Rear Iso Vernier Installation

I am converting '71 Commando osolastics to Vernier.

The rear isolastic is roughly 1/8" too wide for the frame with vernier adjustment fully tight. I likely can make it fit by spreading the frame but no adjustment would be possible.

Or, I can remove 1/16" each side from the vernier end pieces. I do not like this option.

Advice, please??

(Yes, I checked the site for similar content)
Thanks!
Stephen

chasesa said:

The rear isolastic is roughly 1/8" too wide for the frame with vernier adjustment fully tight. I likely can make it fit by spreading the frame but no adjustment would be possible.

Click to expand...

Something would seem to be wrong with the assembly if it is significantly wider than what you removed as the vernier threaded adjuster shouldn't be wider than the pre-vernier 'collar'.

Are you sure you have the adjuster collar screwed onto the fully threaded end of the Iso. tube with the 'fixed abutment' fully screwed onto the partially threaded end (so the grub screw tightens against the plain section)?




Edit: Did you remove all the original shims?
The distance between the rear mounting plates should be 221.90 - 222.50mm.

chasesa said:

I am converting '71 Commando osolastics to Vernier.

The rear isolastic is roughly 1/8" too wide for the frame with vernier adjustment fully tight. I likely can make it fit by spreading the frame but no adjustment would be possible.

Or, I can remove 1/16" each side from the vernier end pieces. I do not like this option.

Advice, please??

(Yes, I checked the site for similar content)
Thanks!
Stephen

Click to expand...

If you got the kit from AN then it should fit. I've installed quite a few and have never had a problem. Like LAB mentioned, the fixed end must be screwed all the way on - look through the hole in it and be sure the tube is all the way to the inside.

chasesa said:

I likely can make it fit by spreading the frame but no adjustment would be possible.

Click to expand...

Also:
Increasing the gap of the factory* vernier Iso. can result in the frame being spread as the threaded adjuster is (should be?) in contact with the frame plate so increasing the Iso. gap by unscrewing the adjuster (stud or front Iso. bolt must be slackened*) also increases the overall width of the Iso. assembly* (and vice versa).

*(Not the Hemmings vernier)

Thanks all, for your advice, especially L.A.B. for dimensions. All has been valuable in helping me solve my fitment problem.
My issue was due to solely to powdercoat. I thought I could avoid some removal to limit future corrosion, however, a bit of lube will take care of that.
Regards!

My powder coated frame had to have it scraped off ( I can see the marks , thank gawd no one else can see them ) at the rear isolastics frame mounting points.

Isolastic adjustment tip : .. Take little notice of the instructions for adjusting isolastics... there will most probably be too much thread play for the "one and a half holes" thing to be valid and you'll end up with vibration from tight isolastic assembly. Instead DO IT BY EYE : get the rubber boot out the way (this, and putting it back after, is actually the hardest part!) slacken the mounting bolt. Lever the engine assembly away from the side you're observing from using a bit of wood. (get a mate to do this and shine a flashlight where you say so you have 2 free hands) Slacken the vernier bolt until you can see a clear gap of about quarter to half a mm. Push the soft washer round with a little screwdriver to make sure it's loose all round. (it'll be sticky with grease - take your time) Tighten the mounting bolts and try the bike. If it's smooth you can NOW experiment with TIGHTENING the isolastics untill you start getting a little vibration - then just back off a bit till it stops. WHY THIS WAY ROUND ? Because if you start with it all too tight, the vibrations will start breaking stuff - at worst : the frame.... Cheers. Oh and P.S. When isolastics work right, they work lovely.

Peach,
I just checked my adjustment yesterday and I would rather replace the horn than getting the boots back on!! I figure that there must be a better way to do this without tearing up the boots.

YING said:

I just checked my adjustment yesterday and I would rather replace the horn than getting the boots back on!! I figure that there must be a better way to do this without tearing up the boots.

Click to expand...

There shouldn't be any need to pull the boots completely off (if that's what you are doing?) but only enough to insert the feeler gauge (as I prefer to do the job once and with the Taylor head steady I've found no improvement with the Isolastics set less than 0.010").

The front boot should be no problem as it's easy to reach...


...although the rear is a little more awkward.


If you were to adjust using the 'holes' method then there shouldn't be any need to pull the boot back at all, front or rear.

I set mine by feel - tighten them until you feel vibration being transmitted, then back them off a hole or 2. Never have to disturb the boots. It can all be done without leaving the shop, hands on the bars, one foot on the peg, blip the throttle a few times. You can feel when it is right.

Les,
The problem I was having was getting the boot back in place. I checked my adjustment after a ride yesterday and am getting the process done with a lot less grief.
Thanks,Mike