C: Clutch Grossett Starter and Clutch Slip

[Leonc]

My 1950 C Rapide has had an annoying habit ever since I installed the electric starter a couple of years ago.
I use the correct technique of spinning the engine over on the decompressor and then releasing, but often the clutch does not bite well and I get some slippage causing the engine to not spin very effectively.
I will eventually get it to start, but it is not a good quick start and will take multiple attempt to get it turning over well.
The clutch behaves well on the road with no slip issues, and I have been through it several times and it has good near new components, well adjusted and seemingly normal.
Has anyone else experienced this and had a fix?

Two part question, if I was to replace the clutch with a modern unit, who has had real life experience with the Burtons Bike bits V2 or the Vincent Spares C1/V units?
Do they overcome all issues and worth investment?
TIA Leon

 

[Mike T]

Hi Leon, I don't know if this is similar and will help or not but my friend Geoff has the Grosset starter and also the great V3 clutch on his Rapide. His clutch started to slip a little recently. He bought some stronger springs and only fitted two of them and it fixed the slipping immediately. He seems really happy with it. Good luck!
Mike

 

[CarlHungness]

After reading about Vincent clutches for a couple of decades and then listening to journeyman Roy Cross (who installed at least 2-3 other brand
replacement clutches) he has said if he had to do it all over again he'd sure
stick with the stock clutch. There's adjustment and more adjustment. Roy has
published plans for a jig to set up the unit and I believe they are on this forum somewhere. Journeyman Vincent man Glen Bewley copied the plans I recall, and so did I, so I'll search my computer to see if I can find them.

 

[CarlHungness]

My 1950 C Rapide has had an annoying habit ever since I installed the electric starter a couple of years ago.
I use the correct technique of spinning the engine over on the decompressor and then releasing, but often the clutch does not bite well and I get some slippage causing the engine to not spin very effectively.
I will eventually get it to start, but it is not a good quick start and will take multiple attempt to get it turning over well.
The clutch behaves well on the road with no slip issues, and I have been through it several times and it has good near new components, well adjusted and seemingly normal.
Has anyone else experienced this and had a fix?

Two part question, if I was to replace the clutch with a modern unit, who has had real life experience with the Burtons Bike bits V2 or the Vincent Spares C1/V units?
Do they overcome all issues and worth investment?
TIA Leon

This is not the drawing of the Roy Cross jig, which I cannot locate, but it's
a pretty good verbal description of the unit itself.

 

[Robert Watson]

Also remember that when starting a twin the shorter lining on the shoes are engaging with the drum and on driving the longer linings do the work, that may be a good place to start!

 

[Leonc]

After reading about Vincent clutches for a couple of decades and then listening to journeyman Roy Cross (who installed at least 2-3 other brand
replacement clutches) he has said if he had to do it all over again he'd sure
stick with the stock clutch. There's adjustment and more adjustment. Roy has
published plans for a jig to set up the unit and I believe they are on this forum somewhere. Journeyman Vincent man Glen Bewley copied the plans I recall, and so did I, so I'll search my computer to see if I can find them.

Thanks, those will definitely be of interest.

 

[greg brillus]

Remove the clutch cover and observe the clutch assembly whilst it is turning over to see if it is in fact the clutch slipping........it is not uncommon for the starter sprag clutch to slip as well........if it is the later, then that is a different story.

 

[Leonc]

Remove the clutch cover and observe the clutch assembly whilst it is turning over to see if it is in fact the clutch slipping........it is not uncommon for the starter sprag clutch to slip as well........if it is the later, then that is a different story.

Yes, I have observed the clutch slipping with the cover removed when using the starter.

 

[vibrac]

There is a lot of immediate Tourque necessary to get those flywheels moving the decompressor helps but its mainly just the inertia of the engine to overcome. I guess the comet inerta is lower but the chain driven starter seems to cope without the decompressor in the head (I omitted to fit ) never the less when I get a chance I will fit another spark plug hole

 

[robert shennan]

I had this very same issue with my Rapide which had a wet V3 clutch fitted and starter, The clutch tended to slip on first start up then was OK after that. I experimented with stronger clutch springs but could not find a happy medium between getting the bike to start easily and then run without the clutch dragging when the engine warmed up. I contacted to Neal Videan who recommended changing over to a dry V3 clutch which seems to have solved the issue. As a side note I also changed over to a lithium battery after chatting to Conways, touch wood all good now.