I hear the forums are buzzing with “expert” advice on Commando gear oil. The rumour is that GL5spec 80/90 or 90wt extreme pressure gear oil will damage the bushes in Norton gear boxes. We have been selling BelRay 80/90 GL5 for years to Norton owners and are not aware of any problem so I referred the matter to the most experienced Norton mechanic I know of in the UK.Here’s his reply:“It’s a load of rubbish. I have stripped and rebuilt many hundreds of Sturmey
Archer dolls head, upright, laydown, AMC and both types of lightweight twin
gearboxes and always use 90 or 80/90 oil without ANY problems.”
Norton Roadholder forks are fitted to Domi’s, Singles, Commando’s and also to several 1964 onwards AJS & Matchless models.
This is a very good design and when in good condition give excellent performance. One of the biggest complaints is that they lose damping performance, as evidenced by the “clunk” at full extension.
There are several internal devices on the market to improve the performance of these forks however the damping problem is usually caused by wear in the alloy damper caps (Part No 06-1347). The damper rod passes through this cap and the rod to cap clearance should be .002″ approx. These caps do wear and clearance of .020 – .030″ is common, providing very little restriction to the flow of oil, which controls the dampening.
I have discussed several times the unsuitability of modern oils in classic cars and bikes with their big flat tappets and larger running clearances etc. The problem is mainly due to the lack of zinc in the oil, which for our purposes needs to be at least 1200ppm.
We have now started carrying this engine treatment additive from Hipertech (Part No H100350 for a 350ml bottle). Adding just 35ml to each liter (that’s about 100ml for the average oil change) will bring the zinc level in your regular oil up to at least 1500ppm.
The product’s primary benefit is to reduce friction thereby reducing wear and ensuring long and reliable engine life. It also helps by protecting against viscosity and thermal breakdown, enhances rust protection (important in vehicles which go for long periods without starting) , improving power and compression and lowering oil consumption.
We have dealt with Brituro, who make mufflers for us, for close to 30 years and there is a rumour going around the internet discussion groups that they have closed down. Joe Dallow assures me that this is not the case. They delivered an order of BSA/Triumph “Ray Guns” and other mufflers to us a couple of weeks ago.
On a recent visit to Anthony Curzon, renowned P11 expert, in the UK he generously invited me to ride a couple of his very rare and unusual bikes.
The first is the experimental unified unit construction 650 Norton which never went into production. Housed in a regular AMC duple frame, the bike just feels right – shifts smoothly, few vibes and handles precisely. Unusual motor has camshaft behind the cylinders and the head looks rather like that of an A10. At first glance it reminded me of an overgrown Electra.
The second bike is a 650 G12 motor installed in the “Pluto” oil bearing frame. AMC developed this frame in the 1950’s, a decade before BSA’s Victor MX. The bike went well but I didn’t find the riding position as comfortable as that on the unified twin.
Big “thank you” to Anthony for giving me the opportunity to ride these bikes.
The lubrication requirements of classic motorcycle and car engines are vastly different from those of modern vehicles.
Modern vehicle oils have to comply with the latest API ratings, dealing with matters such as fuel efficiency and extended drain intervals.
Older vehicles have different requirements, with cork and graphite seals and depend on splash and cling and splash lubrication, running with larger clearances. These engines require different oil formulations for which Classic oils have been designed.
For more information go to – https://www.castrol.com/en_gb/united-kingdom/products/cars/classic-oils/classic-engine-oils.html
We will be bringing in from the UK a supply of 20/50 Castrol Classic oil at the end of April. Order Part No CAS20W50XL $18.52 Canadian per liter ($14.08 US at today’s rate of exchange)
Only took 10 years but we now have this hard to find tool back in stock!