2010 YZ450f Sag

[95s10nj]

I've searched the forum and found a bunch of different opinions on where exactly the sag measurements shall be taking and whether to be sitting or standing. I borrowed a motion pro uni-sag tool from a riding buddy to check my sag this weekend and that tool goes from the rear axle to the seat bolt which is on a decent angle. I was told by a buddy that race tech told him that there was about a 10mm correction error because of the angle. Seems to me that this may be somewhat true but I think its hard to generalize 10mm when different bikes have different mounting point relationships. Should I be measuring vertically? So before making adjustments, my race sag was 80mm and the static was 20mm. After several turns to loosen up the spring, my race sag was at 92mm with a static of 33. The race sag was measured with me in street clothes with riding boots(didn't think it was necessary to put on riding pants and helmet in the driveway lol) sitting in attack position. Should I keep loosening up the spring till I get to 100mm of race sag or should I have someone help me measure the sag so that it can be measured vertically with me standing on the pegs?

[grayracer513]

You should get help, and here's why.

First, the whole thing with vertical vs. angled measurement. If you can get the exact angle at which the tool is inclined, then through some simple trig you can discover exactly what the correction should be. Otherwise, it's a guess.

Secondly, unless you really sneak up on it, the suspension will compress beyond the true sag number when you mount up, then rebound a bit. The tool then gets set at a greater than actual amount of sag. I know one gentleman who tried the MP tool 5 times without changing anything and got 5 different readings.

And lastly, the only way that the readings are going top be 100% comparable is if you take them while standing on the pegs, hands off. Otherwise, it's simply not possible to repeat the exact position you were in or how much weight was distributed where.

[95s10nj]

You should get help, and here's why.

First, the whole thing with vertical vs. angled measurement. If you can get the exact angle at which the tool is inclined, then through some simple trig you can discover exactly what the correction should be. Otherwise, it's a guess.

Secondly, unless you really sneak up on it, the suspension will compress beyond the true sag number when you mount up, then rebound a bit. The tool then gets set at a greater than actual amount of sag. I know one gentleman who tried the MP tool 5 times without changing anything and got 5 different readings.

And lastly, the only way that the readings are going top be 100% comparable is if you take them while standing on the pegs, hands off. Otherwise, it's simply not possible to repeat the exact position you were in or how much weight was distributed where.

Surprisingly the measuremnts were very consistent and all within 1 mm range and I tried my hardest to get on very lightly without overly compressing the suspension. Trying to get off the bike without compressing the suspension any further was very hard and it probably made the numbers inaccurate as i probably compressed the suspension past the true sag number. I'll grab a buddy and just use a tape measure and hopefully I can get to 100mm without having the static above 40mm.

[grayracer513]

You wouldn't want it to be less than perhaps 15, either, preferably 20.

[YamaLink]

I'd get a buddy to help, and make sure he/she knows to measure from the same Starting Point A and the same Finish Point B that you used to measure the bike while on the stand. And also use the same side of the tape measure (seen it done wrong many times).

[95s10nj]

Well I got the wifey to help me today and currently I have 102mm race sag and 45 static. I wanted to get the race sag set at about 105 but stopped at 102 since my static is already too high. How many rates softer should I go on the spring? One of the local tuners recommended a 5.3 or 5.4 for my weight of 160 since he has another 2010 out there with a 5.3 with a 160 pound rider. What do you guys think? I'm thinking maybe a 5.5...

[95s10nj]

any recommendations?

[CaptainKnobby]

I would just get the next size down. I kept the stock spring on mine and i weigh 175lbs. Of course I also have the Dell-Taco kit in mine which works ausome.

[a450]

I know everyone says to run around 100mm sag but I encourage you to try around 115mm to 120mm. I say this because the 2010 yz450f's run a little bit higher in the rear by running around 120mm sag you lower the rear end and make the bike more predictable. It took my mechanic and I several weeks of testing to figure this out but I'm very happy with how the bike handles and the plushness of the suspension. I am a 150lb. pro rider and have changed the springs according to my weight. (all of the above measurements are race sag of coarse)

Edited August 17, 2010 by a450

[tech24]

I'm running 110 with stock spring and the bike handles like a dream but I haven't played around with it much

[MXR176]

107mm with Ride Engineering Linkage.

[95s10nj]

I ordered an Eibach 5.5kg shock spring last night and i'm going to drop the bike off to KB5 Suspension in PA in a few weeks for a revalve...Right now my race sag is 102 and i feel as if it needs to be run a little higher to make it a little more stable in the high speed sections. The bike handles great on a freshly groomed tracked but it beats the hell out of me when its starts getting choppy.

[McFly529]

Hey Guys, Hope your not having too much trouble w/the Uni-Sag tool. Most manuals tell you to measure to the seat/fender bolt, that's why the tool uses that connection. When you sit on the seat for sag check, find your sweet spot, reach back and make sure the marker is pushed down, put your hands back on the bars. Then quickly pick your feet up, then back down. If you are on any decent surface, readings will be consistent. Hope that helps. I am real familar with the tool. I invented it.