125-200cc Spring Rates? '06 WR125

Hey guys,

Can anyone give me some input on spring rates for my '06 WR125? Right now its stock suspension, probably never been serviced.

My data:

• casual "fast C" or "slow B" level trail rider. No MX at all.
• 205-210 lbs
• 6'6"
• 53 yrs old

I would like to mod the suspension to be able to soak up trail junk, but not too soft as to be mushy, or let the bike wallow. Not concerned about landing huge jumps, never do that stuff.

I read Kelly's write up on his Gold Valve mod to his '04 125 forks and I will likely do that sometime this winter. But for now I'd like to get some new springs on it pronto.

Read so many suspension threads on here my head is swimming.

Race Tech's suggested spring rates:

Ft: .435 = .43?

Rr: 5.985 = 6.0?

Do those rates sound right?

Anyone else around my weight/riding level have any experience?

Thanks,

Ed

Ps: Please have patience with all of my posts and questions. Husky's are completely new to me so I'm on a steep learning curve. KTM's yeah, I got that down pretty good. Husky's, not so much. Yet. Thanks!

Same weight, I run 4.6 front , 5.6 rear. If you can swing it get the Gold valves or the riders edge valves. Stock those forks are some of the worst

What exactly is the gold valve and the riders edge valve? Are they both a valve .

Kelly, are those "Progressive" brand springs? Or Race Tech springs that are progressively wound? Thanks!

Not to disagree with Kelly, but I have run progressive springs on other bikes (not my WR) and was quite dissatisfied with them. I felt like they rode lower in the stroke because the initial rate was too soft, and then firmed up too much and became harsh.

Plus, you already have tunable progression via the oil level, so I don't see the reason to also run progressive springs.

Both the RaceTech valves and the Rider's Edge valves replace the stock base valve bodies. The main difference is that the ports are quite a bit larger. On some bikes this is of questionable benefit, but I think your bike may have the Marzocchi 45s, which have comically small ports.

Rather than spend a bunch of money on aftermarket valves, I take the stock Marz base valve bodies and drill out the compression side ports, and then revalve them to whatever your desired flavor is. It's a little bit more DIY but also a lot cheaper. If you're not comfortable with that, both the rider's edge and the racetech valves are a good option.

I take the stock Marz base valve bodies and drill out the compression side ports

Any pics of this?

Yup!



In that picture I have only done 1 of them, just so you can see the difference. Of course, you want to drill all 4. I think I drill them to about 4mm in diameter (0.15 inches), but you'll want to measure the inside of the shim seat to be sure.

The ports turn about 45 degrees and exit on the side, so you need to drill from the top (shown above) and also drill from the side.

It's not "difficult," but the valve is fairly hard steel so you need to be careful to clamp it down, lubricate the bit well, and be patient. After you're done drilling, you want to clean up the shim seating surface to make sure they will still sit flat and seal; you could run a nice flat stone over them, or sandpaper on a surface table, or lightly chamfer the inside by hand (I do this).

Also, make sure you do a super good job of cleaning all the chips out when you're done!

After you drill them out like this, the ports are bigger than the ports on the newer KYB forks, so they ought to flow plenty. The ReStackor program also says that they will be a flow restriction on the stock forks, but shouldn't be when drilled out.

One comment: Marzocchi knows a lot about suspension, so we ought to keep in mind that they had some justification for designing them this way. A lot (all?) of the Shiver 45s don't run midvalves, so the small ports might have been some attempt at adding some highspeed damping, for example. In any case, I think drilling them out is a sound technique, just be aware that if you drill them out and don't change anything else on the forks, the fork performance may change. Whether or not this is a good thing depends on the rider, the bike, and how you intend to use it.

Thanks, great explanation, I may try this next.

Hey Kyle, thanks for the input, this is very interesting as I'm looking to economize wherever I can. And yes, my bike has the Marzocchi 45's.

Question: for the Marzocchi 45's that you've done, have you done any other mods for woods riding, like changed the shim stack?

If so, could you tell me more about that?

I grew up in NJ and have spent time in the woods of PA. The terrain is actually fairly similar to what I ride out here, except we have much higher mountains. So settings that work for you guys out there would probably be fairly close for us out here too (with the usual caveats of rider preference, skill level, type of riding etc).

I'm obviously not a suspension tuner and don't have the time nor knowledge to apply to making too many changes at once.

