classic motorcycle forum

Motorcycle Discussions => British Bikes => Topic started by: RODEO on February 21, 2009, 11:31:00 AM

Title: Albion Gearbox .........Unusual project!
Post by: RODEO on February 21, 2009, 11:31:00 AM: Hi All
   Im a newbie,and need some info please!...........
  I have an ALBION 3 spd gearbox. This make Im told was fitted to several vintage models over the years. It has a 14 tooth input sprocket ,and a 42 tooth output ,on the dry clutch.And has a built in kick start.
   Does anyone know what size sprockets were fitted to the rear wheel ,and the engine respectively on any bike with this gearbox?
  I want to use it on a 3 wheel vehicle,with the single rear wheel driving.Ihave an 8hp Briggs and Stratton engine to power it .
  I was thinking maybe starting with a 42 tooth on the rear wheel ,and a 14 on the engine?? Due to the cost of sprockets ,I dont want to have to try many ,unless I can help it ,so I need to start somewhere near the mark.Any help appreciated!
   Thanx Rod
Title: Re: Albion Gearbox .........Unusual project!
Post by: geoffus on February 22, 2009, 03:17:16 AM: :) I think maybe it should be 42 input 14 output best of luck with your project geoffus
Title: Re: Albion Gearbox .........Unusual project!
Post by: RODEO on February 22, 2009, 12:58:36 PM: Yes ,youre right! Realised it after I posted!
Title: Re: Albion Gearbox .........Unusual project!
Post by: andychain on February 25, 2009, 08:42:24 PM: Depending on chain size buy a platewheel and get it machined ask any bearing stockists.

Nametab in Redditch are good for supplying and machining such sprockets.

Andy
Title: Re: Albion Gearbox .........Unusual project!
Post by: cardan on February 25, 2009, 09:07:13 PM: Hi Rod,
To give you some idea, an 8 h.p. (say 1000cc sidevalve twin) motor in an early motorcycle would be geared at around 4:1 (4 turns of the engine for one of the back wheel) in top gear with wheels of rolling diameter 26".
Your proposed 14/42/14/42 gearing would give an overall ratio of 9:1 in top gear (1:1 in the gearbox), so it would be very low geared. But then you have to carry around 3 wheels, and the B&S might turn higher revs than an old twin. Some experimenting will be required!
Leon