Engine offset ???

[marshg246]

Does anyone have width measurements of the various vernier adjusters and abutments ?

Pretty sure AN does. technical@andover-norton.co.uk or just call them since you are in the UK.

 

[L.A.B.]

The only spare one I have to measure is the Mk3 rear abutment which is .895"/22.73mm.

 

[Andy Higham]

Thank you

 

[Andy Higham]

Without removing the rear ISO, a rough measurement of what I have at the moment using steel rule

Left rear adjuster approx 24mm
Right rear Abutment 28mm

Measured in my hand with digi caliper

Right front adjuster 19.97mm
Left front abutment 19.9mm

 

[Andy Higham]

I put the front ISO back in and removed the head steady completely, the head shifted to the right.
So my engine was tilted 1/8" to the left at the cylinder head
Now with the existing ISO set up and no head steady, the engine is straight in the frame but on the centreline. The rear wheel looks reasonable central in the loop.
When I get the adjusters/abutments from RGM I can work out what has happened.

I am in the process of designing a link type head steady, this should have the adjustability to align the head left/right accurately

 

[L.A.B.]

Left rear adjuster approx 24mm

Right front adjuster 19.97mm

I don't understand that as both front and rear Mk3 adjusters are the same part. The pre-Mk3 conversion kit front adjuster is thinner but I don't know the size.

 

[hybridracer]

When I wrote about the Commando drum braked back wheel rim offset in a technical letter in “Roadholder” many many years ago, I never expected discussions about wheel and engine offsets to spread and continue for ever.
The offset was 3/16” on the first Commando, not 1/8”, and I don’t believe that it was ever changed by Norton.
Sorry if this is a bit blunt but that is me.

 

[L.A.B.]

The offset was 3/16” on the first Commando, not 1/8”, and I don’t believe that it was ever changed by Norton.

I originally thought the offset was closer to 3/16" but the offset of the head steady and swinging arm seemed to make it closer to 1/8" and Vernon Fueston's measurements so I'm not going to argue about 1/16".

 

[Andy Higham]

I just assembled the RGM stainless caps, abutment, and adjuster onto the front ISO along with the old nylon washers.
End of assembly outside of mounting plate on RHS (adjuster) is 32mm
End of assembly outside of mounting plate on LHS (abutment) is 26mm

That should be about 6mm engine offset to the left. About 1mm more than 3/16