fork compliance

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#1
My question is: What is the best way to get fork compliance (for rocks and roots) and bottoming resistance (for big whoops and g-outs)? It is my understanding that friction/stiction is the major culprit. So how do you best reduce friction/stiction? Hard anodizing or ti-nitride coatings? What is the cost of the options?
 

JTT

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#2
I think you will find that friction/stiction does play a roll, but as long as everything is aligned properly, this is not likely the main issue. Valving is usually the culprit in this problem. Although it is theoretically impossible to valve for all conditions, you should be able to get an exceptable compromise depending on the nature of your riding.

I personally have not played with "fancy" coatings, but I am sure they do make a difference. The problem is without the proper spring, valving, etc, it's kind of like putting a ram air breather on a Firefly, looks fast (well, not really, but you get the point), but it's advantages are lost.
 
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#3
JTT
I agree that valving is the most important part of suspension action. The fork, by design works best when the impact is dirctly in line with the direction of fork travel (zero degrees, if you will). Any impact that deviates from zero degrees when coupled with the co-efficient of friction, greatly diminishes the ability of the fork to telescope (compressing) properly, resulting in harshness. As noted in a thread the other day, conventional forks "make-up" for this by flexing rather than compressing. If a USD fork bends in this fashion (just below the lower triple clamp), binding and thus hardness results. I have found that in ~30 years of riding, the limiting factor in going faster (with relative comfort) for me (other than fear) is the ability of the front end to stay in contact with the terrain.
 

marcusgunby

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#4
I had a 99 KTM 125 with the 50mm WP convertional fork and found it very harsh so i wouldnt put too much faith in the good/bad theorys, a well set up fork will work good enough for 99% of riders.
 

dirt bike dave

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#5
FWIW, Factory Connection will Ti Coat your forks for $550. They say this will make your fork look like the factory teams, but their page make no claims about performance in any way. Every other service listed on their page hints if not outright boasts of substantial performance improvements. Makes me wonder if you could even feel the difference with the Ti coating.

To reduce stiction, I've heard the Paioli forks have the seals 'floating' in the leg, so that on initial movement, the seal moves with the inner leg a little bit. After the fork is moving, the seal hits a stop, but by then the fork has already begun to comply with the hit. Sounds great for the trail.
 

marcusgunby

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#6
I had those trick coatings on a 94 KX 125 and it ruined a good set of forks/shock.If you have coatings applied you first have to remove some material otherwise you loose your tolerance in the bushes etc and it ends up alot tighter than it should-read harsh:(
 
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#7
DB dave
You are correct, the "Blue Steel" Paioli fork (I have a set) has a 3 piece leg with floating seals. They work very well in the nasty root and rock infested trails that I ride.
Marcusgunby
I was told by Kevin Hines a few years ago that the Ti- coating made quite a difference, but it was best to get the forks well worn in before going Ti- for tolerance reasons.
The reason for the post is that I'm assessing my next cycle might be, and want to make sure that the suspension is up to the standard that I've become accustomed to. I can deal with less than perfect powerbands, shifting, etc., but mediocre suspension is not acceptible to me.
 

Jeremy Wilkey

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#8
TI coatings should not impact tolerance at all... Hardcoating AL will but not TI.. It does make a differance. We've been exspereimenting with seals as of late. If I find out anything useful, I'll update you.
Regards,
Jer
 
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#9
Thanks for the input
My next bike will most likely have USD forks (possibly Japanese) and I will most likely have to modify the suspension to work the way I like. I'm willing to spend the money on suspension if it works.
 
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#10
Jer
What $$ range is a person looking at to upgrade Japanese suspension units? What is the best bang for the buck? I (as well as the susp. tech. that has serviced my susp.) have noticed the difference in the oil that is changed in Ohlins/WP/Paioli suspension vs. Kayaba/Showa. The Japanese units often require many parts be replaced, whereas the Euro units just need/ seals replacement. The Japanese units often have appreciable amounts of aluminum sludge in the oil with relatively little use/abuse.
 

Jeremy Wilkey

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#11
TM,
I would not replace to Jap units.. I think the Paioli stuff is just fine when reworked..
As for the oil.. In recent years I have not had a problem with stock componets off of Jap bikes..

Regards,
Jer
 
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#12
Jer
I love my Paioli units on my TM (best I've ever used for enduro riding) and wouldn't think of replacing them. The Japanese units would be on a new Japanese bike (CR125 or WR250).
 
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#13
Hi All,

Better late than never. We use TI Nitrate quite a bit over here and our coatings go on at 5 micron thick. Pretty thin, not enough to have any issues whith bushes and seals.

Muddy:cool:
 

marcusgunby

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#14
Sorry to eloborate my forks had the Ti coatings and the hard anodising of the aluminuim tubes and it was the combination that took all the tolerance out of the bush area.Also not to start an argumant but if you Ti ontop of chrome like mine were, the bushes had a noticable gap at the ends which wasnt there before.If a coating is 5microns thick and is applied around a tube how much bigger is the tube-something for the maths guys.:p