I found that I had to turn the sensor 180 degrees to make it work, this involved drilling the mounting bracket and rotating/refitting the sensor. Final fitting was done with silicon sealant to make sure it wasn't going to move.
Now to finish by fixing the controller/case to the seat tube. I found that the plastic controller case would not fit as it was preventing fitting of the battery. Took a hacksaw to the box and made it 8mm smaller and everything now fits, just. The wiring was tidied up a bit, job done.
I have ridden the bike a few times now and it's brilliant. Goes about 14.5 mph according to my GPS which is fast enough, although there was only 25 psi in the tyres, they are now blown up so it's probably a bit faster. Bike weighs 21kg and I'm 65 kg so it performs quite well.
Just fitted the Turnigy power meter, I was going to remove the shunt and run small wires to the meter, but my battery cable was quite long and in the end I took the easy option and stuck the meter on the handlebars with tie-raps and chopped the battery cable and routed it to/from the meter, it works fine. I was surprised how good this conversion is, I tried it on a couple of hills which normally 'kill' me and it breezed up.
I think it's interesting to see some of the readings from my Turnigy meter. After about 7 miles of mixed riding on the flat, hills and throttle I had used 2.5Ah. I noted that using the throttle I am drawing around 6 amps at 14.5 mph on the flat. The highest current reading I saw on a steep hill was 16 amps, although I need to do some more testing now that I've blown the tyres up and have some reduced drag.
Derek
