Triplex Primary Chains

Go to Andy the Chainman and get his Duplex chain for the Commando, its a high quality IWIS chain developed for Mercedes timing chains and then used for years on Laverda's as a primary chain by Andy before he started to use it on Commandos. You just put it on the 2 inner lines of teeth and the 3rd outer is left unused.

There is enough doubt about reynolds for it to be an issue, even if it was only a problem with counterfeits and not reynolds own quality how do you know what you are getting is genuine. If you need a Triplex of known good quality then I have an NOS Iwis triplex chain surplus as I went duplex to be able to fit my own electric start before I got round to fit it, it was bought in 1988 before the Chinese were making much of anything but Chow Mein. Alternatively give Andy a ring and see what he says about the tensioner.

About 5 years ago my 76 Mk 3 primary drive area developed a knocking noise when blipped from tick over. I called the Corner Garage help line, was asked how many miles were on the clock, I answered 30,000 and the answer came back: 'Primary chain is knackered.'

I ordered a new Renold triplex chain, fitted it and knocking noise gone to this day. I use ATF in my Commando primary case.

Here's to the next 30,000 miles, if I live that long?

I still can't understand why anyone would spend all that cash on a belt kit?

Richard

I've recently purchased and fitted a new primary chain from Andover Norton. It is made by CZ.

Joe Seifert rates this chain as better than Renold.

See http://www.accessnorton.com/primary-chain-t7712.html#p80561

I considered the IWIS duplex but in this case did not want to leave a non-standard fitment for a future owner.

Andy

I don't blame you Richard ,they have a serious troll problem there.

Previously john_holmes wrote:

Go to Andy the Chainman and get his Duplex chain for the Commando, its a high quality IWIS chain developed for Mercedes timing chains and then used for years on Laverda's as a primary chain by Andy before he started to use it on Commandos. You just put it on the 2 inner lines of teeth and the 3rd outer is left unused.

I contacted Andy and asked about Renolds chain, he wasn't very helpful other than stating again that there are better chains and I only need to "look at them" to see ... not sure what I was to see as I'm not a chain man but will take his advice.

Sounds to me that the 'Chainman' isn't getting a big enough discount from Renold? Just my opinion.

When ever I order a new chain from RGM (For a restoration as I don't seem to wear them out) they are always Renold. I doubt Roger would knowingly stock inferior kit.

I'll let you know if my Commando Renold chain fails or starts the knocking within 30,000 miles. Don't hold your breath.

I do not think that the ATF is a good thing for the chain tensioners of triplex, probably the cause of the noise and only 30 000 miles. On my 850 MK3 I was 60 000 miles with triplex and some oil SAE 30 but not motor oil also.

It's interesting that a triplex chain that is probably massively stronger than is needed for this task and running in an oil bath should only last for say 60,000 miles. Whilst it is not the same situation, one rotary owner whose final drive chain also runs in an oil bath reported 180,000 miles. My own IP2 had a perfect chain and that probably had about 50,000 miles on it. I would be tempted to go for the Andy chain duplex option only to reduce the weight of the chain and bring that weight inboard. The clutch with bronze plates is a hell of a mass and we all know that the bending gearbox main shaft is the weak link when the going gets tough. When I had a bronze clutch I removed a serious amount of steel from the inner diameter of the steel plates because it was not doing anything friction wise.

I think the primary tensioner on the rotary is the same as the Mk3 but as you say it doesn't have the power pulses.

I fitted an o ring to the bottom chain tensioner to stop the oil draining down (not my idear I might add).

Boyer of Bromley used Duplex chains in their racing Tridents, reving to 9000 rpm. A Commando is more about Torque.

Peharps also change the plungers after 30 000 miles ?

Mine J changed them is 60 000 miles only

https://andover-norton.co.uk/en/shop-details/16496/p-chain-tensioner-plunger-69-0622-2-per-bike-

All sorts of rumours about Renolds, aren't there?

I had some Renold technical (industrial) catalogues years ago. I remember a few things:

1) they said that people looked at heavy side plates and thought they were looking at a better chain (Andy is reported as saying "you only have to look at them to see"). But side plates neither stretch nor snap - wear takes place in the bushes, and saving weight is the objective to reduce forces on the system. Thick side plates = heavier chain = faster wear everywhere.

2) rolled bushes (i.e. with joints rolled from plates rather than bored from solid bar) are used on some chains. They might not lookas good - but they can be made more accurately so the drive is smoother so they suit some applications

3) I think they pulled out of motorcycle market because it was a) so competitive that they made better money out of Industrial applications, and b) all motorcycle chains are so grossly overloaded and underlubricated that they can never perform as well as customers want them too...

But who really knows the truth? Most products become worse with time when the customers select entirely by price.