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SUSPENSION QUESTION: Honda CRF250X - What sag measurements do you run?

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What sag measurements do you use on your CRF250X.  I am 160 lb.s with out gear.  I mainly trail ride, but will try out a few tracks this Summer.  Right now I have:

33-34 mm. - Free sag

100 mm.    - Race sag

Any tips or suggestions would be greatly appreciated.  Thanks!

250 on trail.JPG

Edited by Ben Sparenberg
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4.7 inches is a little much from what is considered standard, but i myself like a little more rather than less in the rear.

If you want the ultimate experience, take it to a suspension shop.  You won't believe what you get back. 

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Thanks for the reply.  What would be considered standard?  Do you measure from unweighted to weighted with rider?  I don't think I need to take it to a shop.  I haven't even started adjusting any of the settings yet.  I just want to get the sag right first.

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Two sag values; MX and offroad. Dwight Ruder has posted sag values for off road, he probably got or developed that data from being a factory ISDE rider for Honda.

  • …………,,,,…........ FRONT......... REAR
  • MX Static Sag..... 5- 10%........ 8- 11%
  • MX Rider Sag..... 25- 30%...... 28-31%
  • Dwight Static........ 14%.......... 11%
  • Dwight Rider……... 25……..… 33-34%

As you can see there are differences between MX and offroad.

Actual sag will be the above percentages time your front/rear suspension travel. For a 250X offroad sag values that would be:

  • Front static: 44mm
  • front rider: 79mm
  • Rear static: 35mm
  • Rear rider: 102-106mm

Static sag is wo a rider, rider sag is with a rider in the normal riding position. Another problem with sag measurements is stiction in the suspension so I measure each two times; once with the suspension rebounding and once releasing extended suspension, and then average the two.  So I compress the suspension a bit and let it rebound to a measurement, and then extend the suspension a bit and let it compress to a value. Two things will help with sag measurements and calculations: 1) Work with metric because all of the arithmetic is easier without fractions. 2) Buy a Slacker Motool Sag Scale, it allows doing sag measement with out needing a helper. It clips to the bike and magnetically to a axle, and has a remote display for the handlebars. Very cool. 

SLACKER-2T.jpg?1490087775

 

Edited by Chuck.
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What is confusing, is that I've read the CRF250X is factory sprung for a 160 lb. rider, which I am, with my measurements, how do I decrease free sag (-20 mm.) and increase rider sag (+35 mm.).  If I were to decrease the free sag, I would tighten the preload.  If I were to increase the rider sag, I would loosen the preload.  I can't do both.  The stock shock spring should be the right one for my weight.  Should I just go with rider sag, and loosen the preload until it gets to 100 mm. ?  

Nevermind.  One of my figures was wrong. 

Edited by Ben Sparenberg
rewording

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I just set my static sag at 33-34 mm., so according to my figures, my rider sag should be right at 100 mm.  I will know better when I get someone to help me.  I bought the bike used, but it was only used 2 seasons since new.  The original owner injured his back and said the bike had about a 100 hours on it.  He is my size and everything is stock.   

Edited by Ben Sparenberg
rewording

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17 hours ago, Ben Sparenberg said:

I hope someone can help me. I weigh 160 lb.s without gear. My bike is a 2013 Honda CRF250X. My preload on the rear shock is 2/3 up the threading. My settings on the forks and shock are at factory preset. Here is what I measured:

641 mm. - unweighted rear tire
587 mm. - rear tire under bike weight only
520 mm. - bike with geared up ride

54 mm. - static sag
67 mm. - rider sag

I know the X model Enduro is sprung softer for trail riding, but do these figures sound right? Thank you for any help.

250 on trail.JPG

You are not calculate correctly your race sag ( rider sag)

Race sag = unweighted rear tire (641 mm) - bike with geared up ride (520 mm) = 121 mm 

Your free sag is 54mm

You need to put more preload on your spring and set the Race sag to 105mm (starting point).  If you have the stock gray spring, your free sag should be 30mm +-5mm.

Like Chuck said,  take care about the ''stiction zone''. See the link for more infos.

http://www.racetech.com/page/title/Sag

 

Edited by TiJean
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3 hours ago, TiJean said:

You are not calculate correctly your race sag ( rider sag)

Race sag = unweighted rear tire (641 mm) - bike with geared up ride (520 mm) = 121 mm 

Your free sag is 54mm

You need to put more preload on your spring and set the Race sag to 105mm (starting point).  If you have the stock gray spring, your free sag should be 30mm +-5mm.

Like Chuck said,  take care about the ''stiction zone''. See the link for more infos.

http://www.racetech.com/page/title/Sag

 

Spot on, TiJean. Racetech, or Factory Connection. Don't totally discount having your stuff done by some one. My current ride is the 2nd one that FC has done for me . Big $$, but worth it. Whatever you do, don't over estimate your ability, especially for the woods, as it will end up stiff. Good for WFO, or Caleb Russell, but not for a mere mortal like me. Ok for the track, NG in the woods. Had to get FC to "plush" my front. Very, very happy now.

