Trying to identify the clutch fitted to my '59 Dominator I contacted Norvil. This is their response:
"From the photographs you sent us in your email, we can confirm that the clutch is indeed a Commando one. We will send you one of our Set Up leaflets, even though this is not one of our kits. The rotor shown in the latter photo needs scrapping because it is the 2006 Series ones that fly apart, because the magnets are not welded to the centre boss. We will send an attachment to you containing the relevant leaflet." Two questions :
1. Who else markets a belt drive kit using a Commando clutch ?
2. The reference to the rotor needing scrapping - is this a known issue ? Can I just replace the rotor or should I replace the sataor as well ?
Yes/No the rotor is certainly likely to come apart eventually, the magnets lift out the centre steel tube starts to come loose inside the alloy. Use it further at your peril. No need to replace the stator unless it has already been touched inside. This will show as polished pole pieces, perhaps burnt encapsulation or even cracked encapsulation.
Adding my own 2P to the issue of cush drive or not. I ran a Commando engine in a Featherbed for over 100K miles. No cush drive. No gearbox issues at all. Rear chain and sprockets had about the same wear issues that you would expect. As has been said here, the MKIII Commando rear wheel 'cush' does not do a lot of 'cushioning' either.
Following this with interest, as I am contemplating a belt drive on my Commando.
I can add comment to the issue with the rotor though. I had one of these explode in a Triton many years ago. Not a Norton engine but it was one of the suspect rotors and the effect is the same..
The result was an instant lock up, much fiercer than an engine seizure! Happily it was met with an instant and instinctive de-clutch and as luck would have it, I was heading down hill for home at the time, so I was able to coast home.
Luckily it was an easy repair with just a rotor swap and no collateral damage, but this is such a potentially violent failure that all sorts of expensive damage and danger to life is possible.
I will be letting Alan inspect my rotor to properly identify it as a safe or otherwise one, before fitting it.
Alan.. does the '2006' number relate to date, or are these all much older? My rotor dates (I think) from about 2000 I think. Are there marks to look for?
I would think that the insurance company for the factory that made/makes the rotors would be all over this like white on rice. If something jams up and throws you down the road, there could be a LARGE liability lawsuit.
The rotors with the magnets retained by the monkey-metal were discontinued in the 1970s. The old NOC Service notes makes reference to them having been replaced by rotors with the magnets welded to the centre. The change to welded rotors came during Commando production - 1974 has been quoted.
Anyone hoping to sue the successors to Lucas on the basis that a forty-five year old rotor has recently failed because it was not fit for the purpose for which it was sold is likely to be on a hiding to nothing.
Lucas upgraded the rotor and did improve it but not by welding it, that was a cover story they made up but not sure why, maybe to stop others knowing a new process.
I had my doubts about welding, as one of the ways to destroy a magnet is with heat. Although I suppose they could be re-magnetised in a magnetron or "Growler", not too sure how the polarities would work out though?
I reckon the magnet segments were made dovetailed or notched in some way to engage permanently in the ally body?