Will you guys help me revalve my suspension?

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#1
Well, after surveying MANY suspension companies, I am torn at what to do. None of them will just sell me a valve stack to install on the stock piston(I want to compare the stock valving to the new). So, I came to the decision that I would like to revalve it myself. I don't care if I have to take the forks and shock apart 20 times, I WANT TO LEARN!!!.
Problem is I have no idea what changes will do or what I need to do.
Here is my proposition. When I get my springs and try them, then find what I do not like, I will dissasemble the forks first and post valving and what changes(wild guesses) I think will help. You must tell me if I am right or wrong, but DON'T just post what I should do to it. Lead me into it, give me pointers. I think you get my drift. I want to attempt to figure this out without blindly guessing at what to do. Then, one change at a time so that I can see what each thing does seperately, I will test them.
Heck, for the sake of knowledge I will get a small air tank( for the impact tools), some nitrogen and a vice on the trailer so that I can valve at the track.
Will you guys do this for me? I know you have helped people in the past(KTM shim shuffle series of threads) and now I would like the help.
Thanks.

BTW, the real reason I am doing this for all those that are going to say to send it out and save the hassle is because I feel it is the only way to learn. Most people (except for the race tech people) say that the only was to learn the art of valving is through experience, blood, sweat, and tears. I want to start now, at the age of 15. I feel that if I start my learning this early, I can be one of the best by the time I am out of college.

I also hate to pay someone to revalve my suspenders if I DO NOT know what they did. Bottom line, I WANT TO LEARN and there are no how to revalve books out there(hear that Jer, get writing!:confused: ).

Lets start with the basics right now; what is high and low compression and rebound. I CAN NOT get a straight answer on this one and it bothers me. Some say low is landings, some say braking bumps, some say high is landing, some say high is braking bumps. I am dumbfounded!
 
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#2
Aaron.

Race tech used to offer a video that showed how to revalve your suspension. Don't know if they still do, but, you can check at www.race-tech.com.

Good luck.
 

marcusgunby

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kawi there is alot of different opinions on what speeds the shock works on over various terrain-ask 10 experts and as always you get 10 opinions.An example for you, the 2001 Cr125 shock has a very burley stack that has lots of high speed and low speed compression and rebound.This causes kicking under breaking,so we wind out the LSC clicker and set the high speed comp to minimum and the problem gets worse-why who knows but if we reduce LSC shimming the kick goes away-wierd. The problem is suspension tuning is mostly subjective unless you have 1000 dollar equipment to measure everything.I will give you my limited experience gladly.What i can say is you will find out yourself by changing a shim stack(eg high speed) weather you adgree with others-bite the bullet.Be aware you are entering a zone that is sometimes fruastrating and tiring.Good luck.:)
 
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#4
Servus Aaron,

Marcus is right, things can get frustrating very fast without any results. IMHO revalving is not the hard part, the diagnose is! There are so many variables involved that it takes a lot of experience and time to find the problem itself. Once you know what is wrong, the remedy (sometimes a revalve) is comparably easy.

If you want to go the hard way start from scratch and ask your questions here. If you want some results choose a suspension tuner you trust, take his work as a starting point and then start asking questions.

Oh and get yourself a video camera or one of those digital cameras which can make short MPEG's (I use a Sony DSC-P1) - this is a tremendous help in finding your problems. Just post the *.MPG and everybody here on the net can watch and give his comments. For example take a look at

http://members.eunet.at/mpetkov/MX-Tech/MOV00003.MPG
http://members.eunet.at/mpetkov/MX-Tech/MOV00004.MPG

Have fun :p

Michael
 
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#5
Well, I tried to watch the videos, but when the "windows media bar" thing came up after the download was complete, a bleep then a warning that said that the file format was unsupported and then the URL came up. How do I get the videpo to play? I am TOTALLY computer ileterate so keep it simple.

