lets go racing

Slow going while waiting on parts, but finding some time to work on ancillaries.

Mounting plate for the Girling caliper that arrived



Also fabbed up the bracket for the front engine mount that the frame spring contacts.

Next job is onto making a set of rearset mounting plates. I've been pouring through information on the various rigging that folks have engineered to control lateral play at the rear of the cradle; there's heim joint linkages, aluminium blocks between the cradle plates (Herb Becker), and I've seen slider puck set ups located near the bottom of the cradle. Some folks I've spoken to suggest trying to control the play at or as close to the source as possible (i.e. the swingarm pivot), so I made up these acetal swingarm end caps which are just slightly larger than the swingarm tube, and a pair of aluminium slider "pucks" threaded onto 3/8 rod with an inset hex head. The rearset plates I'll make up next will extend forward approx 1.75" to cover the area adjacent to the swingarm, that's where the alu pucks will thread in and abut the end caps, nipped up with jam nut on both sides. May end up being a case of pissing in the wind, but we'll see if it works out

I am very old-fashioned. I always prefer a firm connection between the handle bars and the rear tyre contact patch. Manx Nortons used to have Silentbloc bearings in the swing arm. Apparently, if they were replaced with solid brass, the difference could be felt. I do not know what could be done with a Commando frame which might not cause it to crack. Perhaps the cradle could be forced to rotate around the mount underneath the gearbox ?

Trial fitting components with a set of scrap cases, front mount rebuilt with new verniers and with the lower spring bracket installed everything lines up. I spaced the spring bracket based on compressed spring length at approx loaded engine weight, I should have around .125 of adjustment range but we'll see. The RGM vernier kit needed about .015 skimmed off the caps to fit smoothly between the frame tabs, which themselves were in spec

acadian said:

Trial fitting components with a set of scrap cases, front mount rebuilt with new verniers and with the lower spring bracket installed everything lines up. I spaced the spring bracket based on compressed spring length at approx loaded engine weight, I should have around .125 of adjustment range but we'll see. The RGM vernier kit needed about .015 skimmed off the caps to fit smoothly between the frame tabs, which themselves were in spec

View attachment 116395View attachment 116396

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Could you have set that spring cup us with threads and an adjustable bolt at the bottom to fine tune it in a similar manner to the top spring (MkIII) setup? (Where the front mount bolt just slides thru cleanly at rest)

grandpaul said:

Could you have set that spring cup us with threads and an adjustable bolt at the bottom to fine tune it in a similar manner to the top spring (MkIII) setup? (Where the front mount bolt just slides thru cleanly at rest)

Click to expand...

Yup, that's exactly how it's designed

acadian said:

Yup, that's exactly how it's designed
View attachment 116398

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COOL! Couldn't see the adjuster (and, I assume, lock nut) in the first photo...

More progress, got around to mocking up and fabricating the rearset plates







Made up spacers for the plates to ensure that lateral control pucks are parallel with the delrin caps on the swingarm, when threaded down they sit nicely up against the caps.



The tank arrived a few weeks back, and the the rims and spokes earlier this week, so next on to wheel building

Sweet!!! I see you are using the older oil tank. That's the tank I have on my 70 commando. I don't use the late model oil filter which people mount below the cradle. Instead I use a transmission filter that Jim Comstock suggested, which I mounted in my oil return line. I made a bracket that attaches to the bottom bolts of the oil tank and I just double zip tie the filter and a piece of foam rubber to the bracket so it doesn't bounce around and make noise. I also found a pre-bent hose that has all the right turns for where I mounted the filter to get to it and then from it to the oil tank.... It's a good alternative to adding an oil filter with the extra hoses and the fixture under the cradle which your support spring will probably keep you from mounting...

here's the thread with the pictures of where I mounted the magnafine transmission filter in my oil return line.

https://www.accessnorton.com/Norton...nstall-for-a-70-model-central-oil-tank.28202/