thwaites cirrus nimbus

[aej.Williams]

my thwaites cirrus numbus urgently needs replacement drive sprockets , a 54 page workshop manual shows them, but not their specification...esp the shaft and key slot sizes.
anyone got any ideas where i can get this info ? seems to me that if i have this information it doesn't matter if the other specifications are slightly different as long as they do no upset gearing and match the chain....but shaft must match !!!

any pointers welcome !

[Tillywolves]

Contact David Cornwallis.

http://www.davidcornwallis.com/

[essexpete]

I think you would need a new chain as well if changing the sprockets.

[aej.Williams]

thanks tillywolves and essexpte....i am trying cornwallis but no joy yet....as to chain...that at least will be easy.

as i have the spline data from the petter that end will be no problem...its the thwaites sprocket that is a head scratcher...still it will force me to remove the brake drum clutch and might as well refurb that while i am at it

[Tillywolves]

Alan, make sure you post some pictures of your project. I have a Nimbus as well, although the rear closure plate for the engine is different.

[essexpete]

https://uk.brammer.biz/

I wonder if a company like this could help?

[aej.Williams]

cornwallis couldnt help and dont think brammer cover...but...am doing some welding work at present and will get access to the spindles for picture purposes and at least be able to do some measurements. as is still going and i have work i need doing now,am reluctant to dismantle for moment, but in abscence of any specifications for the larger spindle, will waity til can strip

[aej.Williams]