New use for a Kibblewhite Performance valve spring (2013)

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I was shocked at the difference. The mirrors are clear and no tingling hands after a couple hours. I guess I will find out if it lasts over the next three weeks. Jim
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8 years and ~50,000 miles
 
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Time Warp

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I am kicking myself for not adding this mod when it was easy to do access wise.
My (titanium) spindle head steady might be fine now but over time if the (new) Isolastics were to sag that could risk contact in the spindle bore frame mount. (Maybe only at certain RPM's, who knows)

zz88 (1).jpg

That JC is a smart dude, a simple but effective modification over trying to hang the engine off the top frame tubes with a 'bed spring.
 

cliffa

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I‘m sure I saw a post from you yesterday about modifying the existing front ISO tube to achieve something similar?
 

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I‘m sure I saw a post from you yesterday about modifying the existing front ISO tube to achieve something similar?

I thought it might be possible but was wrong.
What I will do is have a hole in the JC frame mount for a bolt that threads into a stepped spring seat. (New AN inner and outer valve spring to keep it British)
Jacking on the bolt will lift the spring seat so a circular shim ( with slot to the central hole) can be slid under to alter the preload then the bolt tightened.
 

cliffa

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I did have an idea to get a piece of strong pipe welded to the bottom of the front ISO tube. The pipe would be large enough to contain the springs and would have a screw cap at the bottom so the pre-load could be adjusted. Then the top of the spring would sit directly under the ISO cross tube which has had the rubbers removed. ( maybe the smaller ones could be left for the occasional pot-hole) Obviously it wouldn't be in the same position as Jim's, but it would mean it could easily be reverted or transferred to another bike.
 
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I have played around with the spring on the headsteady but never found it to do much good. Maybe a little improvement if it was tightened as tight as it would go but then it would just break the stud or mounting bracket in a few hundred miles. So I tried something a little different.
I forget what all the spring is about, i guess take some weight of the iso's also allowing movement. Improvement with what? The iso's wearing out quick?

Wondered what this was about also
a linkage I made using one of my headsteady tie rods. I have removed the isolastic washers from the front mount and use the tie rod to eliminate the sideways play. That has been on there for several years. Jim
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As far as the spring mounting goes, dunno about the upper bracket, whether just held in place by spring pressure along with the described 'nub'
I just came up with the idea and welded it on a couple days before I posted it. I used a scotchbrite pad on a grinder to remove the paint before I welded it and mixed some two-pack and repainted it with a brush.

There is a cup machined in the lower bracket and a nub machined on the upper bracket to keep the spring in place.
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Previous post content removed being confusing to the specific thread topic.
The parts are machined now, the cup needs welding to the frame cross tube. I have a new AN valve spring set but as per a JC comment in the earlier part of the thread its rating might be to low.


cp.jpg
 
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I suppose with all the individuality out there, This KW spring is a one bike result but this part speaks volumes

comnoz:​

A couple brackets and a little welding and a Kibblewhite valve spring. It supports the motor enough that when the front iso bolt is removed the holes stay lined up.

I was shocked at the difference. The mirrors are clear and no tingling hands after a couple hours. I guess I will find out if it lasts over the next three weeks. Jim
 
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cliffa

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One thing to note : I'm pretty certain that Jim removed the rubbers from the front ISO completely and just uses the Panhard rod to control the side to side of the engine.

Edit : Found Jim's post. No rubbers in the front ISO tube. He also says KW springs were better than standard....

 
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a linkage I made using one of my headsteady tie rods. I have removed the isolastic washers from the front mount and use the tie rod to eliminate the sideways play. That has been on there for several years. Jim
 
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One thing to note : I'm pretty certain that Jim removed the rubbers from the front ISO completely and just uses the Panhard rod to control the side to side of the engine.

Edit : Found Jim's post. No rubbers in the front ISO tube. He also says KW springs were better than standard....

comnoz said:
"There is no rubbers or iso shims in the front mount. Just a spacer and a couple plastic caps to keep the dirt out.
The spring is easily removed by removing the long front mount bolt, this allows the motor to be raised just far enough to remove the spring.
The tie rod link keeps the front of the engine from moving side to side [like the original iso shims did -except the rod ends don't wear out quickly
"
 

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I will post this here for anyone interested who might not venture out of the main forum.

I found even with new RGM Isolastics the front sagged around 3 mm with the weight of the engine and no form of head steady pull spring, observed with the end caps removed.

I made this bracket that attaches via the bottom bolt of the Isolastic engine mount, a longer 3/8 inch and two 1/4 inch UNF bolts together lock it in place.

M.jpg ee.jpg

Unlike the JC version this has Isolastics in place.
The inner and outer valve springs are standard new AN parts, the inner spring is preloaded via a OEM stepped valve retainer inside the top brackets bore.
The compressed length of the springs ended up at 31.5mm (42mm free length) to have the front 1/2 inch bolt slide in with no resistance.
I might cover it with a length of rubber inner tube and grease the springs.

done.jpg

I can only assume any Commando with no assist spring and old Isolatics will have more than 3mm sag compression of the outer rubber discs, maybe the inner rubbers close to contacting the tube bore which might account for varying vibration bike to bike.
A big thanks to JC for posting this mod.
 
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