Suspension Setup recommendations.

I talked with Tom Watson since my last post http://watsonperformance.com/
They're still racing these bikes from the sound of it and he was happy to give some advise and an offer of more help too.
The basics he agreed with what we're doing here, get the rear close before judging the front. He also said he thought the stock spring could be ok for my weight, @ 160lbs w/o gear, and to not worry about static sag now, just get rider sag right. Well I weighted myself and I'm at only 152lbs, but will bulk up a few next. Also went to minimum preload on the shock, @ 5mm, and got sag of 46/91 when I want @ 35/108. That brought the front down a little and handling improved dramatically. Still can't bottom either end though, so installing that 5.0 spring on the rear next.

Steve, I have to agree. Bad forks mess up your hands and the chassis, but a bad shock will mess up your hands, the chassis and the forks! And sometimes your pants.

Setting up the suspension on my 2012 WR125.

Front sag was 31.75mm and 50mm with the factory springs. Cannot see what rate they are but they are OEM as I'm the first owner of this bike.
Installed Race Tech .38's tonight.
Front sag now is 38mm and 63mm.
Closer but still pretty far from optimal.
The new springs are shorter than the stockers and have almost no pre load on them when the caps are tightened on the rods.

Any ideas to get me closer to good numbers?

Thanks in advance.

Make a spacer and give them some more preload

Sorry if you already posted this, but have you checked fork/axle alignment to make sure it's not in a bind?
Also, did you replace the crummy stock oil? At what level? Strange about the spring length, sure they're the correct springs?
You should have gotten some 1mm spacers with the RT springs.
I just installed RT .40 springs in my wr300, stock preload and 5wt Maxima 120mm from top. Sag is currently 50/65, should be @ 42/75. When the .40 springs were new sag was 48/73 so I suggest riding it a couple of times, then remeasure.
And is your shock sag correct? Best advice is to do the shock first.

Didn't check fork/axle alignment last night as it was getting late, will do so tonight.
My bike only has 15 or so hours on it, so I figured I would leave the factory oil in the forks for now.
The spring length is only about 1/8" at most shorter than the stockers, so I'm betting they are the correct ones.
The spacers RT sent me do not appear to be correct, the diameter is much smaller than the spring diameter.
Adding spacers to get more sag seems counter intuitive, wouldn't that give me less?
The rear numbers are close, something like 35/96....

Thanks again for the help guys......

My bike had @ 10 hrs when I got it. PO over tightened everything, forks were over torqued and crooked. Saw one recommendation for 8 ft.lb. on the lower clamp bolts to reduce binding, but my forks got tweaked every time I crashed. Now I'm at @ 10 lower and 20 ft.lb. upper and no tweaking so far.
When I first serviced my forks I found what seemed to be different fluid in each leg. One side had darker, thicker "oil" than the other and also different amounts! Now I have the oil level at 120mm from the top of the tube with Maxima 5wt fork oil. The MotionPro fork oil syringe is only $25 and well worth it for fork tuning.
The preload spacers fit btwn the spring and the retainer at the top. The RT instructions have some pictures of different forks and one is accurate for us.
I don't think you need more preload now. I do think you need to flush your forks and add some good fork oil at the proper height, make sure of the alignment and torque, then ride a few times to break the springs in and re-measure. I have new springs front and rear and sag changed after each ride so far (should be consistent now though, I hope).
Your shock sag is close, so you should be able to get the front close too. Your sag numbers don't make sense, so probably some other factor throwing them off. How are you measuring? I use a re-usable cable tie on each leg.
Another good basic check for binding and fork action is to stand beside the bike holding it level and press on the peg with your foot. The suspension should compress evenly front and back. When my forks are tweaked they don't compress evenly with the shock. I also clean the fork tubes with spray silicone to reduce stiction.

Ok, after a few rides my sag numbers are now consistent. I installed a lightly used 5.0 shock spring from a WR125 (which actually had a test label on it) and a new set of RT .40 fork springs. Again, fork oil is Maxima 5wt @ 120mm from top/air space.
Rear sag is 40/95 with @ 9mm preload, fork sag is now 45/80. Ideal is 35/108 rear and 42/75 front. So pretty close, sounds like I need .48 rear spring and 1-2mm additional preload in the forks. The ride is plush now, forks dive under hard braking a little too much but not uncontrollable, huge improvement in turns, settles in and tracks well, no more desperate counter steering to hold the front end down.
I have deliberately slammed the rear end through some long, rocky ruts in 3rd and 4th gear. Under power the rear squats slightly and tracks straight through that and basically over, around or through everything so far. No kicking, bouncing or other nonsense at all, still a little loose in a couple flat, slippery turns in the woods, but totally predictable and I'm still fine tuning the clickers. Overall, really happy with the improvements.