Suspension-Can someone straighten up the high/low compression/rebound dillema? I still don't know who to believe. Also, what are some good books to help me throung this adventure? Do the race tech videos go inot any significant detail. I have heard all that they do is explain how to install a gold valve and well, I would like to know how to manipulate with shims.
 

sigar

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#6
Right on Aaron

I too want to learn how to do this "stuff". And, for exactly the same reasons as you posted. I'm new to bikes, had one for a little over a year, but there is nothing that has been done to my bike that I haven't done myself. I've learned a lot and totally dig working on these things, and learning about them. I'd ride around on a totally f'ed up bike that I tuned just for the pride of having done it myself, then pay someone else to do it. The only things left to figure out, are suspension and porting. So I will join you on your journey. Please let me know of any resources you find along the way, and I'll do the same. I think my biggest problem is that I'm not a good enough rider to really feel any effects of the changes I make, but I guess if I make them drastic enough I'll feel something. I envy you being only 15 and getting started on this stuff early enough to someday make a career of it. I'm already locked into my career, and in the world of bikes I'm a hasbeen before I ever got started. Anyway good for you. Now lets see what we can pry out of these suspender gurus.
 

marcusgunby

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Bieng able to feel what the bikes doing is just as important as the knowledge-without feel how can anyone make progress(video makes a huge difference obvoiusly)The racetech video does only show you how to install stuff.When you buy the valves you get a code that accesses there valving database.They have a series of std valving for different parts of the stroke(ie LSC/HSC, single/dual/triple stage stacks)so you mix a match to your needs.Its a good idea that seems to work well at educating people like us.As far as i know they are the only ones who encourage people to do revalving.You guys are lucky as i had to learn revalving on a WP PDS and dnot let anyone tell you that thats an easy task-2 pistons 4 shim stacks-minimum time of 1.5 hours to strip and rebiuld.The KX is a good base to work from-good linkage ratio-copied by Suzuki on the 250 and a tunable KYB shock thats a doddle to work on.
 
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shaggy829

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#8
hey guyes check out eric gorrs motocross & off road performance handbook
second edition . this book will help sort out different damping speeds .
 
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#9
Marcusgunby, I am VERY good at deciphering what the bike is doing. I use my senses along with video frame by frame. The problem is that right now, I can only remedy these problems with the clickers! I would like to go indepth. The problem with the video is,
1)I cannot put it on the net and have a tortise speed internet connection.
2)I am TOTALLY computer illeterate and cn't even figure out how to upload pics from the digital camera I just got. Go figure, it was supposed to be easy.

Not to brag about myself, but I pick mechanical stuff up very easily. Physics, chem, and math are like second nature to me. I have no trouble understanding things like this. One time is all it takes to get it into my head. I am very mechanically minded and adept. I have an intuative intellect for this kind of stuff. When I was 3 I did not beg my parents to bring me to toys r us, but rather home depot!! I wanted broken mechanical things for my B-day rather than toys. I rebuilt a car engine a 11 and it ran. I rebuilt a go kart a 9 and it was perfect. You get the point, I think I am destined to at least know how to do this, if not make a career out of it. I want to become an engineer and I feel that if I can learn this stuff now, there is no limit to the knowledge I will have when I am an adult.
I could probably figure it out without help if I had lots of time, a second bike so that I did not have to live with screwy suspension. But, the reality is that I have summer school for 6 weeks, don't have too much time, nor money and all I am looking for is you guys that know what you ae doing is to advise me on my though process and correct it. I just want to know if you would be willing to advise me. I don't want this adventure to be trial and error, but I would like to attempt to figure it out. Basically, I will post what I think and you will critque. Kindof saves me from TOO MUCH trial and error.
So, are you willing to help a revalving nebie??? C'mon, please.

BTW, the porting is all taking care of. As soon as I get my liscense(so I can drive there), a certain person(not mentioning their name so that they do not get swamped with requests for the same) has offered to spend a couple days with me teaching me some porting skills. Then, with these skills, and some books, I will "figure" out porting.
 

MN KDXer

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#10
Aaron,

Do a search for a thread in this forum titled "Rocky, Rooty Trail settings". In that thread, Mace, James Dean, and myself hacked around a lot of the calculation procedures to determine a quantification of a stack change. If you can find and read that, you should have some good ground knowledge to get started.

