New Isolastics and vibration

I used to sell a lot of Commando parts and at one time there used to be on the market pattern MK3 rubber assemblies that used to do what you are talking about. I think it was due to a different rubber compostion. I cannot remember anyone saying if it settled in or not.

Previously wrote:

In case anyone was wondering why there is no narrative in the original posting - I created the message using windows vista. Clearly this message service is incompatible with vista as it wouldnât allow access to the Body Text box. Iâm now on a different pc using windows XP and all is well.

Here is what I originally intended to type:

I recently restored my 850Mk2a and in doing so fitted a vernier front and rear isolastic conversion supplied by RGM âMotors - setting them up as per the supplied instructions. Prior to restoration the ride was super smooth. Now, up to 3,500 rpm, there is very harsh vibration. Beyond 3,500 rpm the ride is quite smooth. I have tried varying the vernier adjustment to give both greater and lesser clearance but this makes no difference to the vibration.

Has anyone else experienced greatly increased vibration post fitting of new isolastics? Can I expect things to settle down with more use? - i,ve only done about 900 miles so far.

A point to note is that other than removing the head and barrels for cleaning and painting I didnât do any engine work as part of the restoration because I had previously rebuilt the motor a year or so before taking the bike off the road.

Thanks to anyone who is reading.

Peter, I had same computer problem, and loaded GOOGLE CHROME, this allows you to type in the box, like I am now !

Previously wrote:

Previously wrote:

Peter, I had same computer problem, and loaded GOOGLE CHROME, this allows you to type in the box, like I am now !

Or you could own a Mac.

Previously wrote:

In case anyone was wondering why there is no narrative in the original posting - I created the message using windows vista. Clearly this message service is incompatible with vista as it wouldnât allow access to the Body Text box. Iâm now on a different pc using windows XP and all is well.

Here is what I originally intended to type:

I recently restored my 850Mk2a and in doing so fitted a vernier front and rear isolastic conversion supplied by RGM âMotors - setting them up as per the supplied instructions. Prior to restoration the ride was super smooth. Now, up to 3,500 rpm, there is very harsh vibration. Beyond 3,500 rpm the ride is quite smooth. I have tried varying the vernier adjustment to give both greater and lesser clearance but this makes no difference to the vibration.

Has anyone else experienced greatly increased vibration post fitting of new isolastics? Can I expect things to settle down with more use? - i,ve only done about 900 miles so far.

A point to note is that other than removing the head and barrels for cleaning and painting I didnât do any engine work as part of the restoration because I had previously rebuilt the motor a year or so before taking the bike off the road.

Thanks to anyone who is reading.

Have you had any luck with your vibes! I too have the same symptons. It does`nt matter what i do to the settings the vibes are always in the range of 2500rpm but nice and smooth above 3k. I always set them with the bike off the centre stand. I loosen and retighten the headsteady bolts after every adjustment. No change. It is annoying as 2750rpm on my bike is 50 mph which most trafic seem to day nowdays.

Have you had any luck with your vibes! I too have the same symptons. It does`nt matter what i do to the settings the vibes are always in the range of 2500rpm but nice and smooth above 3k. I always set them with the bike off the centre stand. I loosen and retighten the headsteady bolts after every adjustment. No change. It is annoying as 2750rpm on my bike is 50 mph which most trafic seem to day nowdays.

Hello Peter,

It is entirely possible that the ends of the mountings are not truly square. This would allow the vibration which you are experiencing. Isolastics are a black art, and can best be examined by reading the article on the internet; just type 'the world's straightest Commando' into Google and see what comes up. The fittings need to be completely square in relation to the frame. I don't use the standard method for my Commando; I alter the settings when the ride becomes too harsh and use the same section of quiet, bendy road to evaluate my findings. At present, my 'bad patch' is between 2,200 and 2,500 rpm; after that things quieten down considerably. Isolastics should always be checked and adjusted with the machine off the centre-stand. The machine also benefits being left on the side-stand while it is parked in your garage.

Best wishes, Colin Cheney, somewhere in England.

The use of the sidestand is debatable. With the bike on the centre stand (mounted on the engine cradle) the weight of the engine and gearbox bearing down on the rubbers is off loaded from it's state when being ridden. Unless we ride 24/7 that's probably 98% of the bike's life. Until I replaced my early commando frame mounted centre stand with a later cradle mounted stand, there was definate indications that the engine and gearbox were sagging under their own weight, to the extent that the cradle was touching the cross member. (the cross member is much further back on the early frames and my iso rubbers were probably well sha--ed out) The Commando frame is particularly flimsy and any bending force on frame tubes should be avoided IMO. Something else to consider is any oil that would pool in the bottom of bearings when stationary and horizontal, will drain from a bearing when tilted (on the side stand) This initial lubrication will suffice until the oil from the pump appears on the scene at start up. I rarely use my sidestand as the twisting leverage on the lower frame tube is massive, particularly when loaded up.