Dialing in 00 yz 125

[JJmxr]

I just bought a 00 yz 125 for my 13 yo. He just made the jump from his 80 and I could use some advice. My biggest issue is with the spring rate. the stock rate is a bit stiff for his 130lbs, but I am hesitant to re spring when he will just be getting bigger and faster before I know it. Being new to this bike I was hoping to get some advice on where to start as far as settings. Is there a sag or clicker setting that might help offset the too heavy springs. Since we are new to the high speed circuts maybe a quick lesson on what they do. He was finishing top 5 on his 80, but I would rate his skill as novice. We do motocross, and some of the tracks have some SX stuff mixed in. Thanks alot.

 

[JTT]

Unfortunately there is no compromise for the wrong springs. Fortunately your can buy springs and keep the old ones for when he gets heavier.

As far as settings, there is a good tuning guide on Jer's site (MX TECH). Set sag first and start with stock setting and work from there. Take care to record all changes and baseline, so that you can get back to them if need be. The high speed circuit is used to control movements where the shock movement is fast (as opposed to bike speed). This would include things like square edged bumps that force the suspension to compress over the least amount of time. Low speed, in contrast would be conditions like large rolling bumps.

Hope this helps some. Stick around here and you will learn lots...some pretty bright people hang out here (present company excluded) ;)

 

[kxyzdad]

JJmxr I also have a 130 Lb rider on a 2001 Yz125 . We have set sag and clickers, the bike is ok but I think it could handle better!! On starts the rear will not track straight !! Loosks like RC going through the whoops at Houston !! Is an after market spring the answer to this problem. I like JJmxr need to spend support money where in does the most good. Any help would be appreciated. Thanks JJmxr for using your post. I think were are looking for the same answers

KXYZDad ( MX Support Dad

 

[JJmxr]

I know there is no substitute for the right spring rate, and it is probley the most important place to start as far as tuning goes. I figure we are just one spring rate off ( 4.6, and .4 stock, and should probley be running 4.4, and .38) I guess I was just hoping to get some advice on a good baseline to tune off of. I admit though that my skills are weakest when it comes to Susp. tuning, and I don't think my kid has enough understanding of how the circuts work to give me good feedback. I do plan on using Jer's tuning guide when we go to the practice track next weekend, but it does not address the high speed circuts. One thing I know for sure though, this heavily modified 125 ( or 133 shall I say) flat out rips. Having only ridden 250's I was suprised how fast it was, and here I am putting my 13yo on it. I must be a bad Dad:p

 

[MXP1MP]

I weight 135 with my gear on and I didn't have any problems with my '02's spring rates. they are the same as the '01's and '00's. I really just started seriously racing mx about 6 months ago and I can bottom the forks and the shock on hard landings semi harshly. I race 125 beg (C class) My only complaint with the suspension stock was it didn't have that plush feel to it like my '01 CR had. I just had the suspension revalved to offer a plusher ride in the first half of the stroke and had the lower portion of the travel to be stiffer offering a plush/smooth/good resistance to bottoming. The stock spring rates were retained, I don' t know what was done to the valve shims on the cartridge but I have an idea. That it involed changing the stack up with softer shims then they used harder shims changing the sizes around. The oil level went from 135mm's stock to 110mm's comp 8 rebound 12 stock preload. The shock got a similar treatment in the valving stock oil level retained stock spring sag left at 100mm's using 7 weight oil. The shock's High speed was adjust to 1.5 turns of high speed compression 10 compression 12 on rebound. The bike noticably sags better to my wieght now and it handles so much nicer it was exactly what I asked for, I have much more confidence in the bike now TBT did a great job. It was about 300 to have it done but well worth it. But I know how it is being tight on cash, you can try going to softer springs but I feel that the forks will only suffer with softer springs the bottoming may become harsher. Just note that if you do go softer your gonna have to readjust the oil height maybe even end up with a higher wieght oil. Going softer on the shock if the sag is all ready dailed in would be a waste in a sense? Cause basically thats why you set the sag in the first place for your weight(at least thats how I see it) I'm not suggesting anything just brain storming here.

 

[JJmxr]

Thanks for the reply MXP. Even though I think you and my son are a bit light for the stock spring rates, I agree that a good re-valve will probley make things ok. We have yet to make it to the track ( Hopefully we'll make it to the ORV next weekend weather permiting) so I don't have any feedback yet. Although if you didn't think they were too harsh then it gives me hope my son will find them ok. He is also going to run the Beg. class also for a month or two until he gets used to a full sized bike, but I suspect that since he was always top 5 on his 80 that the Beg. class MAY be sandbagging before long. The susp. has some Pro-Circut work, but the previous owner was a top B class rider, so I'm thinking they are probley a bit stiff. You are right about the sag though, if when I set it( have not gotten around to it yet) I have 17- 25mm of unladen sag then I'm not going to worry about the springs. I'm glad you had good luck with TBT, but past experiance will have me steering clear of him, and going with Devol or PDS.