The last time I raced, I had two good rides in which I was up with the leaders. Because I was using the CR 4 speed box with the high first gear, I could not get a decent start - however it was perfect everywhere else. In my third and final race, I decided to go for it - so I revved the tits off the motor and dropped the clutch. The bike jumped without destroying the gearbox and I was fourth into the first corner. On the second I turned under and passed the three leaders. I was just ahead when the fuel line popped-off. I'd forgotten to tighten the clip. Those other three guys were riding methanol-fuelled 1100cc CB750 Hondas. I still have not raced with the 6 speed box, and I cannot see myself being able to afford to race again.
It was really silly. I have got standard Commando first gears sitting on my shelf. I could easily have fitted one to the 4 speed CR box and lived with the jump between first and second.
I messed around a lot with gearing setup options.
For a 500 Dominator on tight club circuits I finally comprimised on
The Daytona first gear pair which are a bit higher than standard 14 28
The Mk 2 A Mk 3 second gear pair - again a bit higher than the original Commandos and Dommies 18 23
Commando third gear pair 21 20
The Norton close ratio top gear pair. 23 19
A four speed box is never going to be perfect but this gave me a reasonably even spacing between gears matched to the rev drop on the torque graph.
A standard CR box is totally useless on NZ tight club and street racing circuits. By the time you get going in first the rest of the pack is half way round the first lap.
The standard first gear pair is a bit low for solo racing really
Sorry the following is so messy. I have it on a spread sheet but never remember how to post pictures and photo bucket is out these days
This sheet lists all the Norton AMC gearbox gear alternates that I have been able to find. All gear pairs were for sale at either Andover Norton, RGM, Norvil (Emery) and or British Spares in Early 2003.
Latter Dominator, Atlas and early Commando
23 21 18 14
18 20 24 28
Standard RGM Close Ratio
23 21 19 * 17 * No kickstart
19 20 22 * 25
Late Commando MK 11A onward (1974-75)
23 21 * 18 14 * Must be changed as pair
18 20 * 23 28
RGM Close Ratio Pair Alternatives. third second first
22 20 * 20 * Can use kickstart
20 22 * 34
Combinations of Close Ratio and standard gears to Suit NZ Tracks
These are various options I have tried or thought about using the gears I have or are available.
Close Ratio RGM top pair. Rest late Commando M2A on Close Ratio RGM late Commando M2A second RGM kickstart first
Top Third Second First Top Third Second First
Main 23 21 18 14 Main 23 21 18 20
Layshaft 19 20 23 28 Layshaft 19 20 23 34
1 1.15 1.55 2.42 1 1.15 1.55 2.06
% 0.15 0.34 0.57 % 0.15 0.34 0.33
The first set is what I finally used finally in my Dominator race bike
It gives slightly higher first and second and the best steps I could get between standard gears
I used the second set up for a while . It is good but too tall for very fast starts. Good once moving.
It is the same step between first and second as a late Commando.
another option Late Commando with a RGM kickstart CR first gear
Top Third Second First
Main 23 21 18 20
Layshaft 18 20 23 34
1 1.22 1.63 2.17
% 0.22 0.34 0.33
I havnt tried it because I don’t have a standard Norton top gear pair and they are expensive.