Silverstone gearboxes

[Andy Z]

Are the gearboxes fitted to RBS and RCS models as bad as they are made out to be?
Is there any way of improving them, apart from replacement with a cam-barrel 'box?

Many thanks,
Andrew

[druid]

Silverstone gearboxes

Andy,
The later 5 speeder fitted to the RCS isn't too bad especially if Geoff Nunn reconditions it.
The earlier RBS 5 speeder is pretty awful which is why a lot of RBS models were retrofitted with MX 4 speeders.
The biggest problem is that parts are so difficult to get for either box. Nova will do you a 6 speed cluster but it's not cheap.
Druid

[Colin Sparrow]

The cambarrel five-speeder was first fitted to the RDS. it's what you want if you can find one.

Not sure there's any difference between the unit fitted to RBS and RCS.

I believe they both had a five-speed version of the MX1 'box, which was apparently pretty useless.

Cambarrel five-speeders are virtually impossible to find, but an MX2/MX3 "kidney" four speeder works ok on the track.

[Stan Nicholson]

I didn’t think there was much change in the gearboxes between the RBS and RCS.

The RCS I bought many years ago, and that still is awaiting rebuilding, came with a 4 speed cluster in the bike but also with the original 5 speed cluster. After I damaged one of the gears and the flimsy selector fork in my cam barrel box on the RDS at Daytona in the late 80s, when the 3rd gear overrode the dogs, and while waiting for Nova to make a one-off gear for me, I used the RCS box in 4 speed mode as a temporary measure. As far as I remember, it was still a close ratio cluster with a very tall 1st gear and I read that Albion did supply these 4 speed replacements for the early 5 speeds so that is what must be fitted to my RCS.

I guess the MX gears would work but wouldn’t think they would give as close a ratio as the Albion replacement if the bike is going to be raced, but better than a bunch of neutrals.
Stan

[Andy Z]

Thanks for the replies guys, I have a spare close-ratio MX4 'box which I may be able to use. Might be better off looking for an RDS or RES.
Anyone have an Oulton for sale?

[Brian Catt]

There's a "works cam change box" for sale in an ad in OBM just received. Other Siverstone bits as well. 01484 532179 or 07810 766602 W Yorks.

[Andy Z]

There's a "works cam change box" for sale in an ad in OBM just received. Other Siverstone bits as well. 01484 532179 or 07810 766602 W Yorks.

Thanks Brian - it was a 4-speeder and its sold anyway! Not to worry...