Sunbeam 3-speed gearbox bearings, 1928 onwards

Thanks to Chris Fisher for suggesting suitable quality bearings for the 1928 onwards 3-speed gearbox I’m putting together at the moment. The gearbox will be a CT close ratio type and is for a 1928 Model 6 that has been modified in the deep and distant past to house a hybrid OHV motor. The motor employs 1930/1931 crankcases with 1927 single port head breathed on by Chris Odling to take a new Amal 289. So, the whole bike is a “bitsa” but now goes very well with a 7.5:1 forged Model 90 piston from the sunbeamland shop.

I might point the “Model 69″ up a couple of hill climbs once the gearbox rebuild stops it dropping out of 2nd gear and we fit a 19” rear rim – it will then take a pair of the excellent Avon race compound Speedmaster and GP tyres.

  1. 1 off RHP LJ1-2RSJ
  2. 1 off RHP MJ7/8-2RSJ
  3. 2 off RHP KLNJ3/4J

With the outer bearings being sealed it might be a good idea to consider implementing a small breather hole in the gearbox filler cap.

1928 Sunbeam Model 6 Longstroke up and running

It was great to get an email from Tony Petherick to say that the new forged piston we supplied was working well in his 1928 Longstroke Model 6. It’s lovely to see one of the iconic Sunbeam models retaining its valanced guards and running with leg shields too. In addition to its lighting kit, the bike also features footboards and an enclosed rear chaincase that hasn’t been lost like so many others.

Tony has fitted more sporting cams to the bike and reports that it runs very well after advancing the inlet cam by two teeth from the marked position. Does anyone have any ideas on cam timing using different cams on these bikes? It was a common “dodge” to fit the 60:30 OHV cams to the sidevalve bikes..

If anyone has a spare petrol cap for the bike please get in touch as the one fitted isn’t quite right and Tony would be keen to give a genuine Sunbeam item a new home.