BSA Owners' Club Forum

The BSA Workshop => Pre War => Topic started by: BEVANC on 21 April, 2017, 04:29:48

Title: OHV Sloper Gearing
Post by: BEVANC on 21 April, 2017, 04:29:48
Hi folks,
Since recently purchasing an S29 3 speed 500 cc ohv Sloper, I have felt that it was working pretty hard at speed. 

The 1930 BSA Instruction book quotes the following gearing for a 4.93 H.P. model: engine shaft 19 tooth; clutch chainwheel 48 tooth; gearbox driving sprocket 19 tooth; rear wheel 42 tooth.

Mine are as specified except that the rear is 46 tooth, so that suggests an obvious way to drop the revs I guess.

I would be interested to know what gearing owners of similar bikes have.

Cheers,
Bevan
Title: Re: OHV Sloper Gearing
Post by: JulianS on 21 April, 2017, 11:27:34
I dont have a Sloper, but below is from the 1929 parts book showing sprocket sizes.

Looks like your gearing is lower than normal sidecar ratios.

Engine sprockets came with 18 - 25 teeth but no alternatives shown for the pther sprockets.
Title: Re: OHV Sloper Gearing
Post by: DEAN SOUTHALL on 21 April, 2017, 13:20:35
Bevan
for solo work you want
Engine 21
Gearbox 19
Rear wheel 42

Changing the engine sprocket may be the eaiest/cheapest option. M20 and A10 4 lobe engine sprockets fit the Sloper and are easily available.

Its ironioc that you need to gear up just as I am trying to gear down!
Title: Re: OHV Sloper Gearing
Post by: BEVANC on 21 April, 2017, 20:45:23
Thanks for the prompt replies Julian and Dean.

Changing both sprockets should make a hell of a difference.  I wonder what on earth the bike had been used for in a past life to have such low gearing - maybe something like what was being done to the poor Panther in this picture.

Cheers,
Bevan