On Sunday I did 3 hours WFO almost non-stop (the bike fell over twice! and @ 2hrs in I had to pee) and it was totally doable, fatigue didn't set in until I got home and climbed off the beast. If race longer than 2 hours I may need a diaper though

more later

ok im a newbie and am having trouble with my suspension. about 200 pounds plus gear.

txc250r

rear sag was 34mm Rider sag was 78mm
Front sag was 20mm rider sag was 34mm

took it into a suspension shop and they went down 2 springs in the front from .46 to .42 and revalved it front and rear.

it is now:

rear sag 30mm Rider sag 108mm Supposed to be rear sag 32mm Rider 101mm
Front Sag 32mm rider sag 51mm Supposed to be front sag 42mm Rider 75mm

so where to from here? im still a long way off the rider sag for the front and too much on the rear.

do I need to go to lighter springs in the front? and is the rear close enough to adjust it a bit?

Take sag numbers sitting and standing and check if any difference.

Rear sag at 30/108 is ok.

Could check how many mm preload spacers are in the front forks and remove to minimum.

Or add a little more preload to the shock for about 105mm sag and slide the forks up in the clamps a few mm to get a bit more weight on the front end.

Q for the quick studies on this thread; 2009 wr300; fork- stock spring .42[i think] 25/80mm and shock; stock spring 5.4[i think] 30/90mm. feels good. better would be better... suggestions?
thx

Note; dressed weight - 185 lbs.

Going to try to resurrect this old thread.

I just purchased a used 2008 WR250. Rode the bike for the first time and thought about selling it. My test ride was a very simple ride up and down a dirt road and the bike felt good. After a more extensive ride, I was thinking the bike might have been a mistake as it just feels too big. After doing some research I thought I had better at least give it a go to get the suspension set up for myself and my riding style, etc.

I took some measurements and ended up with the following:
Static front - 49.5mm (haven't taken rider sag measurements on the front yet as I moved on to the back so I could get that dialed in first)
Static rear - 45mm
Rider rear - 60mm

I made an adjustment to the rear spring and only netted 5mm more in sag to get to 65mm rider sag. I'm up towards the top of the threads (maybe 1/2" left), so I"m thinking maybe a lighter spring is in order as I don't believe I'll get near the 108mm recommended sag numbers. I didn't adjust it that far, maybe 2 full turns.

Looking for any advice I can gather.

David,
You didn't elaborate on the condition of the bike, the hours or your weight. I had an '09 and weigh 195 with no gear and I was able to get acceptable sag numbers with the stock springs. I think the best advice would be to make sure everything is in spec before you start swapping springs. Make sure all the linkage bearings are in good shape, etc etc. If it were mine, no matter the hours, I would take the forks apart. Mine came from the factory with assembly lube clogging the compression valving. Cleaning them out and changing the oil made a world of difference. I'd go ahead and change the bushings and seals while you have them apart.
All the info here with spring rates, race sag, rider sag, static sag will make your head spin. Maybe it's me but I can never duplicate sag measurements from one day to the next. It might be perfect at 105mm today, go ride it and it's 80mm the next day.

I've since moved on to a Beta 300RR and the difference is amazing.

Rob, thank you for the reply.

The bike is in good condition, however seeing as how I'm a new owner to the bike, I honestly can't speak to the condition of the swing arm bushings or fork internals. That's a good point and I will inspect and likely just replace all necessary parts, although I'm wondering if I should just sell it and get something else. I'm more of a trail rider vs. a track or mx rider, and while this bike has the wide ratio gear set, it's a lot different from the 4 strokes I'm used to riding.

As far as my weight, I weigh in at 170lbs. Since I don't have the budget to get a newer bike, virtually anything I get, I'm going to have to service. That being said, I appreciate your opinion.

Where is a goood source for parts for these bikes?

David,
Didn't mean to come across as a butt head saying to buy a new bike. I rode mine for a solid 6 years and would still be riding it except I broke my leg and sprained my ankle badly and needed an estart bike, I just couldn't deal with that kickstarter any longer.

Considering everything else out there you have one of the best woods bikes made. Check and see what carb is on it, hopefully the previous owner changed it to a Keihin, get that bike jetted right and you'll never ride a 4T again. I wish I had that motor in the Beta.

There's a lot of very knowledgeable folks that still keep an eye on this forum you'll be able to get plenty of help here.

As far as parts go try Gerald at Upstate Cycle in Greenville SC he still has a lot of parts on the shelf. Bill's Motorcycle Plus in Salem Oregon and Hall's Cycles in Springfield IL. They should be able to help you out.

No offense taken. I felt your response was absolutely appropriate. I did a little more adjusting and the suspension is feeling a little better to me. I'm mechanically inclined, so I have no issues with digging into what needs to be done to the bike to make sure it's in tip top shape.

It still has the original carb on it, but it seems to run very well. I know the Keihin carbs are a better carb. Can you give me some direction as to what carb to get (part number, etc.)? I'll research that as I haven't done that at all.

I appreciate the info on where to get parts as well!

There's a couple different versions of the keihin 36mm PWK you need the short body which has a rectangular top and two screws versus the long body which has a round screw on cap. I think I still have the brand new mikuni sitting in the keihin box, I'll look tomorrow and see if I can find the part number.

I don't think your weight is the main factor, the WRs are definitely a tall man's bike. I bought mine knowing that because I'm 6'6" tall and it fits me as does a newer yz450, most other bikes are too small for me. What is your height?

I'm 5'8". Factory specs indicate a 38" seat height, but this one measured 36 when I bought it. If I can get the sag closer to correct, it will be more comfortable to ride.