Ariel Owners Motorcycle Club

I'll vote for filing off the peaks. My SQ4 clutch was much like that when I assembled it as an Ariel newbie - it was virtually impossible to change gear. Filing off the peaks made it workable for a few months until I found a new clutch basket.

Clutch centre after some attention with a file. Not perfect, but also perhaps not abysmal either? I’m inclined to run it and see how things go:



I have new cork friction and plain plates on the way courtesy of an exceedingly helpful Geoff Brown at Club Spares.

I think I'm right in saying - that clutch centre should have a boss on the inside. (Unless you've got a CP gearbox?)

SG

Interesting… wouldn’t have anticipated that, but it does account for the additional thrust washers that had been used to space out the centre until the centrenut would bite (which it wasn’t doing very satisfactorily).
B****r. Another unobtanium part to get hold of…

Simon.Gardiner wrote: ↑Tue Feb 01, 2022 1:52 pm I think I'm right in saying - that clutch centre should have a boss on the inside. (Unless you've got a CP gearbox?)

SG

When did they introduce the friction material in the back of the basket? 1957? the clutch centre in the picture is not designed for that, and the boss appears in 1948 so it's an early clutch centre.

You don't have clutch lining riveted to the back of your basket Simon, so in respect of that your centre fits your basket but as you have found it won't suit your mainshaft...

Feked (www.feked.com) have some listed but the photo is wrong - there's no boss showing. If they've got the photo wrong you might be in luck - or it's possible they've got more than one mis-described and maybe the Ariel one is what they've got down as a Panther part.

A while back there were some new ones on ebay - they went, I haven't looked to see if they're back.

Also - have you checked with John Budgen? (Someone will have posted his phone number here somewhere - apologies if that's been suggested already on this thread but I've got fed up wading through the BM love-in ).

Here are some photos of a new Club centre from 1980-something - dimensions are:
total depth at outer edge (ie 'over edges') 1.25"
depth of boss: 0.25"
depth of inner (splined) hole: 0.575"

(I've done a bit of rounding on these figures as I suspect there are relatively generous tolerances.)
SG

Am I right in thinking you've had this clutch working, albeit both heavy in action and slipping?

There is another potential issue here which several have already hinted at. A 1954 engine would
have had a drive side mainshaft shorter than a 1957 engine. This later engine got the longer
mainshaft when the primary drive was moved out to make space for the fully enclosed chaincase.
The gearbox also got a longer mainshaft to move the clutch out. The inner chaincase was new
and there was a thicker spacer between the engine sprocket and the main bearing. It is possible
to fit the thicker spacer to a short engine mainshaft but it's a fight and the engine shaft shock aborber
hardly works at all. If you don't use the thicker spacer the primary chain or the clutch or both rub
on the chaincase. It is of course possible that your engine has been fitted with a longer mainshaft.
Someone who knew what they were doing has had a hand in it at some time. I can't remember
off the top of my head what the relevant shaft lengths are but I'm pretty sure that the info is on
the Draganfly website.

There is a lot to be said for your plan to put it together and try it.

Where the boss is in Simon’s Club Spares centre pic, my assembly had a couple of thrust washers stacked up to make up the difference… however, the centre nut wasn’t quite tight (lock tab was stopping it undoing completely), resulting in the whole thing jangling about and the thrust washers getting chewed a bit by the mainshaft. All a bit unsightly and a potentially bad thing waiting to happen…

Having said all that, when I rode the bike, all I noticed was that the clutch was heavy (not slipping, Will), and this probably has more to do with the plate/spring scenario, than the clutch centre imbroglio…

Needs more thought. Thanks for all contributions.

BTW, there seem to be a lot of Simons round here, apologies for not helping the situation!

Not Simon's, but anyone remember this old sketch?

https://youtu.be/FU-tuY0Z7nQ

Ha, Ha.

Hey, just look at the car, wedge shape, Austin Princess, or British Leyland something.

Probably now all been eaten by the tin worm