Fork oil/Fork Pre Load

[Phil/TX]

I am going to change the weight of my fork oil, what is the capacity for the forks?



Also am thinking of adding about 1/2 inch of pre load to the forks, ......anyone done this yet? :P

[dezrat57]

Hello Phil

I had similar questions on Tiger suspenstion, i called all over the world and nobody would give me the time of day! Tigerjay mentioned Phil @ http://www.aftershocks-suspension.com/pages/contact.htm

he has just had knee replacement so was kind of tough to talk to ; when i did,he has a vast knowledge  of oil weights,spring weights,valveing and etc. a pleasant 30min talk.

best of luck! dave

[Phil/TX]

U wouldn't hapen to be "desert Dave" from the Guzzi Forum?

[Chris Canning]

Hi Phil



If you've look through previous posting you'll see that i put Ohlin fork springs and 15wt oil in the forks,while i could have gone the revalve route,thought i could get what i was after without that hassle.



The problem i have at the moment is the front end has a tendency to patter at over 100mph,but i'm not sure if it's the oil wieght or that the tyre is worn and out of balance(and there's a good chance it is) if i find the tyre is OK,then i'll go back to 10wt and increase the quantity.



I see in your posting you asked about how much to put in,i just measured what come out!.



As for putting 1/2 inch of preload??,i think you'll loose the progressive feel of the forks,but may be worth a go,although i'd like to see you struggle putting the fork tops back on their bad enough without putting anything else in the forks!!!.



Chris

[Lucifertiger]

I too have tinkered with putting preload on the front forks & all it does make the front very bouncy on rough roads & dirt & it is a nightmare to put the caps back on. In the end I got some heavier front springs & 20weight fork oil. You have to find a balance between ride quality feel for the road & traction over bumpy surfaces. It still dives like a Russian Sub, still   but not as bad as before.

[morton_chad]

Wow. I changed my fork springs with springs from hyper-pro  and increased the fork oil to 15w per their recommendations. What an improvement. Nose dive is substantially reduced, corning much more stable, and overall much more solid feeling frontend. The downside is now the rear shock feels terrible and it took weeks to get the springs from Holland.  This is only a weekend ride confirmation, however, I am leaving on 6 day trip in October, so a better all around impression is pending.

[hellfire]

Hi,

i've just been reading about increasing the pre-load spacer on the front forks,

i've tryed this and now they seem to be bottoming out? have i done somthing wrong?? :oops:

the only other thing i done was topped up the oil,

any help would be appreciated,

Thanks...Andy

p.s some interesting items here: http://pages.cthome.net/bmantel/springs.htm (http://pages.cthome.net/bmantel/springs.htm)

[tomla]

boy do these posts sound familiar...increasing the oil weight without enlarging the comp. holes in the damper rods will get you harsh initial travel (and all thru the stroke, though the top end of the stroke can be somewhat softened by dropping the oil height 20mm).  you could use the 10wt if you brazed up the rebound hole(s).  then you've have softer initial travel, but the patter wouldn't be so pronounced.  

I'm going to do an emulator mod front end project without the emulators in a couple of weeks.  

what are you guys running for oil heights?

[Guest]

Hi,

i've just been reading about increasing the pre-load spacer on the front forks,

i've tryed this and now they seem to be bottoming out? have i done somthing wrong?? :oops:

You've probably put too much pre-load in meaning that the springs are becoming coil bound (solid) when the forks compress. If you're not careful you could damge the top caps when you hit a BIG bump.

[hellfire]

Hi Guys,

i've found out what i had done wrong! :oops:

i have read on a web page that you should have approx 170mm of space from the top of the threads to the oil level when the forks are fully compressed without the springs inserted,

i had done this but not fully compressed the forks! :shock:  

so when i re-inserted the springs & spacers the oil was compacting and giving the effect of bottoming out,

i have now put the correct ammount of oil and inserted a pre load spacer 20mm longer than the original,

i have yet to fully road test it but it seems much better,

Thanks for all your help!

Best Regards....Andy



P.S always remember if you are going to remove the caps from the fork tops always make sure the bike is on it's centre stand or lifted so the front wheel is off the ground!... these caps will take your eye out under pressure! :shock:

[Badger]

...i had done this but not fully compressed the forks! :shock:  ...

Oops! Don't worry, any idiot could have made that mistake.  

[hellfire]

Hi badger,

thanks for that mate! :lol:......  i was very stressed at the time :?

Cheers....Andy

[tomla]

just curious, where did you get 170mm....isn't factory 130mm?  and race-tech 180mm?  I'm thinking 140-150mm is the sweet spot for my fat ass.

url's appreciated.

[hellfire]

Hi tomla,

i forgot to add that i had used the Hagon springs with the 170mm space,

the url is: www.hagon-shocks.co.uk/FS_Apps_list.htm (http://www.hagon-shocks.co.uk/FS_Apps_list.htm)

Thanks...Andy