fork oil level

[BIG FRED]

Hi all, Can any one please help with my question.
Changed a fork oil seals on my sp1 and replaced everything to a standard setting as far as im aware.
10wt oil 513ml or 135mm air gap. put all back in and hey presto as stiff as a board !
They were as plush as a very very smooth thing before. Backed off the damp and comp but still very stiff.
have i been given the wrong air gap or to much oil.
They may have had different oil oil than standard, before i had the bike, but no way of knowing

Any ideas please

[Sppete]

Just curious. what brand of fork oil did you use? Only asking because when I changed my oil from putolin to silkolene the dampening was much harder. It was still adjustable with the compression/rebound screws but quite different. Also, the 135 mm air gap wont stop the forks from moving not unless you measured it wrong and you've overfilled them so much you are getting a hydraulic lock.

Pete

[BIG FRED]

Hi pete
Thanks for getting back to me
Ive used silkolene but dont know what brand had been in before me ? they were really smooth when i first had the bike and only changed due to replacing the seals.
had a ride out to Darley Moor races on sunday and they are a lot firmer than before but they only be as they should from standard and i have been spoilt with the way they used to be.
Levels were checked correctly at 135mm as we have done a lot of seals on dirt bikes that we trail ride on so we know the importance of getting it right, but i couldnt get that plushness back on the road as it was before by altering comp etc.
Im a big lad and dont know wether a drop to 7.5wt will get me the same results as they used to be.
Cheers

[Sppete]

I've got the 7.5 in mine but I'm using Hyper-pro springs. I wouldn't imagine it would be a problem though as there is plenty of adjustment to go firmer if needs be. The only other funny thing I've had happen is striction. It felt like the seal was sticking to the stantion and gave a very harsh sensation until I got it sorted out with a judicious use of some vaseline and some very fine wet n dry. The seals were super tight when new and I think the vaseline helped as a better lubricant until they got bedded in. With the silkolene my compression is set about 3 click from fully open, I'd use 4 or 5 on track but I might be able to run it that light because the progressive springs won't let it bottom out no matter what.

Pete

[BIG FRED]

Hi pete
Thanks again for getting back to me.
Im glad to hear about the 7.5 wt oil.This will now be my next step to getting that plush front end back again,
Im not a track day lad so it would suit me better.
cheers for the advise.
Im off for oil this week and see if it works this time
will let you know how i got on

[BIG FRED]

Hi Pete
just to let you know 7.5wt oil all in and done.
Bike is back to normal now.
No more juddering throttle movements on every bump and pot hole.
10wt is not the way to go.
just nedd to do some final tweaks and all is good
Cheers buddy

[Sppete]

Cool. Glad it's starting to get where you want it. This bike needs a good front end set up to ride it with confidence and it's a lovely thing when you get it there Go steady on the road set up though. with all the rain and cold concrete it's not ideal out there at the mo
On the up side, it'll need tweeking all over again come spring and the fun starts all over again

Pete

[steelsey]

I serviced my forks with 5wt Motul and set an air gap of 125mm. They feel a lot better than before, got the right sag and they don't fade like before now.

I always use lighter oil possible to reduce the fading effect caused by the oil loosing it's viscosity as it warms in use, also the thinner the oil the less it has to work to maintain it's damping characteristics. The less viscosity the oil has, the less viscosity the oil has to loose. If the oil is viscous and the compression stroke is rapid, the oil won't be able to keep up. It will be pulled apart - cavitated - and with the rebound side unfilled, the fork will have no damping for the part of the rebound stroke causing irregular damping...

[BIG FRED]

JESUS ???
And i thought i had done ok doing them myself !!

[Sppete]

I serviced my forks with 5wt Motul and set an air gap of 125mm. They feel a lot better than before, got the right sag and they don't fade like before now.

I always use lighter oil possible to reduce the fading effect caused by the oil loosing it's viscosity as it warms in use, also the thinner the oil the less it has to work to maintain it's damping characteristics. The less viscosity the oil has, the less viscosity the oil has to loose. If the oil is viscous and the compression stroke is rapid, the oil won't be able to keep up. It will be pulled apart - cavitated - and with the rebound side unfilled, the fork will have no damping for the part of the rebound stroke causing irregular damping...

Cavitating fork oil??
What brand of chip fat have you been using?