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19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 6:33 am
by malc1091
Morning chaps/chapesses. I am having a blonde moment. A simple question, how do I change the front sprocket to our hosts 19 tooth one. Many thanks

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 6:40 am
by malc1091
Whoops just found out. In the technical notes on a 4 speed one. Is it the same for 5 speed model.

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 6:42 am
by Gwilly
Have a look in the technical notes Here..

http://www.hitchcocksmotorcycles.com/pi ... bullet.pdf

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 7:02 am
by papasmurf
Gwilly that looks a seriously major operation just to change a gear box sprocket.

On other bikes I have had to do so it has been a 10 minute job.

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 8:49 am
by Norm
You haven't stated which bike Cast Iron or Electra, both are similar but different with the tools to get the rotor off an Electra,on a taper and needs a puller. The E/S ones have a nut holding the rear of the inner primary to the gearbox and you need a box spanner to fit the 5 speed sprocket nut which is bigger than a 4 speed nut

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 3:09 pm
by PeteF
Papa, it's pretty standard to have to remove the primary drive on most British engines. Well, old school ones anyway.

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 3:58 pm
by malc1091
A job for a winter weekend. Yes I thought it would be a quick job. It was on my old Yamaha YDS7.

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 4:02 pm
by papasmurf
malc1091, it does look a long job, it only took me 20 minutes to remove the final drive from my BMW with no special tools needed.

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 5:16 pm
by Beezabryan
that looks a seriously major operation just to change a gear box sprocket, says papSmirf. Have you tried the same job with a semi-unit BSA A7/10?

19 tooth gearbox sprocket

Posted: Sun Apr 12, 2015 5:43 pm
by papasmurf
Beezabryan, no I haven't but I have taken a the engine out of an Austin 1300, taken it to bits, reground the crank and reassembled the engine and put it back in the car in 12 hours.
(But I did have access to a very fully equipped workshop over night.)