BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Fereday on 26 March, 2017, 21:21:30

Title: Speedometer
Post by: Fereday on 26 March, 2017, 21:21:30
Just took the bike out for first time and noticed the speedo bouncing allover the place could the wrong drive be on the bikes a 1965 thunderbolt.
Title: Re: Speedometer
Post by: JulianS on 27 March, 2017, 09:31:18
Check condition of cable, even if new, disconnect from speedo head and observe cable end as you revolve the rear wheel by hand. It should spin true and not wobble from side to side too much. Check cable properly engages at bothe ends. Make sure cable not crushed and does not have very tight bends. Check condition of inner by withdrawing it. Often speedo problems are cable problems.

The actual drive from gearbox is quite robust but could be damaged. Only way is to check the teeth.

Could easily be the speedo.
Title: Re: Speedometer
Post by: Fereday on 27 March, 2017, 15:19:41
Have checked cable seems OK but the speedo drive on wheel stop's and starts and makes a clicking sound when it stops winding then OK when working again.
Title: Re: Speedometer
Post by: JulianS on 27 March, 2017, 16:14:31
Sounds like the worm is worn.
Title: Re: Speedometer
Post by: Fereday on 27 March, 2017, 17:44:30
Trouble is it's brand new ah well looks like a new one again
Title: Re: Speedometer
Post by: JulianS on 27 March, 2017, 18:41:46
You say the bike is 1965 - is it a 1966 season job, A50C frame, from autumn 1965 with rear wheel speedo drive, or is it a 1965 season job with gearbox driven speedo?
Title: Re: Speedometer
Post by: Fereday on 27 March, 2017, 20:19:52
A50c frame in rear wheel