If you've noticed improvements with just the drilling out of the ports, and everything (save oil level adjustments and spring changes) remains the same, that would be huge in my book.

Additionally, if I was unhappy with the results of drilling out the stock components, I could always just buy the after market valves and I wouldn't be out anything but some time.

On the other hand, experimenting with shim stacks would probably not be a good idea for me, I could see myself screwing that up royally. Lol!

Anyway, thanks again for the input, and if you have any input on any other mods you have done to the Zook 45's for woods riding, I'd love to hear it. -Ed

Hey Kelly, thanks for posting all this great info! I think you've convinced me to go with those custom progressive springs from Richard.

They sound like the cats meow.

And people should know that I've known Kelly for some time now. And although we've only been on a few rides together, I know that he knows me as a rider pretty well and same for me about him. He knows what I like to ride, what my pace is (freakin slow!), and what my mechanical abilities are. I even bought a bike from him, a YZ250 smoker. He said I would love it. Bought it without even test riding it. Surprise! I loved it!

So I feel very comfortable with his recommendations around what I'm looking for.

And of course suggestions from anyone else is greatly appreciated too, that is why I posted here on the forum, was hoping to get input like I've been getting from some different peeps. -Ed

Buddy Mike recently rode my bike, immediately put his KX250 up for sale, bought an 04 CR125 and proceeded to copy my bike suspension and all. He is super sensitive to setup and is super finicky about suspension and setup. he asked me to let him know exactly what I did to my suspension so he could duplicate it.

The above is a true statement. I hate progressive springs for motocross, but for the type of technical, tight, rocky singltrack I ride now they worked awesome. This in conjunction with the gold valves and Kelly's magic potion in his forks, added up to one of the best fork setups I have ridden with in 40 years of riding. I really never thought Marzocchis could be that good. I liked the whole package well enough to proceed to ride his bike for at least 30 miles of our 60 mile day. I NEVER like someone else's bike enough to ride it more than a mile at most.

BTW- Kelly I need your oil weight and level from your setup sheets.

Yes, the drilling is only part of the modifications. I've done a few sets of the Shiver 45s, and all of them are running modified shim stacks.

The shim stacks I am running on my 610 are probably way stiffer than when you'd want on a 125, but I can share them too. My brother has a TE410, and we are running a much lighter shim stack on that. On both of those bikes, we've added a functional midvalve in addition to the base valve changes (midvalves on some/all Shiver 45s are just a checkplate in stock form), but I don't think that this is a necessity, especially not for a woods bike.

I'd be happy to share the stacks we are running, but I am not sure how relevant it is.

I haven't run that test. My suspicion would be that drilling the ports will help but changing the stack is also important.

If you're interested in running a test for the sake of science, I would love to drill your base valves and pop a modified shim stack on there. It would be cheap, and then if you didn't like it you could go to aftermarket valves without having sunk too much money. We can talk about it, but I don't think it would possibly be any more than 40-50 bucks with shipping.

I'm not trying to "get into the business" in any way, or take business away from the real guys, but I do love to try DIY stuff and am always looking for volunteers (victims?) to test things out. Gaining (and sharing) knowledge is how we all get better/faster.

I hear you bro! I was just thinking "who has a nice drill press, clamps, and know how around here to help me with this..."

Trav was my first thought, then I remembered Tyler's recent party. He has a killer mini machine shop setup down at his new place. Its awesome, drill presses, lathes, all kinds of grinding and cutting tools, welding equipment, huge welding table, vises, clamps, anvils, huge bike lift (or two), all in a nice big, clean, well lit work space. I had no idea.

He also has a sweet 80's stereo and a full sized fridge set up as a kegorator. When I saw it I was ready to move right in.

The real issue here is funds. I have a very limited budget and many mods I want to do to the bike to set it up. Can't afford to do all of them at once. Suspension, lower pegs, tall bars, steering stabilizer, rad guards, 12t sprocket, brake pads, jetting, a Lectron or SmartCarb. Then the WB165 kit. Adds up quick.

Anyway, I think you are correct and the aftermarket valves are in my future, but at the same time I do love the idea of experimenting and seeing what happens, its part of the fun.

Kyle, that is a very interesting proposition. Thank you for offering. Let me give it some thought.

My only reluctance would be to sideline my bike for a week or two while the parts shipped back and forth. Not a big deal really, but with my family schedule, I often don't get to "plan" rides, they more often happen spur of the moment when the stars align.

Anyway, thanks! Let me mull this over. -Ed