Compresion pre-load

[Allan1956]

Well I give up.

 

I've done the searchs and read the threads on front and rear suspension.

 

My 2002/3 LeMans seems great at speed and straight line, but has "shook its head 3 times" mainly on cornering. I've checked and increased tyre pressures, rear preload etc, but I'm still not happy with my front forks.

 

The threads here and elsewhere talk about increase/decrease compression, rebound and or front preload. Each to their own. BUT, front preload and front compression?

 

My manual says my Lemans has hydraulic telescopic forks with separate adjustment during rebound and spring pre-load. So by this I take it the bike has no compression adjustment (original suspension- none of that fancy Ohlins yet). So does that mean the preload should be set and then left or should it also be treated like a"compression" adjustment

 

It seems that reducing the preload just makes the bike sit lower in the front and not necessarily making the front end softer on compression. I know the difference between front preload an compression but I seem to be finding it had to reach a proper setting and the "standard" setting set by guzzi are not satisfactory for me at approx 86kilos. Any ideas?

 

Thanks

Allan

[Guest Brian Robson]

The stock Marzocchis have adjustable compression and rebound. There is no adjustment for preload (2002 LeMans with "C" and "R" stamped on the top of the forks).

I weigh a little more than you (88Kg) and I adjusted the load on the forks by adding more oil (50mls to each leg) and using a lighter oil (Bel Ray 5W). The lighter oil in my opinion lets the fork respond more quickly while the extra oil reduces the air gap. I also raised the forks in the clamps by 2mm. Compression is set 4 clicks in from minimum (i.e. backed all the way out then turned in 4 clicks), while the rebound is 6 clicks in from minimum. I think I get a very supple and controlled ride and I get no cupping on the front tyre (BT 012 @32 psi).

[gthyni]

Brian,

I think i've heard that the 2003 and on has a different Marz fork

from our earlier bikes had.

[al_roethlisberger]

Yep, the forks are different as of 2003+

 

The 2003 forks are 43mm, instead of the 40mm of the 2002.

 

The 2003 43mm Marz forks have a larger, hollow front axle.... instead of the solid screw-in bolt of the 2002 and earlier bikes(and 2003 and earlier Ohlins equipped bikes, like Rosso Corsa).

 

The 2002 forks have compression and rebound(separate in each leg), but no preload adjustment.

 

The 2003 forks have compression and preload, but no rebound adjustment. And compression and reload are in both legs on the 2003+ bikes.

 

 

Unfortunately I can't answer your question about optimal settings for the Marz, earlier or later models

 

It sounds like you have a 2003 model from your signature, but did you see this recent thread on optimal 2002 Marz settings?

 

http://www.v11lemans.com/forums/index.php?showtopic=3437

 

 

al

[Allan1956]

Thanks all for the info.

 

Yeah Al, I read Graham's post and found it really informative. To some extent I am basing my changes on his info. I find that my sag figures etc are close to his but haven't yet had a chance to take the bike for a spin.

 

Well there you go, I always thought that my bike was a 2002 model 'cause I ordered the bike in June 2002 when I first saw it appear on the net. When it was delivered in December 2002 the paperwork said it was a 2003 bu I just thought that it was a marketing gimmick/ploy because I had to wait sooooo bloody long.

 

As for the front forks, the manual says that it has preload adjustment (if you can trust the manual and it's translation). The wording I used in my initial post was from the manual:

"The motorcycle is equipped with a hydraulic telescopic fork with separate adjustment of shock absorbers during rebound and spring preload"..Nil about compression Mario?

"Vehicle attitude setting-each fork leg has an uper screw =A= for adjusting hydraulic braking during rebound and a upper nut =B= for adjusting spring preload." blah, blah blah. But it doesn't talk about any compression adjustment.

 

Hmmmm. just have to keep playing unless someone can come up with something else.

 

Thanks,

Allan.