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Teach me about revalving suspension (2009 KX450)

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I'm a stubborn do it yourselfer, I insist on doing maintenance myself but it sometimes leads to doing things 2-3 times to get it right.

 

I bought a 2009 KX450 last winter that was sprung for a 250 pound rider. I replaced the fork and shock springs with the right spring rate for my weight (190 pounds) and since I don't know much about revalving I took the chance that I'd have enough adjustment in my clickers to fine tune.

 

So now I have my sag set properly, but the 450 seems really harsh still. I keep reading your post about your bike feeling "plush" and I don't get that at all. My last bike was an old XR400 so I've probably NEVER felt a plush bike. I plan to ride 30% trails, 70% motocross.

 

I have all the basic suspension tools needed to take the forks apart but I've never rebuilt a rear shock before.

 

-Do I need to revalve my forks and rear shock?

 

-Does revalving just adjust the shim stack ups I've been reading about?

 

-What special tools would it require?

 

-If I pay someone to do it, what would it cost?

Edited by jermag24

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In my 40+ years I have done the tuner revalves, the spring and oil changes and everything in between.  Have had ONE revalve come out really well. The rest(many) have been worse than my carefully adjusted stock forks. Lots of money wasted and riding time lost. On my next bike if the oil and spring adjustments are not adequate I will do the RaceTech deal myself. I will never spend money with another tuner. And I don't care if he offers a full money back guarantee. I know several guys who have gone the RaceTech route with great success in spite of the negative bs  many post.

Edited by YHGEORGE

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In my 40+ years I have done the tuner revalves, the spring and oil changes and everything in between.  Have had ONE revalve come out really well. The rest(many) have been worse than my carefully adjusted stock forks. Lots of money wasted and riding time lost. On my next bike if the oil and spring adjustments are not adequate I will do the RaceTech deal myself. I will never spend money with another tuner. And I don't care if he offers a full money back guarantee. I know several guys who have gone the RaceTech route with great success in spite of the negative bs  many post.

 

I'm getting to that point, I've spent far more hours getting my used bike caught up on maintenance and set up than I have actually riding. Don't get me wrong, I love working on bikes but sometimes after spending a bunch of money on special tools and weekends turning wrenches it would be worth the money to send this stuff out. I was talking to my wife about it and she reminded me of the thousands of dollars I've saved doing our clutches, timing belts, fluid changes, shocks and brakes. It's probably just time to spend the money to have my suspension set up right.

 

I separated my shoulder this summer after high siding in a turn that I thought I had set up right. I've been out of riding for 8 weeks now and have replayed my crash over and over in my head and I think it's a matter of improper suspension setup. Thanks for the reply, any additional input is appreciated!

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Don't mess around with suspension revalving yourself. It takes many years to master and isn't something you could get right just tearing them apart once and putting in different valves. Like he said it'll be too many hours wasted. I've had suspension revalved for me, and its the greatest money I have EVER spent. It's definitely a priority to set up suspension right before spending money in the motor.. wish I knew that before!

Different valve shims* sorry

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I'll toss out my opinion since you asked... First, let me state I have never had my suspension worked on by a professional, or race shop.

 

If you can work on your own cars, you can do the mechanical aspect of disassembling, and reassembling your forks & shock. That is the easy part. The hard part is knowing what shims you need (thickness & diameter) and in what location/order. This is the part that you will need someone to help you with.

 

If you decide to go down this path, you can start by reading here:  http://www.thumpertalk.com/topic/327668-diy-04-450-suspension-re-valve/

 

You need to learn the nomenclature of all the parts & pieces inside those forks & shock before you begin this process. Once you understand how the different pieces work together, it will make sense. Then once you have a basic understanding of how the internals work, & their location, you can then disassemble your forks and record the shim stacks, and likewise the shock.. Once you have the stacks recorded, you can post the stack on this forum, and hopefully a professional will post up what changes you need to make. This is how I was able to do it. I did both my forks, and my shock, with shim stacks offered to me by other people on this forum. Other people who were gracious enough to offer their time and expertise to help out a fellow rider. I can't say THANK YOU! enough to those who have helped, and continue to help the rest of us.

 

On my forks I had to go back in a total of 3 times to make minor changes to get them PERFECT. The shock was a home-run on the first try ONLY BECAUSE of the professional guidance I received from Cardinale (a poster on this forum).

 

You need to be specific about what you don't like about your suspension and what you are trying to "fix".  Most posts I have read on the subject state that setting up a dual-purpose suspension is always a compromise. You state 70% MX & 30% woods. Well, just know that you need the suspension set up more for MX so it is not going to be as plush in the woods as you hope it is going to be. I guess I'm trying to tell you to be realistic in your expectations and know that a dual-purpose suspension that excels at both MX & Woods/trails is not realistic. The suspension may be really good at one, and only okay at the other, or it may suck at both.

