WR Rear Suspension Problem

[Ricktc]

Hello all, I have a few questions about a problem that has recently occured with my 03 WR250F. I set the sag shortly after I bought the bike 2 months ago, got it dialed in perfectly for the type of riding i do, and the bike was performing great. Recently though, I have encountered a problem with my rear suspension and I don't know what may have caused it. First of all, the bike feels VERY stiff and springy in the rear, WAY more so than it was after I adjusted the sag to 3.9 inches and the clickers to fairly soft. It seems like once it hits a certain point in the travel (roughly 1 inch compressed from normal height with no weight on it) it gets VERY stiff, it doesn't seize up, but the suspension is very stiff and springy once it hits this point. I am tending to believe the bearings are not the problem, since they would have to be acting like a torsion bar to cause the suspension to act the way it is. The suspension rebounds fine, there are no rough spots in the travel while it is rebounding, it just rebounds rapidly and is very stiff. As far as I can tell the bearings are all functioning properly and are not worn out. This change in the way the suspension acts came about rapidly, the first time I noticed it was after unloading the bike and getting ready to go for a ride, not during the ride prior to this one. The best way I can figure the problem out is that something inside the shock (like the valving) is not allowing the fluid/gas to travel back and forth into/from the reservior, therefore stiffening it up greatly. Is there a way to refill the gas and fluid inside the shock back to the levels they should be at? Also, I will grease the bearings as soon as I have time to take it apart, do you think this will solve the problem? I looked in my manual very extensively and all it says about this subject is to check the bearings, but like I said it doesn't seem like the bearings are coming into play in this instance. Any help is appreciated, thanks.

-Rick

[Ricktc]

Anybody? I searched and found another thread talking about the same problem, apparently it's fairly common, however the only real answer I got from that thread was 'it needs to be taken apart.' I can take it apart but what do I need to do when I get it that far? Would it be a lubrication problem inside the shock?

-Rick

[Wooded]

It's hard to say what is actually going on in your shock. Your going to have to take it off anyway... so take it off and check the free movement of your linkage/swingarm.

[huffster]

Sounds to me like something in your shock or valve shim stack may have broken and is making the shock action strange. My guess is you have lost your nitrogen pressure which is causing the shock to not dampen correctly....You can test this by removing the shock from the bike, placing the shock in a vice, removing the shock spring and pushing in the shock shaft and watching how it returns...The shock shaft should return at a nice slow speed taking about 1-2 seconds to extend all the way.

1. If it does not return at all, then you have lost your nitrogen charge and the shock needs to be rebuilt.

2. If it returns very fast, your rebound stack could have broken shim or something else is wrong.

Either way, you should send your shock (or take it to) a suspension technician in your area and have it properly serviced !

[Ricktc]

Yeah that's what I plan on doing, just wanted some input as many of you guys have probably encountered the same problems. I'll pull it apart and go from there.

-Rick

[Ricktc]

Sounds to me like something in your shock or valve shim stack may have broken and is making the shock action strange. My guess is you have lost your nitrogen pressure which is causing the shock to not dampen correctly....You can test this by removing the shock from the bike, placing the shock in a vice, removing the shock spring and pushing in the shock shaft and watching how it returns...The shock shaft should return at a nice slow speed taking about 1-2 seconds to extend all the way.

1. If it does not return at all, then you have lost your nitrogen charge and the shock needs to be rebuilt.

2. If it returns very fast, your rebound stack could have broken shim or something else is wrong.

Either way, you should send your shock (or take it to) a suspension technician in your area and have it properly serviced !

Thanks for your reply. I am thinking scenario #2 is the likely one. Would it be possible to take the shock apart myself and re-shim it, or should I play it safe and take it to a suspension shop? I am confident I can do the work as long as there are no special tools/parts needed.

-Rick

[huffster]

Thanks for your reply. I am thinking scenario #2 is the likely one. Would it be possible to take the shock apart myself and re-shim it, or should I play it safe and take it to a suspension shop? I am confident I can do the work as long as there are no special tools/parts needed.

-Rick

If you have NEVER serviced a rear shock yourself, then I would advise against it...Some parts if you screw them up, you are out big bucks...and do you happen to have valve stack shims laying around....I think it's best that you send it to a professional !

[Wooded]

Thanks for your reply. I am thinking scenario #2 is the likely one. Would it be possible to take the shock apart myself and re-shim it, or should I play it safe and take it to a suspension shop? I am confident I can do the work as long as there are no special tools/parts needed.

-Rick

Taking apart a shock for a newby is risky enough. I'm not saying it can't be done or shouldn't... Just saying a regular rebuild is hard enough for a newby let alone trying to diagnose the problem. And yes you will need a few special tools and a video or some very thorough intructions.

[Ricktc]

OK well maybe I'll just look into buying a new shock, or finding someone locally who can take it apart and get the parts to fix it. Can anybody give me the instructions or a guideline on how to take it apart, I don't think it can be that hard with a basic guideline at least. I have access to basically ANY automotive tools I need, would that work?

-Rick

[Critter81]

I know this sounds kind of fishy but did you tighten your chain latley a chain that is too tight can bind up your suspension a mid stroke. The chain gets tighter as your suspension compresses. Check the chain first, then check the bearings both swing arm bearings and linkage bearing if those are all OK then it is in your shock. Send the shock off and get it rebuilt I recommend

GMD computrack

404-297-8464

Kent has been doing my stuff in my AMA bikes for years now

[Ricktc]

Yep I checked the chain, when it hits the really stiff spot the chain still has plenty of slack. That's originally what it felt like so it was the first thing I checked. What do you guys figure it'd be worth to send it to a suspension place and have it rebuilt, parts and labour?

-Rick

[huffster]

A rebuild, complete with parts and labor, should not be much more than $ 200.00 USD....Rebuilds are usually around $ 175.00 + parts. Shipping is extra.