a picture of one (the one I wanted...) on my electric bike

anyone building a car - this really is a godsend for you - the 8mm chain is just what you want & an 80 tooth sprocket will give you a wide choice of suitable ratios.
PS - this has replaced a 100 tooth sprocket - which is now also spare.... ;^)

I bevelled & cleaned the sprocket teeth on all these at the weekend so now they are ready to simply bolt on to a
http://www.chainreactioncycles.com/Models.aspx?ModelID=54209
8mm chain & motor sprockets are available from HPCgears, though their chain seems to be rather expensive - may be worth checking minimoto or pro_grade BMX. Rob on here was looking into this....??

Ah yes, I have been doing this the weekend in fact! It doesn't like BMX chian, have some Minimoto lying around somewhere, so I shall find it and try! I've also got my freewheel - which is a perfect fit! and will be putting some pictures up tomorrow afternoon.

Rob

If I'm reading the HPC price list correctly they're charging over £11 per foot?!

Technobots is a more reasonable £12.59 per metre.

http://www.technobotsonline.com/steel-roller-chain-05b-8mm-m.html

That looks like the stuff Farnorth - good spot!

ah brilliant find farnorth! Just as I was about to buy a sproket from HPC as well.......

They're actually pretty good for a whole range of mechanical and electrical components, probably the closest thing to a Greenpower "one stop shop".

We had a very reasonable quote for sprockets and chain, lower than HPC by a mile, from Lakehurst Power Transmission -http://www.lakehurstpt.co.uk/lakehurst_power_transmissions.htm

A second for Lakehurst, we have purchased all our sprockets and chain from them. 3/8 inch chain was £2.19 per meter, Pilot bore (motor end) sprockets were about £2.10 and 50 tooth plate wheel sprockets about £6.50 (all plus VAT).
They are happy to supply just a single plate wheel gear or pilot hole gear at a time and any length of chain (postage is on top though). Also when we were stuck they sent a gear for an early next day delivery for us. On talking to them they are also happy to do modifications such as drilling out the holes etc.
All standard cogs though, nothing a special as BobC's shown above :)

For chain use your local bearing stockist we pay about £5 a meter, they can supply plate wheels up to 91 teeth as well all you need to do is drill holes to lighten them.
A.

Got some chain and a sproket from technobots, all works fine :) Now just to bore out the sproket so it fits on teh motor.....

hi m8 do you still have any sprockets if so will they fit a normal bike chain thanks mike

Yeah, still got a couple. No, these are for 8mm chain, normal bike chain is 1/2 inch (= 12.7mm)

ok thanks please could you tell me who made them for you and did they cost much i need a big chain ring made and i cant find no one to make them thanks m8

Hi WL, they cost a tenner each, they were made by the laser cutters at the end of the street where I work. I took them a correctly scaled dxf drawing & picked up the finished item(s) 2 days later.
I used solidworks to generate the dxf but autocad or various free-off-the-web programs can do it. If you want instructions for drawing a proper chain sprocket tell me your email & I'll send you a short decription, alternatively there are programs on the web that do it, but may not integrate into your drawing package so easily ;^)