Ariel Owners Motorcycle Club

Here's the outermost shim, which you will find under the clutch centre:


The shims we are talking about are items 77 and 79:


Here's the chain wheel bearing with the inner shim in place:

Having watched your video, I can see that the nut appears to be jammed on the thread, and is not fully tightened. See picture.
The end float of the shaft should be minimal. Mine is 1/16 inch. The nut will have to come off to investigate.

The correct nut has a recess to allow it run all the way the the end of the thread on the mainshaft, unless your nut has been modified it won't have that. If in doubt by the correct parts from the club or Draganfly!

Thanks for that Roger. I've just removed my nut and found no recess; which explains my slightly excessive 1/16 inch end float.
Now where is my lathe. Cheers Chris.

Chris Sealy wrote: Sat Mar 28, 2026 12:51 pm Thanks for that Roger. I've just removed my nut and found no recess; which explains my slightly excessive 1/16 inch end float.
Now where is my lathe. Cheers Chris.

Where would we be without our lathes!

Should be just the first 2 threads bored out to the nominal diameter of the thread, Although what Simes has done would work, however I would make the recess with a smaller OD.

Here is mine after fettling. When I refitted it,I found that the gears were very stiff to turn and there was no end float. It took a while to realise that the inner end of the ratchet spring had somehow become lodged between the ratchet pinion bush and the ball bearings inner race.
All sorted now, with Loctite, and a much better 1/32 inch end float. Sadly I'd already done it before I saw Rogers last post.

Hi Alan. I just reviewed the pictures of your clutch. I notice that the tab washer on the clutch centre nut is fitted back to front. The tab should be at the bottom of the stud, otherwise it can interfere with the spring cup when the clutch is engaged.
Cheers, Chris.

Thanks Chris, I'll take note when re-assembling. I stripped down further and have found a few other 'interesting' features that I will remedy when putting it back together. Finger tight bolts holding the clutch on with no locking tabs. Primary chain joining link running backwards (no issue as it had stayed on).

But a few more questions first.... I have attached another short video of play on the sprocket roller bearing. Does this look excessive? If so, what is the fix? New roller bearing carrier and rollers?

You will see on the video wear marks where the sprocket has been rubbing the primary case - see also the picture of the case here: I think if I take out the float on the shaft, things will be well - but if I need to change the bearing, so be it. Advice please.....

The shims we thought were missing are both in fact there - I think the fault was, as someone pointed out above, the end nut on the kick start side was not under cut. I now have the correct nut, but the end of the shaft is damaged (not badly, just wrong threaded nut forced on) and the correct nut will not pick up the threads straight. So I need to cut the threads again - can someone advise what thread cutter I need? Assuming 1/2 inch Whitworth, but maybe not....?

Now going away for the weekend - so won't get back on it until next week. Thanks for everyone's input. Much appreciated.

The mainshaft thread is certainly a whitworth form, but measure the OD and the TPI. It will be CEI, but right now I can't remember the size.

I'd speak to club gearbox spares - a good mainshaft might be available.

On that bearing, yes, I think it looks a bit wobbly - but remember it only moves when the clutch is disengaged.