Norton Atlas with an offset crank

Didn't Phil Irving write an article on this back in the 50's. A friend who isn't on this forum built one using a Commando engine with Hinze Keglers help.
I have seen it run and he wasn't afraid to take it on long rides either. I remember him riding it up to the rally in Torry Utah from Albuquerque. They also built a 2 finger clutch for an Atlas. It almost didn't need clutch springs. I know I have pictures of the clutch, just not sure where.
Here is a picture of the modified clutch for a pre-Commando clutch.
 

Attachments

  • Norton Atlas with an offset crank
    19 degree clutch.JPG
    272.2 KB · Views: 56
  • Norton Atlas with an offset crank
    19 degree clutch1.JPG
    296.5 KB · Views: 47
Didn't Phil Irving write an article on this back in the 50's. A friend who isn't on this forum built one using a Commando engine with Hinze Keglers help.
I have seen it run and he wasn't afraid to take it on long rides either. I remember him riding it up to the rally in Torry Utah from Albuquerque. They also built a 2 finger clutch for an Atlas. It almost didn't need clutch springs. I know I have pictures of the clutch, just not sure where.
More discussion about it in this thread…

 
Last edited:
Here is one that has an 270/450 90 degree offset crank. Sir Eddy wanted to build the fastest 500cc Norton on the planet and to get there he believed the 270/450 set up was going to give him the advantage to make it happen.
It was his dream and after many years of development we made it a reality.
It started with rephrasing the crank and bolting it back together, at 10,000 RPM the fear was that the crank bolts might say uncle.
He then decided to get a hunk of steel and make a billet, one piece crank, that worry went away...
He rephrased the cam, and sent it off to Web Cam to make it a 270/450 cam, built a cylinder out of a block of aluminum, modified the head and made some hi dome pistons.
His dream came true in 2016, I kinda like the new noise the Rocket makes...



21 minutes into this one you hear the firing order at speed in the distance.




Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
Norton Atlas with an offset crank
 
Here is one that has an 270/450 90 degree offset crank. Sir Eddy wanted to build the fastest 500cc Norton on the planet and to get there he believed the 270/450 set up was going to give him the advantage to make it happen.
It was his dream and after many years of development we made it a reality.
It started with rephrasing the crank and bolting it back together, at 10,000 RPM the fear was that the crank bolts might say uncle.
He then decided to get a hunk of steel and make a billet, one piece crank, that worry went away...
He rephrased the cam, and sent it off to Web Cam to make it a 270/450 cam, built a cylinder out of a block of aluminum, modified the head and made some hi dome pistons.
His dream came true in 2016, I kinda like the new noise the Rocket makes...


View attachment 118788

Thanks for taking the time to post. Very inspirational. 🏆
 
any info on the record nort swingarm?

comes up here

Set two records in the M-PG500 and MPS-PG500 classes in 2016. The video is on the week.
Beat the previous records by over 10MPH.
The swing arm is a shortened and modified RM250…
 

Attachments

  • Norton Atlas with an offset crank
    IMG_0049.jpeg
    189.9 KB · Views: 28
  • Norton Atlas with an offset crank
    IMG_6726.jpeg
    104.8 KB · Views: 29
  • Norton Atlas with an offset crank
    IMG_1640.jpeg
    478.5 KB · Views: 29
All Norton crankshafts are machined, welded, ground, balanced and nitride heat treated for extra strength and wear resistance. A new flywheel replaces the original flywheel. Crankshaft Customers must supply weight of one piston with rings, wrist pin, cir-clips and identify the connecting rods they plan to use (stock or other). The customer is responsible for making sure that each piston weighs the same amount. The drive side journal is offset behind the timing side journal, in the direction of crank rotation, by 90°.


All cranks are lighter then stock so they have less inertial weight for faster acceleration. Norton Atlas and Commando crankshafts are balanced to 50% unless another balance factor is specified by customer. The higher the RPM range where a desired smoothness is required the lower the balance factor number. A racing engine may use a balance factor of 45% for best smoothness above 5000 rpm while a 40% balance factor is used for best smoothness above 6000 rpm.
---------------------


does the above mean running a commando frame with the usual iso clearances?
 
Set two records in the M-PG500 and MPS-PG500 classes in 2016. The video is on the week.
Beat the previous records by over 10MPH.
The swing arm is a shortened and modified RM250…
ended up reading & finding out about the whole thing, for the first time & very recently, even being around here since 2014

was totally blown away by it all, or the 'Siredward' story, that was/is covered from a to z

would you know the year rm250 swingarm used & mod details?

starts ~ pg3

up to 10
 
Last edited:
Back
Top