Dial gauge on isolastics

I was on a roll after repairing my centre stand and while underneath noticed one of the front isolastic shims hanging down out of the iso shim holder (no gaters fitted as previous head oil leak dissolver the old ones). Too hard to use the feeler gauge method so I used a dial gauge mounted on the main section of the iso and measured back to the frame mounting bolt. The method was to push to the left and then to the right and came up with over 30+ thou. Decided to dissemble and clean all parts and add 15 thou of extra shims, also noticed both Teflon washers or whatever the new stuff is were on same side, wrong wrong wrong! Reassembled and torqued to 25 ft/lb and there was no movement? Took out 10 thou and measured about 15+ thou using the above method. (IE only added 5 thou in the end)

First of all is this a valid method to measure clearance and secondly does the torque of the nut have a big effect on the clearance.

perhaps the nut was not torqued enough by the previous owner, nor was it assembled correctly.

Anyway new gaters fitted and I can easily rotate the iso shim holder so there must be some clearance.

Cheers
Peter R

What does it feel like when you ride it. ?
Thats the real test....

Both plastic washers on the same side?
any way your Dial gauge idea is good, providing you can get a proper push on each side, the torque on the bolt should have little effecf on the final clearance, after all the tube is not going to crush.

john robert bould said:

the torque on the bolt should have little effect on the final clearance

Click to expand...

Actually, it does, or at least that's what I've found when setting the Isos.

Yes, in re-thinking...if the adjusting nuts have a slack thread, this will be pushed closer to the shim's.

L.A.B. said:

john robert bould said:

the torque on the bolt should have little effect on the final clearance

Click to expand...

Actually, it does, or at least that's what I've found when setting the Isos.

Click to expand...

heres a picure of the cabbodle , flogged from ' britcycle ' site .



Flont
&
Lear . :?



a link for their ' instalation instructions ' . http://www.britcycle.com/Manuals/541_201_INST.PDF

Contrary to what some may think , It is actually a PRECISSION Engineered assembly . Being Engineering , its operation is facilitated by accurate SETTING ( we might call this ' adjustment )

The key to satisfactory OPERATION is Centraliseation , and Clearance ( unlike a Sustralian one I recently rode , thats footrests were vibro massagers , As In NO Clearance ) .

Heaveing the whole lot over to one side with a satisfactory lever , Measureing the GAP with a FEELER GUAGE , then reverseing leverage , so as to measure the opposite side ,
is getting carried away . But IF the freedom of the same Guage was altered Per Side ; It would indicate the clearance / shims Wernt Centralised . Or itd hit something .

Levering the REAR thus , and Checking the Front ; either ( both ) side / s , gets a indication of this .
If you HAVNT set it up CENTRALISED as yet , would be perhaps eronous to assume it were .

The Later thrust washers , rather than the white nylon ones , are to be prefered .
Some deranged olde gits would utilise ' Copper Coat ' as anti friction , there , in their assembly .

Angularity in the cradle causes binding , of excess clearance to evade .
The Norvil type ( or similar ) top steady makes location thus ' a plane ' ( assumeing ridgidity of frame ) rather than ' linear ' through lower mounts .

Id found 2 thou. clearance just chaffed , but cleared after a brief hideing . After erronously changeing into top entering a 80 knot sweeper brakeing from the ton , with the 23 tooth gearing .

The lateral osscilation of the cradle was detectable as it nodded twice through the undulations at a neutral throttle setting .On checking Iso Clearances at just past 5 thou ( 5 1/2 ) I set as previously mentioned and maintainted at 2 1/2 to 4 1/2 as over 4 1/2 the free lateral movement iduced uncertainty . I had fitted 5 m,m, dural trianular side plates to the head steady assembly .

For the best action you need to take the things seriously , not just as a afterthought . Uncentered its like a warp in the wing , if it were an aircraft .
Once set , likely only needs recentering at say 20.000 mile intervals. Keeping notes of shims & positions etc , makes it a piece of the proverbial , as per say shimmed o.h.c. valve adjustment .

Matt Spencer said:

heres a picure of the cabbodle , flogged from ' britcycle ' site .

Flont
&
Lear . :?

Click to expand...

Just to avoid any confusion, those are the vernier Iso kits so not what Peter R has, as the vernier kits do not use shims.

" Vibration up to 3000 RPM - Rear tight, Front OK
Vibration 3000-5000 RPM - Front tight, Rear OK
Vibration up to 5000 RPM - Both tight"

Duh isolastics like much of Commandoom is a sliding scale of mismashing among many components - so I flatly state you can't really tell much about isolastic optimization Until New Good Tires Fitted and Air Balanced for best ease of steering. Prior to that just set as able for least floppyness and least vibes.