Chains, my babys got me tied up in chains

If modern Renold / Reynold is rubbish, has someone told them?

What is the link contacting ? I have an Iwis (20.9mm across the spring link) - on a Mk3 admittedly but it certainly doesn't catch.

Hello Alec

Not that i want to spoil anyones fun but i wonder why anyone now should be fitting what is essentially a race cam to anything that is not a race motor. The PW3 has got higher lift than the standard cam therefore giving the valve gear a harder time. Fitting a PW3 will not give anymore performance, unless the whole motor (especially the cylinderhead) is optimised. The only thing that will improve (if just the cam is changed) is the noise!

The popularity of the PW3 cam is because it has been pushed as being the 'best cam' by the two 'norton specialists' responsible for getting a batch of them made. I know this because i fell for that same line. Asking one of them 'What is the best cam to fit in my commando?' A PW3 was the answer....This cam lasted all of 1500 miles before two lobes had worn off.. I sent it back to the supplier who sent it to the manufacturer and i got the cam and a reply back saying it was fitted incorrectly possibly coilbinding.

I made a rig to check the amount of free lift at valves fully open and they were not coil bound.

I have now got a standard cam fitted in my engine and talking to a couple of commando owners these two 'specialists' have been pushing these unsuitable cams onto unsuspecting owners that do not need them. In one instance fitting a PW3 into a customers engine without telling the owner what it was. In fact he (the owner) didn't know what a PW3 was until i told him! That engine has a single mikuni carb fitted, so negating any so called improvement anyway!

I did think to start this tale with the question 'Are you going to ride everywhere at WOT because that is what this cam was developed for, Racing!

Regards

Peter

Times change and the PW3 has been re-made now for about twenty-five years. Back at that time, many of us were still chasing the performance route on Commandos and there was certainly a demand for it.

If built into a motor with a bit of head work, it is quick and with more low-down power than the alternatives commonly available at that time (the 2S or 4S generally)

The downside, as you've mentioned is noise. Even with standard silencers, the thing gives a loud bark that is unpleasant to ride behind and borderline anti-social in built up areas.

I'm sure that there will always be people who want maximum acceleration from a bike that feels like a Commando so there will probably always be a market for them but I wouldn't bother anymore.

My tuned PW3 750 has gone and the standardish 850 Mk3 is still here.

I am exceedingly boring and unadventurous and still stick with Renold 3/8" x 5/8" chains. They generally last about 6,000 miles, except in my B31 with a fully enclosed chaincase where they just go on and on and on.

It's road much and especially salt that kills chains.

There is not much clearance with the back of the chain case and if the casting is bent due to the centre bolt spacers being missed out then it will be even less. This is normally indicated by cracking at the front of the chain case forward of the alternator. If you want to fit a Gucci chain then consider having your rear sprocket skimmed down to suit a 520 O ring chain and fit a Dommie gearbox sprocket. If you are lucky enough to have an early bolt up rear wheel then the Dommie rear drum/sprocket will fit straight on (though the sleeve nuts have a cycle thread as opposed to the Commando UNF thread, Commando sleeve nuts are identified by a little groove turned into the outer diameter)

I did consider going back to my 47 year old standard cam from a PW3 but there is too much work involved and it goes quite nicely

The chain link thing is so simple to rectify. Turn the bloody thing around! Put the split link on the right/inside nearest the wheel. Too simple yet it has worked for me for the last fourty years.