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I'm 170lbs wet and I have stock springs in my X, and they are too stiff for the terrain that I usually ride, so I may go down to .40kg springs. My forks have also had several serious revalves.  I have a light weight XR200 with Showa 37 USD forks (CRF150R) w Gold Valves and they are plusher in the woods than the X. I've been a bit reluctant to change springs because I really like the X for faster speed trails. When my buddy calls and says he wants to ride his special trails I leave the X in the garage.:banghead:

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Is there an idiots guide to setting the sag? I was asked by a club member if I did that used but new to me crf250x I stood there like a dumbass and said what is that? Still don't fully understand. Can you back up a bit and explain this to me and how to begin? I'm 180 lbs and 5-7.

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Checking  suspension sag is important whether you have stock or modified suspension and will help determine the spring rates for your riding weight and optimize the bikes ride height.  I strongly suggest keeping notes on everything you do and measure on the bike, and record riding results; use a spiral bound notebook, a three ring binder, or word processing SW like MS Word.

There are two sag measurements: static sag and rider or race sag. Here are the definitions:

  • Static sag is the amount of suspension compression from the weight of the bike.
  • Rider sag is the amount of suspension compression with the rider on the bike.

Two schools fro sag values; MX and offroad. I ride off road and use Dwight Rudders suggested values (he use to ride for the Honda factory team and is a ISDE medal winner). 

                        FRONT             REAR
MX Static Sag     5- 10%           8-11%
MX Rider Sag     25-30%           28-31%
Dwight Static      14%               11%
Dwight Rider       25%             33-34%

Front Static Sag should be 14% of travel; Front Rider Sag should be 25% of travel.
Rear Static Sag should be 11% of travel; Rear Rider Sag should be between 33-34% of travel.  

Measuring sag

The important thing on measuring sag is to pick measure points and have a repeatable method of measurements.  I use the top of each axle or axle nut and a feature on the frame. So pick a reference point on the front and rear that will be easy for a helper to use when measuring to the axle. My wife is my helper and I use a brake hose guide on the front and a seat mount boss on the rear, plus a tape that is easy for her to use and read. I recommend a metric tape measure to avoid working with fractions, avail at big box hardware stores. Put the bike on a stand and have your helper measure the distance from each axle to its reference point. Record. Drop the bike off the stand.

Push each end down an inch and allow the spring to push the bike back up, have your helper measure and record.

Lift each end of the bike an inch and allow it to settle, measure and record. Average the two measurements from each end and subtract from the fully extended measurements; this is static sag. The reason to do two measurements on each end is because of stiction in the suspension, this averages the two measurements from up stiction and down stiction to yield true sag.

Now the hard part: I do the riding sag in a standing position because I stand when encountering rough terrain. I place the bike next to a wall that I can easily touch to keep the bike vertical. My helper then repeats the process for static sag while I stand in a riding position and keep the bike vertical. Do the arithmetic again and you have riding sag.

The easy way is to buy a MotoTool digital Sag scale, it magnetically attaches to the bike and has a measuring string with a hook, plus a digital remote to display the numbers.  Fast, easy, and no helper needed; about $100 on Amazon.

Now the hardest part; deciding what to do with the numbers.  Any adjustments in spring preload will change both static and rider sag.  For fork springs I use 1” PVC tubing that I cut with a trim saw for square ends.  The rear shock spring has an adjustment nut but sometimes it is difficult to turn.  I spray dry lube with Teflon on the threads and the spring collars.  First step is to loosen the jam nut; I use a long drift and a hammer to knock the jam nut loose. One method to turn the adjusting nut is to grip the spring with two hands and turn it; sometimes the nut will turn with the spring.  Second is to use a spring nut spanner wrench.  Progressive Suspension calls theirs a Spring Preload Wrench. I use a Motion Pro #08-0029  “Honda Shock Spanner Wrench”.  http://www.motionpro.com/images/items/08-0029.jpg But I had to use a grinder to remove metal from the outside of the arch so the spanner would fit between the air box and the shock.  The other option is to remove the shock. 

If rider sag is less than spec with the correct static sag, your spring is probably too stiff for your riding weight. If rider sag is more than spec with the correct static sag, your spring is probably too soft for your riding weight. I used the word “probably” in the previous two sentences because static and rider sag each have a range of values making determining spring rates somewhat subjective.

 

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This will become very very simple if someone actually reads the owners manual. Honda has a very easy to read and understand susp adjustment section there, why folks seem deathly afraid to read the manual blows my mind. And I have found much better success with the FREE Honda info than I have with $$$ spent on "guru" susp guys lately. READ the manual. Read the manual. Read the manual. Just plain silly not to.

Edited by YHGEORGE
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