Suspension - please explain.

[BigEd]

Howard, something is wrong. Two videos were posted in the thread on Modified Suspension, one by Chris Launders and the other by Chris and Tracy Tilley, showing the front end working as it should. Both were on twins but the lighter weight of a Comet should not make much difference if the correct springs are used. So the question that occurs to me is what is the front damper that you are using? If you have serviced it yourself then almost certainly it is not an AVO. A lot of the old dampers had the same rate of damping in both compression and extension. That is not a good idea. Please let us know what damper is being used and then we can work from there.

I think that it is an original damper that Howard has modified. I don't think he has a concentric headstock.

 

[Howard]

It's a Vincent damper with Paul Ennis mods on standard Girdraulics. It's working fine now, it was just the first mile it was pogoing, then it sorted itself out. I'm happy with all the lockdown mods I've done, and the Comet is finished for now. Next is getting rid of an annoying handlebar vibration on the Egli at 3,000 rpm - annoying because it's where they insist on riding on club runs.

 

[Bill Thomas]

Update.
I've done a few more miles, and a bit of adjustment and the rear suspension is much more comfortable. I fitted an hydraulic steering damper (just in case) and overhauled the front damper. The Girdraulics are still quite harsh now, compared to the rear but I can't see a simple way to improve the travel, and suspect increasing the travel would create other problems - all the pivots and bushes seem to be working well. The front end was pogoing a lot when I set off, but after a mile they settled down, I can only think the damper needed to charge itself, or maybe the ball valve I fitted had stuck.
Howard

I am convinced the comet needs the eccentrics more free, I tried to e/mail the Lady from e/bay, But She won't talk to me, about ZX1 Grease, I might try the semi lube grease we use on our Burman Gearbox.
But still not well enough, So it will have to wait.

 

[Chris Launders]

Bill, I found when changing from the eccentric bushes to needle rollers there was a huge reduction in friction, this initially didn't make sense until we realised it is not just down to the rotational resistance, but the angle of the link plays a huge part in this.
You have to imagine this but when the link is about level you only have the rotational friction, but as the link rises the out of rotation loading on the bush increases (which of course increase the friction) because the link is trying to pull the bike upwards, the change to rollers alters this as there is virtually no increase in friction.

That is my explanation as to what happens when fitting rollers, and why I had to alter the springing/damping completely.
Someone else may be able to explain it more eloquently than me though.

 

[Bill Thomas]

Thanks Chris, But I am standard and it only needs a NATS to be perfect,
Twins OK.
I have a road near me has a load of rise and dips , One after the other, I could see it getting out of hand,
If took too fast !,
But it's a 40 mph limit, So 50 plus is OK, And both Bikes the forks work as they should,
It's the sudden bumps that the Comet does not react quick enough for me.