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2002 cr250 stock shock spring.
Finished restoring this bike and noticed the rear end is sitting lower than before. How do I raise the rear height adjusting the shock pre-load? Is it by tightening the adjusting ring (compressing it more) or loosening it (and letting the shock become longer) ? This will save me a little time and effort.
In my mind loosening the adjusting ring and letting the shock become longer will raise the rear end, but then again my first guess is usually always wrong.
2002 cr250 stock shock
Tighten the adjusting ring will decrease free sag, but you also need to check race sag and spring length...
Thank you! When you say tightening the ring will decrease free sag does that mean it would raise the rear end? I just want to bring it up to the ballpark I know it should be at before making all the measurements of the different sag. The reason I think I need to loosen the adjustment ring is the stock length is calling out 10.43" but right now I'm right at 10" (which is what it was when I got the bike) I'm thinking I need to loosen the shock out to that standard length and it would raise the rear to where I need or at least be in the ballpark
Also, my 2002-2003 SERVICE manual does not include all of this information. Is this from a separate manual like the owners manual or something? Any idea where I could get that download?
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Spring length is covered in the service manual, page 12-23, free sag and race sag are covered in the owners manual...
https://www.manualslib.com/manual/706239/Honda-Cr250r.html?page=102#manual
Thank you for that!!
So just again, when you say tightening the adjusting ring will "decrease free sag" that ultimately would result in the rear end squatting more?
Free sag is the difference between the suspension fully extended and compressed under the bike weight, if you tighten the adjusting ring, the suspension will compress less under the bike's own weight, so the seat/rear fender will be higher.
Free sag should be the last thing you measure, you should tighten the adjusting ring until the spring length is 265mm long, then adjust race sag with the rider on the bike, 90mm if you want a fast turning bike, 110mm if you want straight line stability, or somewhere in-between, then measure free sag to determine if the spring rate is correct.
Gotcha. Thank you for explaining it. What worries me is I tightened the spring down to 10" and locked it and put it in the bike. Adjusting it out to 265mm (10.43") would just have it sagging more. At least I know which direction to go to figure out if it's even the correct spring rate. It was a stock yellow spring though so I would think I could make it work. I'm 190 lbs on a virtually stock 2002 cr250.
The OEM springs are all yellow, there will be a color painted on the spring near the end...
that designates the spring rate...
Racetech has a tool to calculate a recommended spring rate...
https://racetech.com/product-search/
Thank you for the info! I looked for markings on mine before I took it to powdercoat and there weren't any anywhere, so that makes me feel like its the stock spring.
I was also worried about shock orientation when putting it back on but noted that the smaller coil one the end was facing up and the fatter coil (like the one in your picture) was facing down
What do you mean by smaller coil end and fatter coil end?
That picture you posted above. The very end of the coil. On one end of the shock that coil is larger and the other end is thinner. It was the only thing I noticed about the shock to note which direction was up when re-installing (if it even matters)
Sag is adjusted with spring preload/rate. Ride Height is adjusted with HS compression.
🤔
If its a stock 265 mm spring buddy, the pre load is 15 mm, and 1 full turn of the shock nut is approx 1.5 mm
copied from my showa supplier if it helps
Showa 50 mm ID
Nitrogen Pressure 142 psi
Shock Length (Eye to Eye) 488 mm
Shock Travel 134.5 mm
Shock Shaft Outer Diameter 16 mm
Standard Sag 100 mm
Shaft Nut Torque 25 ft-lbs (34 NM)
Shock Oil 5 Weight
Standard Preload 15 mm
Well that certainly changes things...
The Service Manual says the shock length installed should be 265mm (10.43") I was under the assumption that this was what it should measure pre-loaded/tight. If it is indeed a 265mm spring and needs 10 revolutions of the adjuster nut to achieve 15mm that could definitely change things. I could make a mark with a sharpie on the outside of the adjuster nut and just count 10 revolutions and that get me in the ball park.
I'm going to pull the shock this weekend and verify that it is a 265mm length and then make the correct pre load.
Thank you!
So just as an update I measured the free sag of the bike on my lunch break (I know I'm supposed to do this last but just as a reference)
and I'm at 2.625" / 67mm of Free Sag.
The spec limit is 0.4 - 1" / 10-25mm
So I'm about 1.6" / 40mm over the spec limit. Seems like the shock spring definitely needs to be tightened down more.
You set the race sag first. Then you check free sag to make sure you spring is in range. If it's not you have issues.
Ride the bike and adjust HS comp to control how high in the stroke it rides/ride height.
So guys just to update I had the rear shock rebuilt. The guy said the oil had basically turned to foam after all this time, so much needed. He went ahead and set the pre-load in a general setting.
I got my race sag number saturday which is right at 106mm, so I'm thinking a couple more full revolutions of pre load adjustment will get me right at 100mm.
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