Sprocket Options?

[LI-ghtcycle]

Heya all, I have a Golden Motor in-runner with a 14mm keyed shaft, and the current sprocket is designed for 420 motorcycle chain. Given that such chain would be over-kill and too wide to effectively squeeze around the pedal chain in my dual RH side drive, I have a couple of options.

1) Grind down the current sprocket until it is narrow enough for 1/8 bicycle chain (it has a 1/2 inch pitch, so it will work)

2) Source a off the shelf sprocket (I want to do this anyway, because it's a pain if I have to fabricate sprockets)


I haven't looked TOO hard for a off the shelf, but I'm kinda clueless who would sell one, I have looked at a few scooter and other suppliers, but most I see are either in standard sizes (yeah I know 9/16 inch is really close to 14MM, but I'd rather have something fit tighter) on the shaft, and too large of tooth count, (I need 9T at the moment) or not the right chain pitch/size.

Any suggestions welcome!

 

[AussieJester]

I would actually go ThudSTeR route piss off the original sprockets and run Kart sprockets/chains
you get a good selection of sprockets and the chain is upto the task of the Golden motor.

All the best

KiM

 

[neptronix]

when you say golden motor, do you mean that > 20lb thing that's rated for 5kw or 10kw?

 

[LI-ghtcycle]

when you say golden motor, do you mean that > 20lb thing that's rated for 5kw or 10kw?

Not quite, more like 650W (I will be running more than double that wattage peak) .... and 19.5 lbs!

It is very compact though, but it also has a bit more cogging than I would like, but it should never be run with out at least a tickle of throttle, since it's going to be so efficient.

 

[LI-ghtcycle]

I would actually go ThudSTeR route piss off the original sprockets and run Kart sprockets/chains
you get a good selection of sprockets and the chain is upto the task of the Golden motor.

All the best

KiM

Hmmm good idea thanx!

Only trouble is I already have a 410H (bicycle 1/8 inch) sprocket on the NuVinci, so if I can, I'd like to stick with the same 1/2 x 1/8 inch size bicycle chain since this is a high torque but not huge watts set-up, max will be 1400 watts peak, more like 300 - 500W constant.

I will see if there is any go-kart sprockets that would have the right 1/2 pitch that would bolt on.

 

[bobc]

9 teeth is less than you'd want in the ideal world - I really would go for a smaller pitch chain if you can sort the engineering. There's lots of ways of fitting the sprocket if you can do any machining, I like to make DIY taperlocks, or taper the shaft & bolt the sprocket on to the end (threaded hole in end of shaft) - grubscrew if you must ;^)
A 9 tooth sprocket will be noisy, inefficient & wear quickly. On our greenpower cars we use 1/4" chain & it's fine with just the one kilowatt - the small motor sprocket lasts for about a season (say 1000 miles). That move from 1/2" to 1/4" chain coincided with 10 miles added to our PB & getting into the top 5 in the national final....i.e. promotion from worthy competitor to contender
There are several suppliers ofsprockets & timing belts in UK, there must be loads in the states
I've not inspected a nuvinci but a smaller pitch sprocket can easily be bolted to the teeth of the 1/2" sprocket you have - checkout this thread on the greenpower forum
http://www.greenpower.co.uk/forum/discussion/784/mounting-a-big-sprocket-on-a-little-one.

 

[LI-ghtcycle]

9 teeth is less than you'd want in the ideal world - I really would go for a smaller pitch chain if you can sort the engineering. There's lots of ways of fitting the sprocket if you can do any machining, I like to make DIY taperlocks, or taper the shaft & bolt the sprocket on to the end (threaded hole in end of shaft) - grubscrew if you must ;^)
A 9 tooth sprocket will be noisy, inefficient & wear quickly. On our greenpower cars we use 1/4" chain & it's fine with just the one kilowatt - the small motor sprocket lasts for about a season (say 1000 miles). That move from 1/2" to 1/4" chain coincided with 10 miles added to our PB & getting into the top 5 in the national final....i.e. promotion from worthy competitor to contender
There are several suppliers ofsprockets & timing belts in UK, there must be loads in the states
I've not inspected a nuvinci but a smaller pitch sprocket can easily be bolted to the teeth of the 1/2" sprocket you have - checkout this thread on the greenpower forum
http://www.greenpower.co.uk/forum/discussion/784/mounting-a-big-sprocket-on-a-little-one.

Yeah, I'm going to want to eventually go with a larger sprocket on the motor to avoid noise and wear, but for my current sprocket on the NuVinci, this 9T should be in the range I need for the speeds I want at least to do some initial testing.

Once I get some custom sprockets made for the NuVinci, I will go with #25 chain so I can have a much higher tooth count at the motor and wheel for less noise and wear, but that will mean some custom one-off sprockets. I might be able to make a sprocket adapter out of the current sprocket, I guess I could see if there is a #25 sprocket that would bolt onto the motor.

I'd much rather have a hole pattern than bolting to the teeth as it's very narrow between the NuVinci and the freewheel for the pedal sprocket.