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fork oil ?

PostPosted: Thu Mar 08, 2012 10:03 pm
by robb916998
I am in the process or re sealing the forks on the monza .
any way the factory manual is saying to use brake fluid or automatic transmission fluid for the fork oil.
seems pretty light to me ,any recommendations or experiences with normal fork oil ?? possibly a 5 or 10 ??

Also while I'm on the subject ,what is best to re seal the damper rod screw .I cant find the gaskets that they use listed in any part suppliers web sites.I'm thinking just re using the originals with a good coating of rtv silicon .??

really would like them to be sealed up good and last for a while !!
ANY THOUGHTS would be appreciated.

Re: fork oil ?

PostPosted: Thu Mar 08, 2012 11:00 pm
by cm250to999
20W with thoughts of seeking 30. No BS, put 20W fork oil in the Pantah and wished I had 30.

Newer stock Ducati is 8W. Pro build on 5W since 10% breakdown of 5W is a lot less than 20W.
I use 10W to give modern production fork some range. If older fork is very good condition, maybe 15W or 10W. Most worn early forks want thicker. My 95 900M has 8-9 year old 20W in it....finally about right now. ;)

The other thing is oil level. On the Pantah the suggested oil quantity was so minimal. I set the oil level at 6 inches from the top of fork with it fully bottomed in the slider. That increased the progression of "air" spring, enough to help a lot.

Re: fork oil ?

PostPosted: Sat Mar 10, 2012 4:43 pm
by fmcd92
Monzas with original fitment 31.5 forks are problematic with heavy fork oil 'cause they are not oversprung like most other bevels. 20w would be fine if fork specs are per original. Easy to adjust oil level afterwards if needs be. Do you already have half-decent shocks on the back?

+1 on all the above.

Cheers,

Fran

Re: fork oil ?

PostPosted: Sun Mar 11, 2012 9:46 am
by markk900
I couldn't tell the difference between oils (or even lack of oil altogether) with my Monza forks.....they weren't exactly compliant!

Mark

Re: fork oil ?

PostPosted: Sun Mar 11, 2012 3:32 pm
by AJ
Standard use in vintage bikes was ATF, which had a low viscosity rating - typically 10W or thereabouts.

Re: fork oil ?

PostPosted: Tue Mar 13, 2012 5:33 pm
by robb916998
Well thanx for the input guys ,I'm thinking a 20w at this point .

It dosen't look like the stock shocks out back as thay are a coil over set .To be honest I havent even looked at them as my focus all winter has been the front !

MARKK900 , I think your Monza is MY Monza , :D

Re: fork oil ?

PostPosted: Tue Mar 13, 2012 10:03 pm
by markk900
Seriously? Did you buy it from Barry? If so, great little bike. Let me know if you have any questions.....I probably still have some stuff for it lying around...plus I can explain some of choices made, such as those decidedly non-stock shocks.

Re: fork oil ?

PostPosted: Wed Mar 14, 2012 2:34 am
by 4theloveofducati

Re: fork oil ?

PostPosted: Wed Mar 14, 2012 1:42 pm
by cm250to999
here this will clear it all up (not)
http://www.peterverdone.com/wiki/index. ... sion_Fluid
Even different brands of fork oil will give different results.

The consensus that ATF is more like a multigrade seems to be worth calling it a bad choice (read the article to see why it was chosen). It will change with temperature much more than "fork" oil.

My suggestion of 20W may be on the thick side, 15W might be a better start.

Any fork, the spring must be right first. Sag must be correct (20-30mm ?) without excessive preload. Rebound damping is about right when the fork returns to home position without trying to start another down stroke. It's a bit of a trick to give the fork a good push down, then let the bike react freely. Compression damping works with the spring. When all is in the ball park, a click of comp. damping and/or spring preload give similar result. Just a description, knowing early forks are not adjustable...neither are the bargain Showa on my monster.

The Pantah now acts ok for a street fork with 20W. Before it took a long time to settle from an input.

Re: fork oil ?

PostPosted: Wed Mar 14, 2012 7:08 pm
by markk900
Wow - so glad the lil monza ended up at another good home....and for the record, all this talk of suspension tuning meant nothing to me when the bike was being built.....keep the tires off the fenders was the order of the day since the bike didn't generate enough momentum to require the finesse that a well tuned suspension would add.

Here's an early shot.....I am not sure but this was probably not the lap the top of the carb fell off jamming the throttle wide open...which actually didn't matter much as the bike handled so well and had so little power!

http://i197.photobucket.com/albums/aa22 ... G_0007.jpg

Re: fork oil ?

PostPosted: Thu Mar 15, 2012 12:16 am
by 4theloveofducati