Most of the suspension guys will be pretty tight lipped about their stack configurations, and I don't blame them as it IS their livelyhood. But, if you ask some "I plan to try this:" type of questions, you might get some feedback. (I didn't a very warm reception, but that's a whole different story to take off line sometime.)

BTW, Good for you, with your determination! It sounds like you are a most inquistive young person with a bright future in engineering. :) Well, if engineering is a GOOD thing! :eek: (I can laugh, I'm a mech engineer, myself.) :)

Good luck with it, and feel free to post Q's. I don't get on here every day, but I'll try to help.
 
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#11
Servus Aaron,

How do I get the videpo to play? I am TOTALLY computer ileterate so keep it simple.
Basically it should play without any problems - at least on any recent Windows version. But don't bother, they videos are very short and just show specific sections of the track, like braking and acceleration or fast straights. I try to watch them frame by frame and see how the suspension is working. Often it is very surprising that the shock and fork behave way different then what I was feeling when being on the bike.

I'd say you just start working with your suspension and post the questions here - lets get some facts :cool:

BTW, the Eric Gorr book is very good, but it doesn't go into details on revalving. Very valuable basic infos though!

Michael
 

JTT

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#12
Kawie, sigar, I have been on the same "quest" for some time now. Here are some of my observations so far:
1) there are numerous ways to accomplish any given objective (ie: two different tuners will create totally different looking valve stacks, that react very similar)
2) the quest is not cheap....nitrogen, oil, shims, etc...not to be negative, just be prepared
3) There appears to be no actual "line" between compression and rebound "speeds". Kawie, your question about compression and rebound speed? this is why knowbody has given you a "real" answer, they all overlap to a degree, as do the valving that controls them. Basically, it's not black and white, just one big shade of grey ;)
4) I have also found that in making changes on your own stuff, the "placebo effect" is difficult to overcome, so be sure to be totally open minded and objective. You will often find that things are different than they appear.
5) revalving is slightly more of an art than a science. Many tuners rely on past trial and error settings to get started. That being said, records are critical and should be kept in great detail to be of any future use.

This is a great place to learn, as I am sure you are already aware. Read past posts and all present and future posts and you will slowly start to get a clearer picture in your head, but don't expect to challenge Jer any time soon :eek:

I personnally played with several changes to see the effect. Then decided to give myself a "baseline", I sent my stuff to a "Pro", then checked out what he did differently, and go a feel for what is supposedly "right" for me. Now I can further tune from there and get a much better feel for what is going on and the direction I actually want to go.

Good luck and keep posting!
 

MACE

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#13
KawieKX125, somewhere I read a bio on Master Wilke and you remind me of him. Maybe he needs a floor sweeper for the summer.....

Always question authority.

Real men know how to do their own suspension. Maybe even make it ] better .

If a tool needed for a repair costs as much as having a pro do the job - buy the tool.

Our world is full of weenies who are too lazy to figure out anything and are happy to just "send it off to ProCircuit".

KawieKX125, I salute you for refusing to be one of those weenies.

Now I expect your next post to reek of skanky suspension fluid!
:D
 
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#14
Well, I was thinking about that, but I have summer school. In two years when I am a senior, I can take the last 2 months off of school to go somewhere. Maybe I will go to work for Jer if he needs my help.
 

Jeremy Wilkey

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#15
Kawie,
You are alot like me.. Eric Gorr started tuturing me when I was twelve.. By 15 I was revalving my own suspensions and freinds bikes. My best Adviced is keep working on your goals and you will be succesful. I would say that if you had ever talked with me I would tell you yes it is years of hard work, but really a matter of just applying good science and then always refining. Suspension is a incredably challanging subject and one I love very much.

I don't truthfully like the nature of your question as I hate hadouts but understand that this is a far greater issue (I'm not making reffrence to the technical aspects, just the ecconomic, value of knowledge aspect) than just about any 15 year old can understand without a few years of life under your belt.

Anytime you want to ask theroy I'll be all over it and you can certainly come hang out anytime you like.


Best of Luck hope to meet you some day! Remmber you end up where set your compass..

Regards,
Jer