Pre-load sleeves

[Projectman]

Well, having finally managed to get around to stripping the front suspension I have to say that I am impressed by the fit and finish on the 907ie . I am sorely tempted to keep this bike now!

I am not so impressed that I have no evidence that the the fork oil has ever been changed in 22 years and 20,000 miles! There is nothing in the service records and receipts that came with the bike to suggest that it has.

So it was with some trepidation that I inspected the fork internals (Forking Ternals?) but I got a pleasant surprise. There really isn't any sign of wear: Perhaps it's the low mileage?

The only queries I have are -

1.Should I replace the springs while everything is is apart?
Both springs measure 280mm

2. The pre-load sleeves look knackered. They both have a distortion, a swelling at the spring end, which made them difficult to remove from the fork tubes. As a result of the hard life they appear to have endured they also measure slightly different lengths too.
The sleeves are made of some kind of bluish/grey plastic, which is harder than the kind of plastic you get from the plumbers merchants.
I think the plumbing type tubing might be too soft for the job.
I want to do the job properly and I'm wondering whether a metal tube (of the kind I've seen in other motorcycle suspension set-ups) might be worth considering.
I've bought springs from the Hagon company in the UK previously and they have helpfully advised about the correct pre-load sleeve length for their springs.
Does anyone know what the length of the OEM pre-load sleeve is/was originally, please?

I have searched around the forum but I only have a limited amount of free time at present, so any help would be much appreciated.

Thank you in anticipation.

John

[englishstiv]

KEEP IT........ You know you should you shouldn't need to replace anything except the rubber seals and covers my own bike that seems to of had a history (looking at other issues and damage) of fairly constant front wheel popping has no wear after 30 odd thousand miles.

[ducinthebay]

The preload tubes can be made of anything really. Any steel or aluminum, even copper tubing would probably work just fine. Some have used PVC plumbing pipe in the past, but I think that it will break down after some time.

Ideally those two tubes are the same length. In the M1R and similar forks they set the preload, and initial ride hight and sag. So you should adjust the length to match the back sag. Ideally, the sag should be the same front and back.

I'll assume the spring rate for the front and the back are acceptable to you, and you don't feel you need to change them.

Cheers, Phil

[Projectman]

Thanks for the replies people.
I think I will just sort out some suitable tube and see what the bike is like to ride (eventually) and whether I can justify keeping it, 'What wiv me achin' joints n'all guvner'.

[ducbertus]

Hi Projectman,

I would suggest to replace the springs by a set of Hyperpro's or White Power with progressive spring rate.
this makes the frontsuspension fairly sensetive at the beginning of the travel, while the raising stiffnes avoids blocking during hard braking of large bumps.

preload bushes are no longer required than.

Bertus

[Projectman]

Thank you for the suggestion Bertus.

If I change the springs, I was going to go for Hagon; I've used them before and was well pleased with the results. They're a bit cheaper, and British too (well, it matters to me! ). Even if the other makes you suggest are better, I doubt that I'd notice the difference.

I think I would like to keep this bike in preference to the other two that I own; A Triumph 800xc, and a 1997 Kawasaki zx6r (not running at present).
Everything hinges on whether or not my shoulder can be fixed. I can ride the Triumph all day without any problems; It's a great 'do-it-all' bike but not so exciting, if you know what I mean .
I suspect that my time on the Ducati would be limited, even with a good shoulder, but that an hour spent riding it would be worth two hours on my other bikes. The road tests that I've read all portray a machine with Honda VFR ability and Ducati soul .
I can't wait to try it.

John

[ducbertus]

Hi John,

the Hagon springs will do the job without any doubt. I've found my White Power springs on Ebay for € 99. the assembly I did it by my self.

I whish you all the luck with your shoulder. It would be a pity not being able to ride the lady properly.

Bertus