Clearances

The NRE 750 motor has some unusual spacing dimensions, so careful alignment is in order.  Shims and custom spacers are used to get everything in its proper place.  It all starts with getting the motor and gearbox aligned in the chassis.  Then, the clutch must align with the crank pulley.  Spacer there, moving it outboard a bit for true belt run.  Then onto gearbox-to-rear sprocket alignment.

 

A very handy laser alignment tool aids in locating the rear hub to its proper place for a perfect chain-run to the countershaft sprocket.  Easy and accurate, but after all this, chain-to-tire clearance can be an issue, especially when running 130mm-width tires.

 

We had the clearance necessary without much ado.  If not, the next solution would have been to move the countershaft sprocket outboard, or perhaps an even more radical solution; moving the drive-side engine plate outboard by spacing between the motor and drive side plate, while keeping the gearbox flush to the DS plate, but spacing equal amounts between the gearbox and timing side plate.
We’ve done it before, but again, it was not necessary in this build.  Fortunately.

 

After a full day of alignment tasks, the big payoff – a rolling start to a badass fast Seeley NRE racing bike, the likes rarely see here in the U.S.

 

Master NYC Norton technician Jon Thorndike tidies up after a good day of alignment work.

See all posts on this build by clicking here: https://nycnorton.com//tag/nre/

 

2012-04-11T15:55:10+00:00March 3rd, 2012|builds, nycNorton, racing|