Clutch 'snatch'

1200 JOTA

1200 JOTA

Senior member
Location
Australia
Delving further into my 1200 triple which has a few clutch issues.

It's a beast in traffic (as most might be) but having sorted the selector mechanism the remaining problem is a dangerous 'snatch' when leaving the lights in first. The clutch seems to slip a little (maybe) and then grab, unsettling the whole bike and very careful feathering of the clutch is needed to pull away. It might do this a few times before you get moving!

The clutch is now dismantled and is being checked out. No significant wear and the plates / springs are within spec. with no glazing and pretty clean. No clutch slip when under load or accelerating. The problem may be present at higher engine temps more so than when cold. Oil is Mobil V-Twin 20-50 (USA)

I'm considering drilling the basket(s) to alleviate heat and get better oil distribution (and try a different oil)

One concern is the amount of backlash present on the lay-shaft which is about 25 degrees. Could this be the source of it setting up a bounce / snatch?

Anyway .... please relate any comments / suggestions.
 
My freshly rebuilt 3C suffers the same issue. New clutch plates. It would seem to be getting better with a few miles.
Will be interesting to have opinions on the issue.

Paul
 
(Not wishing to be a jackass or anything, but ...) What condition are the chains and the cushdrive rubbers in? How old are the latter?
 
cush drive rubbers in clutch and/or rear wheel.
CLEM

why dont current ones last 30 years like the factory ones did, two years and your thinking "its change time"
 
As mentioned, mine has the same symptoms.
Everything apart from the foundry parts is new.
Rods and balls are ok.

A DAM easy clutch has been incriminated by some.

Paul
 
Paul Marx said:
Simple wear but very worn. Turn it over. Maybe due to somebody used to keeping the clutch pulled in when stopped.
Click to expand...
and that's what I did ... the whole shebang back together and will test it later today

The 'wear' is offset and so the clutch was pushing un-evenly ... I'm hoping that's the fix!
 
Paul Marx said:
Simple wear but very worn. Turn it over. Maybe due to somebody used to keeping the clutch pulled in when stopped.
Click to expand...
I'm not sure that's a good idea. It'll just make another indentation in the other side of the bar and weaken it a whole lot more.

Ideally, the pushrod shouldn't rotate against the toggle bar, because all the rotation is supposed to happen at the balls between pushrod sections. But it's a poor design and the pushrod inevitably bores its way into the toggle bar. It's another example of Laverda's rubbish design solutions. Just making it twice as wide would have been better. At least it wouldn't weaken and then collapse like they do when half worn through. What it really needs is a proper little throw-out bearing for the clutch.

The best you can do is to minimise the wear is to make sure you have an adequate number of balls in the pushrod tube between the actuator end and the clutch end, and that they're OK (not worn flat or friction-welded to one or both pushrods. The pushrod should be in two short lengths with a ball between them, and also another ball in the little cup in the cable actuator mechanism.

You can mitigate wear to that toggle bar by not sitting at traffic lights in first gear while holding the clutch lever in. Always change into neutral if you have to wait for any length of time at traffic lights.
 
It takes about 3 decades of abuse to wear through the actuator bar, Cam. Still, good practice to select neutral instead of holding the clutch for any length of time. Actuator design is a bit primitive, yes, but I've seen worse... The Laverda design is actually very similar to the hallowed brit Norton/AMC box of yesteryear, don't hear many complaints from those!

I do find many bars that are slightly worn, but they've never been a concern, I usually just flip them over to an un-used side.

Snatchy clutches can result from worn baskets and hubs, the plates follow the dents all too willingly, much the same as not disengaging properly. Lengthened levers should actually alleviate the issue somewhat by allowing better control, but the tiny rod travel range can be a problem. Worn balls and rods shouldn't have much influence at all, other than have a negative effect on lever geometry.

piet
 
1200 JOTA said:
a good call ... cush rubbers in the clutch are holding shape but I'd say are hardened (with age)
Click to expand...
It's not their shape that matters. it's their suppleness (or rather, their lack of ...)

If it were me, I'd change both sets. For me, it's on the list of 'regular maintenance'/'do it while you're there' items, really.
 
Fitted new clutch cush drive rubbers once in well upwards of 200,000km (no speedo from 110,000km then 20 years of constant riding) to my SF1. Had a bit fo clatter but NEVER affected the clutch action. Never replaced the rubbers in either the SF1 drum or the Kwaka Z1000 disc hub.

Just sayin' ...
 
Hardened or worn cush rubbers can exaggerate clatter from clutch discs on worn hub or basket splines, as well as chain snatch.

Yes Clem, todays' rubbers are a far cry from OE quality. Repro rubbers rarely last more than 5-6 years without developing play. Maybe they're not meant to be actually used... :rolleyes:

piet
 
I've found that making your own rubbers with polyurethane (as per 4wd suspensions etc.) is an improvement over rubber. Lasts a lot longer, is moldable and you can play with strength vs damping.
 
1200 JOTA said:
I've found that making your own rubbers with polyurethane (as per 4wd suspensions etc.) is an improvement over rubber. Lasts a lot longer, is moldable and you can play with strength vs damping.
Click to expand...
I'll look into that once the repros are no longer made. Effort isn't really justifiable as long as a set costs around €40.

Damping action isn't bad at all, they just deteriorate quickly, be it from the pummeling they recieve or some sort of incompatibility with modern oils.

piet
 
I had that same problem without the worn actuator bar, cushes, springs, new plates, etc. Installed a set of Red's Kevlar clutch frictions and the change was remarkable. No grab or slip..nice.
 
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