What Did You Do With Your Commando Today?

I decided to swap out my antique clutch plates for Bennett’s , I guess I ordered the wrong kit as I only had 4 plates instead of five so I stuck in one bronze. Tranny shifts like a new bike, clutch is really easy to operate. Wish I had done it years ago. I also added a second spring to my Mikuni slide to fix a sticky slide.
 
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What did I do with my Norton Mk III today? Wiped up huge oil slick from under it, anti wet sump valve must be stuck!!! Better open then closed! LOL
 
Pulled the 6 V. Lucas coils and fitted the new Tri-Spark 6 V. coils on the street in plus 4 C. Put battery back in and she fired up first touch of the magic button. Full choke and tickled. Tri- Spark says they are better with a longer duration spark. Anyone know if true ?
Sales sheet says longer duration and a stronger spark and operate cooler than the Lucas equivalent.
 
Yep connect that throttle to a single VM mikuni and you sure get a good rev limiter or to be more accurate a performance limiter no matter how much you twist it
Yep that’s another rev limiter, but not factory.
 
Changed my fork oil. Just a few drops from the drain hole. Thought I'd pump the forks to see if there was any trapped. Spent the next hour cleaning up my bike mat.

Live and learn!
And what oil did you decide on in the end ?
 
Fuchs Silkolene SAE20 fork oil. Mail order (Hitchcocks). I can get 15w locally, if it's too harsh.

Going to have to find a better way to lift the bike. My current bike jack needs to go under both frame rails and won't go past the centre and the sidestand. Ended up raising it with a trolley jack under the front cross rail, with the centrestand down, but didn't feel very secure.

Needed doing. The old oil looked like gravy.
 
Fuchs Silkolene SAE20 fork oil. Mail order (Hitchcocks). I can get 15w locally, if it's too harsh.

Silkolene SAE 20 should be ok. I used that before I fitted the Lansdowne dampers.
Although 10W/30 etc. is listed in the lubrication section of the workshop manual, it does say SAE 20 in section G8.
 
SAE is used as a standardized motor oil grading system. Thus, a 20w in one brand of oil has similar viscosity characteristics to another.

There is no standardized system for fork.oils. One brands 10w may be similar to another's 20w and yet anothers 7.5w.

This is a good read and has comparison tests of a great many fork oils by brand and weight. Comstock-worthy work.

 
Fuchs Silkolene SAE20 fork oil. Mail order (Hitchcocks). I can get 15w locally, if it's too harsh.

Going to have to find a better way to lift the bike. My current bike jack needs to go under both frame rails and won't go past the centre and the sidestand. Ended up raising it with a trolley jack under the front cross rail, with the centrestand down, but didn't feel very secure.

Needed doing. The old oil looked like gravy.
Note that Fuchs Silkolene is SF20 not SAE.

What Did You Do With Your Commando Today?
 
I think that is mislabeled on the shop site.

Silkolene fork oils don't appear to be SAE rated.

View attachment 83877 .
SF20 still appears to be an 'SAE 20' viscosity fork oil.

"Description:​

Silkolene SF 20 Monograde Fork & Suspension Fluid​

Silkolene SF 20 is a monograde SAE 20 fork and suspension fluid featuring a high VI index formulation. It combats friction, protects seals, resists corrosion and ensures smooth suspension under all road and competition conditions. Grades can be mixed.

Silkolene's SF range are based on highly refined base oils and advance performance additives to provide optimum damping and consistent smooth fork action for road going machines and those requiring heavier base oils."
 
SF20 still appears to be an 'SAE 20' viscosity fork oil.

"Description:​

Silkolene SF 20 Monograde Fork & Suspension Fluid​

Silkolene SF 20 is a monograde SAE 20 fork and suspension fluid featuring a high VI index formulation. It combats friction, protects seals, resists corrosion and ensures smooth suspension under all road and competition conditions. Grades can be mixed.

Silkolene's SF range are based on highly refined base oils and advance performance additives to provide optimum damping and consistent smooth fork action for road going machines and those requiring heavier base oils."
This is from a web store.

The screenshot I posted above was from the manufacturers catalog and.they don't mention it anywhere being SAE 20.


ISO 68 correlates with SAE 20, but it isn't SAE20

QUESTION FOUR: IS FORK OIL MEASURED BY THE SAE SCALE?

No. Fork oil weights are derived from the industrial standards used for hydraulic applications, called the Saybolt Seconds Universal (SSU). This measurement uses a similar viscometer arrangement as used to determine a cSt value, but grades the oil using a much more sensitive viscosity calibration scale.

QUESTION SEVEN: WHY DOES MY FORK OIL HAVE A WEIGHT?

Consumers like to shop for oil by weight. So, the motorcycle industry took the SSU/VI measurement and converted it to weights based on the same scale used by the SAE. But since the SAE weight schedule is so widely incremented, two cans of fork oil with different SSU viscosities of 80 and 100 can both be listed as a 5 weight (5wt). Yes, it is confusing!


I know that I am being pedantic.
 
This is a good post by Ken.

 
ISO 68 correlates with SAE 20, but it isn't SAE20


If Silkolene SF20 is not the approximate equivalent to the previous Silkolene 'SAE 20' fork oil (the containers are marked SAExx) then the question should be "What is?".
 
It feels the equivalent. Took it for a long ride and am happy with the forks. Happy to recommend it for spirited back road riding. No chatter and holds the line of bends happily.
 
Happy new year fellow Norton enthusiasts!
I'm sold on this Fuchs 20. I'd like to try it. Any idea where you can get this stuff here in the USA?
 
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