Isolastic Question

I'm getting ready to put my '69 "S" back together with MKIII vernier isolastics. Is there any reason not to install the isolastics backwards? If not adjusting the rear on the right side would be quite nice. I don't see a reason not to reverse it. Is there a reason that the adjusting side is reversed front to rear?

Nelson

I wondered about that when I did mine. I figured there must be a reason, so I followed instructions. Only want to do that assembly once (especially the rear). Adjusting from the left side is no big deal.

With the high pipes on the "S" model it would be much easier to adjust from the right side.

there shouldn't be any reason why not to put your vernier adjustors on the right side....if you have space that is....

I just put in the vernier adjustors from Mick Hemmings.......the installation instructions say that you should put them in on the left side, but I believe the only reason for this is because this is the only way to do it without removing the entire thru bolt....if mounting them while keeping the engine/gearbox cradle then you only need to tap the thru bolt enough to remove the end caps and shims and the old spacer...

I had the whole bike apart but put them in on the left side as instructed.

call whoever you got the Verniers from and ask....if you got them from Mick he'll happily answer your queries.....he's great with this sort of stuff.

good luck,

Eric

Guys,
Brain Tyree here in New Mexico came up with the idea and the first prototype pre 75iso threaded adjusters.
They are marketed through Hemmings.

The very first ones sold had a rather small diameter allen head set screw bolt to bear down on the inside threaded part of the iso.

It also had a nylon tip to screw down on to any raised threads.

I bought one of the first sets from Mick, and the rear iso, because of the motor rotation, want to naturally tighten.
The nylon tip on the end of the allen immediately shredded and I could not stop it from tightening.

Heinz Kegler lives here in Albuquerque and he took my isos and milled out the threads in the middle adjusting area so the allen
bolt now bears down on a flat spot. Heinz also tapped the adjuster holes to be larger so we could fit a larger, stronger, allen bolt.

I don't know if any of these improvements have been incorporated into the isos now sold. I hope so.

This past week, I removed both the front and rear iso for inspection and anit seized everything.

It doesn't matter which side you put them on.

A final tip, don't go by the quoted 10 thous clear feeler gage, after rebuilding slack them way off so you can reach on both ends
and freely spin the cradle endcaps. Test ride, should be NO vibration, then stop and turn the adjusters clockwise to take up
some slack, test ride.

When set up right, you should feel a little vibration in the footpegs and just a little in the handgrips, mirrors clear above 3500rpm.

Slightly, slightly too tight is better than too loose on the rear or you risk more swingarm movement.

This, in combination with Heinz's swing arm rings to secure the spindle forward against the bronze busings is "perfect".

John Schmidt

I had also installed a Heinz Kegler mod with the Hemmings Verniers.....

about the Verniers.......
can you check this webpage and confirm if these are the Verniers you are speaking of?

http://www.norton.norvil.net/mhiso01.htm


the verniers I have are the same except they have machined more spots to lock the grub screw (set screw)

thanks...

Eric

Eric, the early ones had no milling at all to bear down all, they were threaded all the way, the set screw with nylon tip touching a
thread just would not hold the iso on rear one.

Opening your link, I can see that a flat spot has been milled.
The size of the holes for the set screws are smaller than the one's Heinz tapped for me, but who cares so long as they hold.

Heinz milled the center and left thread on both sides of the inside iso, the new one looks like they probably measured just where
one would be setting the screw, Heinz just left a lot of room for adjustment, remember his fix on my bike was the prototype.

My commando, I am thrilled so say, was also the test bike when Heinz came up with the swing arm rings!

Heinz is cool, about 73 now, spent 17 years with Berliner the US east coast norton importer.
He has many stories of the early commandos, how they all had to be packed up and sent back to England for the early frame problem.

He is a pure featherbed man, and calls the commandos "limping camels" for their "gait" with "rubber snubbers"! He is SO funny!

I love the guy, he knows how to fix everything on my bike, he will be in Colorado at the National this week.
He has been asked to do a tech session.

IF there is anything Heinz or Brian Tyree or myself can help you with, let me know!
John Schmidt

The set I got is the new one from Norvil that doesn't require machining the front mount. They don't have the separate threaded parts like the Hemmings one in the link. They appear to be more like what was stock onthe MKIII.

highdesert said:

Heinz is cool, about 73 now, spent 17 years with Berliner the US east coast norton importer.
He has many stories of the early commandos, how they all had to be packed up and sent back to England for the early frame problem.

He is a pure featherbed man, and calls the commandos "limping camels" for their "gait" with "rubber snubbers"! He is SO funny!

I love the guy, he knows how to fix everything on my bike, he will be in Colorado at the National this week.
He has been asked to do a tech session.

John Schmidt

Click to expand...

About twenty years ago there was a post on BritIron that read: "Commandos are the Redhaired Girls with Long Legs of the motorcycling community. They are beautiful but they will ruin you in the end." It could have been Heinz, I can't remember.

Regarding vernier iso adjusters, the design that Mick Hemmings uses has a fundamental difference that I think is important. His adjusting collar floats on the threaded spacer. It is not loaded by the clamping force of the fasteners, meaning the 3/4" nuts. It's convenient that you don't have to loosen the nuts to make adjustments. But a bigger deal is that you are going to end up with the clearance you set instead of what you wind up with after you have retightned the nuts and bolts like on the MkIII.