Wanted - sidecar sprocket for A10 FWH

[RDfella]

Project's gearing is way too high (or low in engineering terms) so I'm looking to replace the 42t rear wheel sprocket with a 49t (A10 swingarm FWH). UK only, otherwise postage will be a killer.
Thanks

[RoyC]

Project's gearing is way too high (or low in engineering terms) so I'm looking to replace the 42t rear wheel sprocket with a 49t (A10 swingarm FWH). UK only, otherwise postage will be a killer.
Thanks

I changed the engine sprocket.

[RDfella]

If only it were that easy, Roy. I have an 18t gearbox sprocket, but 1st gear is where 2nd should be - rather like a close ratio box. The primary ratio was deliberate, to reduce torque on the gearbox - also governed to some degree by belt availability. Not a wide range of lengths for the polychain series.

[chaterlea25]

HI RD,
I have never seen a variation on the std 42t late type rear sprocket ?
Time for some home brew sprocket re toothing ????
I am sure everyone would love to see and hear more on the Special's progress on another topic

John

[JulianS]

The only factory variation I can see listed was for a 43 tooth iron FWH sprocket for the sidecar A50 part 68 6034.

[Greybeard]

If only it were that easy, Roy. I have an 18t gearbox sprocket, but 1st gear is where 2nd should be - rather like a close ratio box. The primary ratio was deliberate, to reduce torque on the gearbox - also governed to some degree by belt availability. Not a wide range of lengths for the polychain series.

I'm flattered that you bothered to add my short version forum handle to the casting!

I'd also like to see a lot more of this beasty.

[RDfella]

Hi all, thanks for the replies. The bike is is completed and at last registered, save for the electric starter I'm in the process of devising. Will post some final pics and a vid - when I can persuade my son to take them - and presuming I can upload the vid.
Re the sprocket - I see the rigid / plunger have a 49t option. Was hoping the swing arm had one also, but it appears not. Have to weld a few more teeth on it seems. Was trying to avoid destroying a good 42t sprocket.

[chaterlea25]

Hi RD,
I am sure one of the members on here will have a worn sprocket thrown in a corner that they would be willing to send you 

John

[berger]

RD is yours a back brake and sprocket combined? I have one that was turned down thinner for a 1/4 drive chain for racing that is waiting to get jumbled. just read back yours is FWH so no good, and it says so on the heading, ignore me still sleep deprived because of the itchy burny rash

[Swarfcut]

RD  Any chance of something from the Trials/Speedway/Grass Track community? Years ago the weeklies carried ads from a maker of custom sprockets, I have a recollection it was in Wales. Ring a bell for anyone?

 Swarfy.

[Greybeard]

.... still sleep deprived because of the itchy bum rash

 

[berger]

what ya like GB

[RDfella]

Hi folks,

currently looking at a range of aftermarket sprockets (for kwaka etc) with the correct 530 tooth profile. Trouble is most are 'well ventilated' and I need to ensure there's enough metal below the teeth to actually reach the old hub. Another criteria is that it needs to be steel - don't plan trying to weld an alloy sprocket to a steel hub. My alloy welding is bad enough as it is, but many advertisers don't specify what their sprockets are made of. Normally I'd buy a pilot bored simplex sprocket and machine it to fit, but it seems suppliers of those have become a trifle greedy with prices around £100. Do they cut the teeth by hand these days?

[Simon59]

Hi RD

I have a 49 teeth rear sprocket left over from my A10 plunger rebuild. It was a sidecar sprocket so, I replaced it with a 42t new one as I ride solo. It's a bit worn and it's plunger rather than swinging arm, but it's yours if you want it for just the postage costs.

Cheers Simon

[KiwiGF]

Hi folks,

currently looking at a range of aftermarket sprockets (for kwaka etc) with the correct 530 tooth profile. Trouble is most are 'well ventilated' and I need to ensure there's enough metal below the teeth to actually reach the old hub. Another criteria is that it needs to be steel - don't plan trying to weld an alloy sprocket to a steel hub. My alloy welding is bad enough as it is, but many advertisers don't specify what their sprockets are made of. Normally I'd buy a pilot bored simplex sprocket and machine it to fit, but it seems suppliers of those have become a trifle greedy with prices around £100. Do they cut the teeth by hand these days?

In Nz (which does not help you) blank sprockets are available and not expensive, last time i bought one was to get it machined then welded onto a b31 hub. Maybe that brand is available in uk? They seem to be made in very hard steel.

http://www.cycletreads.co.nz/resources/6422-37.pdf

http://www.cycletreads.co.nz/products/1447-chiaravalli_sprocketschainwhee/6422-chiaravalli_carat_sprockets_fr.aspx