125-200cc Dwight was Right! Wr-125-144 Suspension

Static sag is OK on front but rider sag is Way off. Go to .38kg spring. You might try spraying your forks with Silicone spray to reduce stiction and remeasure. Be sure to bleed your air out when sitting on bike, before measuring.


Rear is close, real close. Go to 107-108mm rider sag and see how your static sag is. I bet you are good.

While I agree with Dwight's general theory, this:

... is wrong. Unless you've preloaded the spring to the point of zero rider sag, preload has no affect on ride harshness - only ride height (and, if you want to be picky, it will lift the bike into the softer, initial linkage ratio).

If a straight rate spring has 1mm of preload or 100mm of preload is irrelevant provided it there is still some sag present.

Let's say you've got two 100lb/in springs sitting on a bench (imperial units because they're easy). One has zero preload, the other has 400lbs on it (giving 4" of preload). To compress either spring another 1", will require 100lb of force. The preload does nothing to change the rate of the spring.

The other way of looking at it, is the luxury cars typically run very long, very soft springs with lots of preload to gain an acceptable ride height. They are not generally known for harsh suspension...

And while I'm digging up old posts, johnnyboy's comment about the rates of the top riders:
Spring rates are determined by the weight they bear (rider + bike) and rider preference. Rider speed and bike usage are almost irrelevant - if you had an adventure bike that weighed 100kg you'd run very similar rate springs as you'd put in a 100kg MX bike.
As you get faster, you need/want more compression damping.

Most bikes come with springs that are too soft and too much compression damping for most riders. This set-up works very well light, fast guys (think about the profile of the typical magazine test rider, particularly for competition dirt bikes ) while being acceptable for virtually everyone else. Most of us weigh more (requiring stiffer springs) and are slower (requiring less comp damping).

But,where your thinking is wrong is that a spring with 1mm preload and one with 100mm preload, it will take a harder load or impact to move the suspenion with 100mm preload vs that with 1mm. You are right that preload will not change spring rate only how quickly it will respond. Too much preload will make it harder to respond but yet when it does respond it will still bottom out. So I am correct in that less preload will respond faster to impacts with roots and rocks. It is easily tested to see if I am right.
I fully agree with your statement about rear suspension. But I find that many front forks are currently over sprung and will not give the rider enough static and rider sag to turn properly. The bike won't even turn without a berm on many MX bikes. AND or the rider has to crank in too much rear preload to try and transfer more weight to the front to get the front to bite and turn. This gives a harsh ride all the way around. But many MXers run their bikes this way so they can attack deep whoops faster but then rely on berms to turn. The bike then has a much taller static sag making it harder to throw a leg across.

The light spring will begin to stack in the latter portion of the travel instead of being smooth and progressive. The too heavy spring with not enough preload will not gain resistance as soon as needed. That's the whole point of getting both sag numbers correct and that can only be done with the correct spring. (unless the rider prefers an unusual set up)

a few noobie question.

On a 2012 WR125, does the rear spring have a rate stamped on it, or go by certain colors to determine what the rate is? I may need to go one higher but I have no clue what oem spring rate is.

Also for those who have tunning experience; I weigh 154 lbs without gear. With riding gear and tool/hydration, I have 100mm rider sag and only 19-20 static.

Would getting a stiffer rear spring to bump the static to 35mm make that much of a handling improvement in technical trails with rocks and roots?

I have not measured the front...figured it wont make sense to untill I have my rear set correctly with the right spring.

Thanks in advance for any input.

According to the parts listing on page 15 the front springs are 4.2 https://www.halls-cycles.com/Catalog/PDF/Husqvarna .PDFs/2012/WR-CR 125 29-07-2011.pdf The rear spring rate is not labeled. My WR250 had a 5.4 in it and I went to a longer than stock 5.6 and got the numbers just right for me (215 lbs no gear) I'm betting the 125s come sprung for a 140 lbs rider. I think mine had a sticker on in but it was a while back so it's hard to remember. Have you tried backing some of the preload out of the rear spring yet?

I believe mine had a 5.4 stock and I would be surprised if they have changed that since 09.

Stock rear on the 2011/12 is 5.0kg. Way too soft for me at 185lb. I first tried a 5.4kg and finally went to a 6.0. Big improvement. Also a .40kg spring in front with 5 weight fork oil.

I will back off on the preload some and see what free sag I get at 105 race sag. Hopefully I can get to 25mm with whatever spring the bike came with.

It sounds like getting an accurate oem spring rate from the dealer or Husky website is classified information lol....I guess the best way is pull it out and measure it myself.

Thanks guys I appreciate your help

No way will you get the sags right with the spring you have. You will need to go to a 5.6kg at least. Down on fork spring. Stock is a.42kg . You will need about a .38kg.

With a race sag around 110 I should be above 25mm free with whatever spring rate is on my bike now. Anyway, I will do some measurements sometime this week and report back. Hopefully I won't have to take a guess at what's on the bike now and just buy a 5.6kg spring.

Bleed the forks while sitting on the bike? I always bleed them on the stand with no load on the forks.

Do you ride the bike while it is on the stand ??? Forks heat up and air expands.

Take a deep breath and relax Sparky. NO, I dont ride the bike while it's on the stand. However, I do bleed the forks while the bike is on the stand because I DO NOT want the forks partially compressed before tightening back the screw.

Why not ? Air pressure will equalize in a very short time when heated. Unless you are having a bottoming problem that you trying to compensate for. If that is reason just raise oil level a bit. Your forks need no positive air pressure in them to work correctly. Once you are sitting on bike then you have positive air pressure bleeding them your way. Less air pressure equals a more responsive fork action.

Back in the early 80's, I would bleed my Husqvarna XC250 forks (and XC125) while the bike was still tied down. I still bleed my Current Husky fork after I have tied it down to relieve pressure on seals. Seems to work as I haven't had a seal leak. I have speed bleeders on my forks and highly recommend them. Even doing this before an event , you will find you have built up pressure before half the race is done.

Ok...I will try your method after my next ride although I will probably not feel any difference.

BTW, I decreased my preload a bit and was able to increase my free sag from 19 to 28 with a 108 race sag (I weigh 177 lbs with full gear, hydration pack, and tools). It's close enough for now untill I figure out what spring rate came with the 2012 wr125. Or I might just send the forks and shock to Factory Connections....they did a great job with my crf250r suspension.

Which fast bleeders do you use, and do they need a cap to keep the dirt off?

I believe the speed bleeders were the same for WP KTM forks.