Re: Linked Brakes...again

[Mike F]

I took the proportioning valve apart and took a pic of the components. Nothing was stuck, just a bit of sludge in there. Didn't make a difference to the braking - still dives at the front....maybe I'm just comparing it to my wife's Moto Guzzi.

[xjguy]

maybe front suspension is too soft-causing dive?

[Mike F]

Yes, you might be right though I've got progressive springs in but with the martini fairing.
Another thought that I had was that the spring has become softer through age...any evidence of springs doing this?

[MartyA]

HI Mike
Two items come to mind regarding stiffening the forks. The first is of course increasing the viscosity of the oil. Here the manual calls for SAE 10, I put in 15/20 last time. The dive is less alarming now, even with my Vetter.

The second is a tip I read about somewhere, adding a 1 1/2 inch length of PVC plastic tube on one end of the forks. I have not done this, but I may to try to improve the dive a little next time I change the fork oil.

[strom]

Hmmm... the other day I compared the GPz 600 forks with those of the XS... The kawa forks have an anti-dive unit that worked great on my kawa. The diameter and lenght is the same, but I don't know bout the brake and axle compatibility...

The principle of this anti-dive unit is, that when u brake, it locks the dive proportionatly to the power applied to the brake.

Some ppl don't like it, others said that the unit fails after 2000 miles, but I loved it and it worked great... stoppies were just too easy... couldn't help myself and eventually I broke the top-case mounting (the effect of slamming the rear wheel back to the ground).

I had linked brakes on the guzzi too, but I couldn't really say that it worked... good or bad... dunno... I was usually too scared to notice No fork brace press... the front wheel went wherever it felt like when braking hard. Never a boring moment with that bike... loved it.

The easiest and cheapest solution would be thicker oil and putting the plastic thingies in there... the anti-dive was just a thaught I was playing with for a time. Maybe on my 2nd bike... when I get one Definetly a guzzi (lemon or T3), but I won't sell the XS for it... definetly not after I saw the lemon described in the other bikes section...

Good luck!

LP

[Mike F]

Yes, I've got sae10 oil in at the mo so I'll try something a bit thicker. Thanks for the help.

[Mike Hart]

Mike, you can preload those springs too as suggested above, with a pvc spacer.

[MartyA]

I am working on old memory on this. I recall it was 1 1/2 inches. Maybe there is a more optimum length. Anyone?

[Mike Hart]

On a special or XJ, I'm pretty sure it was 3". On a standard, none.

I think Mike F has a standard, but a bit of preload might help anyway, if heavier oil doesn't do the trick.

[Mike F]

I guess that I'll change the oil first as I've tried changing the preload.
BTW, I had to get new bushes made up as the old ones were so worn and new ones were unavailable. The old ones were made from 'Tufnell' and I had the new ones made of nylon. Initally, they were a little bit tight and the gap had to be filed down a bit.
The bloke who did them informed me afterwards that most of the cost was in the setting up of the machine and it wouldn't have cost a lot more to do more.
Why do I always here that after the event!