The Marston Sunbeam Club & Register Forum

General Category => Technical Discussion Forum => Topic started by: oggers on April 26, 2023, 11:13:47 AM

Title: Clutch stops
Post by: oggers on April 26, 2023, 11:13:47 AM
Gents

1931 Model 9 has two clutch "stops" on the chaincase which allegedly ease changing gear and stop the clutch rotating when the lever is pulled in - especially from neutral. Has anyone any information as to how to set these up please?

Many thanks

Title: Re: Clutch stops
Post by: phutton on April 26, 2023, 01:08:50 PM
There is a good description in the 1931 manual. Essential reading if you have a 1931 machine!

I use a slightly different method: pull the clutch right in and lash the lever to the bar. Turn the stops in until they just touch (worth using a feeler gauge). Release the lever, and screw the stops in 1/2 to 3/4 of a turn each. This gives you most of the lift available, but still acts to stop the rotation. You can check the has stopped through the aperture in the c/case with the engine running.
Title: Re: Clutch stops
Post by: oggers on April 26, 2023, 02:52:31 PM
Thanks Paul. That makes sense. Does it work? I have not seen such stops on other bikes and I have occasional trouble in selecting 1st from standstill.
Title: Re: Clutch stops
Post by: phutton on April 28, 2023, 10:29:26 AM
If you get the set-up correct then the stops do work - until they wear! The just re-adjust.

P.
Title: Re: Clutch stops
Post by: Rick Parkington on May 01, 2023, 03:57:52 PM
Just to add my six pennorth to this topic.
When adjusting my clutch stops once, I realised two things. First that the stops can only work when changing into gear from neutral while stationary. This is because the pressure plate is permanently attached to the gearbox mainshaft, via the clutch centre and spring holder studs. When the bike is moving in gear, regardless of what you do with the clutch, the mainshaft is attached to the rear wheel and turning with it. Obviously the clutch stops can't stop the bike rolling so it's important they cannot contact when riding, or they will just wear rapidly every time you pull the clutch to change gear. 
To avoid this, I adjust them so they contact only with the clutch lever pulled fully in to the bar, because you don't pull it that far when just changing gear.   
But personally I adjust them back so they don't contact at all. So long as the clutch is adjusted correctly, if you free the plates with the kickstart, or blip the throttle with the clutch withdrawn to snatch it free, you won't need them anyway.
Cheers Rick 
Title: Re: Clutch stops
Post by: oggers on May 02, 2023, 11:52:31 AM
Rick

You would surely only want the stops to work from neutral anyways. Far easier to change gear when on the move and yes, perhaps clutch stops are thus not required when moving. I have adjusted according to Paul and things seem to have improved. I have yet to give it good ride. Only completed the full resto yesterday. Pics soon....
Title: Re: Clutch stops
Post by: hennie.nijhuis on July 04, 2023, 02:57:01 PM
Hello Oggers;

I comply with the solution that Rick P mentioned.

I adjusted the stops so they would stop the clutch, but on the move te gear changing, Up and Down, made a lot more noise :)

So I adusted the stop as Rick mentioned, they have no funtion anymore, and now with a slight blip the downward shifts produce a lot less noise.

Greetings, Hennie