 

Ultimately, the magic exists in understanding how the shims & shim stack, & piston, & bleed, oil level, oil weight, and many other elements will work together. That part even I don't fully understand and may not ever. But, if you can pull the stack apart, and follow basic instructions on which shims go where, and put it back together, then you are on your way. There are MANY shim stacks already posted on the internet that you can pattern to see how they will work in your bike. Just remember to record your factory shim stacks so that if ever things get hinky, you can always go back to stock as a re-starting point.

 

I've gotten way ahead of myself. Start with the post I linked above. If you can read every page of that and make sense of it then this is for you. If it reads like a foreign language that you can't grasp.. Race Tech might be your solution. 

 

If you try this and have questions, there are many knowledgeable people here to help you.

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2009 KX450 forks are known to blow through the stroke and feel harsh. The MID valve needs to be revalved. You can do it yourself if you have the proper know how and want to save money. I personally use Race Tech because they have excellent customer service and by doing it yourself you can feel what you changed. Don't let some company talk you into a expensive revalve because it always needs to be revalved. A $300 revalve turns into $600, $900 ...... If you do it yourself it will cost you $15 in oil for continued revalving. BTW Race Tech has classes you take.

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I paid a shop to revalve/tune my suspension for me and my riding discipline. My suspension was worse after the revalve. So I decided to learn how to do it myself.

If I can do it, anyone can. I will never claim to be a master suspension tuner nor do I want to be a master suspension tuner. I have tuned the suspension on 3 of my different bikes.

I learned how to tune my suspension via TT, TheDogger and the Race Tech suspension Bible.

If you have the time and willingness to learn, you will improve your suspension.

I am very thankful I learned how to tune my suspension and I learn more every time I tear down my suspension and make changes.

Good luck!

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I've been looking in to what parts will cost me to do a thorough revalve job myself. I've included fork/shock rebuild kits since it's probably a good idea to replace wear items since I'd be taking that far anyway.

 

Forks:

 

RT Gold Valve Compression kit: $131.00

RT Gold Valve Rebound Kit: $131.00

Pivot Works Fork Rebuild Kit: $63.00

 

Shock:

 

RT Gold Valve Shock Kit: $130.00

Pivot Works Shock Rebuild Kit: $70.00

 

Fluid: $30

 

Grand Total: $555.00

 

I may do the forks first and the shock later to break up the cost AND because the rear feels pretty good while the forks feel harsh and unbalanced. Also, my rear shock has a 5.5 spring while RT says I need a 5.7 so I'd have to add $100 for a spring too.

 

Do the shim stack recommendations that come with the RaceTech revalve kits seem pretty good in your experience? I like that it comes with shims AND a guideline for what stack up to use!

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I did my forks the RT route, and was pretty happy with what I got over the stock valves. although I never tried to restack the factory valves. I went one step stiffer on all recommended settings for the compression stack, not fully understanding their implications to feel. I then bought the Suspension Bible and read and re-read it. Its definitely a must have to understand the "timing" of the valving and its respective effect.

 

READ,READ,READ... AND WRITE EVERYTHING DOWN!!!  Mechanically its not that difficult, wrapping your brain around it will be the worst part.

 

BTW, I also went with the Pivot Works kit, and I found the pieces went in ok, but one of the bushings and one of the seals didn't fit perfect, and the seals absolutely wouldn't seal on my particular set of fork tubes... I would recommend getting those parts from a factory dealer, or Suspension Direct.  JMO

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I've been looking in to what parts will cost me to do a thorough revalve job myself. I've included fork/shock rebuild kits since it's probably a good idea to replace wear items since I'd be taking that far anyway.

Forks:

RT Gold Valve Compression kit: $131.00

RT Gold Valve Rebound Kit: $131.00

Pivot Works Fork Rebuild Kit: $63.00

Shock:

RT Gold Valve Shock Kit: $130.00

Pivot Works Shock Rebuild Kit: $70.00

Fluid: $30

Grand Total: $555.00

I may do the forks first and the shock later to break up the cost AND because the rear feels pretty good while the forks feel harsh and unbalanced. Also, my rear shock has a 5.5 spring while RT says I need a 5.7 so I'd have to add $100 for a spring too.

Do the shim stack recommendations that come with the RaceTech revalve kits seem pretty good in your experience? I like that it comes with shims AND a guideline for what stack up to use!

Jermag24,

You don't need race tech valves or shim charts to do a adequate revalve. I have had satisfactory results using oem valves. My $0.02.

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