[djhurayt]

I just bought Vicki a new (carryover) 07 CRF230F. I am looking for the race sag numbers I should be starting at.

By the way, looks like a nice site for the CRFers

[RLPII]

Here is what another rider sent me when I asked the quesiton:
Rear sag

"Sag, sometimes called race sag, is the amount the suspension collapses when you're sitting on the bike compared to the fully extended suspension position when the bike is on a stand. Most bikes do well with about one-third of their rated suspension travel used as sag. For example, if your bike has 12" of travel, you'll want 4" of sag. This is a suggested value; you may decide you want more or less sag.

Place your bike on a stand so the rear wheel does not touch the ground. Measure from the rear axle to a point on the rear fender and write this number down; call it E for extended. On my 230F, I came up with 24 1/2" from the tang on the axle adjuster cam to the rear fender. Next, sit on the bike and have someone measure between the same two points and write this number down; call it C for compressed. On my 230F, I came up with 20 3/8" before adjustment; way too much sag.

Now, calculate E-C and call it sag.

Calculate the desired sag amount by dividing rear wheel travel shown in the Honda specifications by 3. For the 230F, it's 230mm / 3 = 77mm (9.1" / 3 = 3").

If sag is larger than desired sag, then you have too much sag, and you need to crank up the shock spring preload.

If sag is smaller than desired sag, then you don't have enough sag, and you need to remove some shock spring preload.

My sag was 4 1/8", which is 1 1/8" more than desired sag.

To adjust the shock spring preload, you can either remove the shock from the bike (difficult) or do the adjustment with the shock on the bike (preferred). To adjust the preload with the shock on the bike, do the following:



Two jam nuts on the top of the shock are screwed tight against the spring. These preload the spring and affect sag.

Use a drift or similar tool to loosen the top jam nut on the shock. Turn it counterclockwise, looking down from the top. Use a 3-5 pound sledge; a regular hammer leads to a mangled nut because of the repeated blows. After the upper nut is loose, run it up the shock body to get it out of the way. There will be one jam nut still tight against the top of the spring.

Remove the rear wheel mud-guard (2 screws). Pass your hands through the space left by the removed mud-guard and grip the spring. Turn the spring counterclockwise to loosen the remaining jam nut (decreases preload) or clockwise to tighten the nut (increases preload). As you turn the spring, the jam nut rides along. Adjust in 1/4 inch increments and re-measure sag to see when to stop. When you get to the correct sag, screw the upper nut back down to the lower nut. Jam it by judicious use of the drift. I usually look for about 3 to 5 gaps to pass by.

Align the nut gaps/tabs and mark a tab from each nut with a chisel across two aligned tabs, or put some fingernail polish across two aligned tabs. Do this over by the battery, so you can visually check to see if the nuts get loose easily. Measure sag one last time before putting the mud-guard back on. I ended up with 3 1/8" sag when I finished; the bike rides better now.

A note about front sag. Forks have a sag setting also. However, the only way to adjust fork preload and thus front sag is by changing fork springs and/or spacers. There are some bikes that have preload adjusters built into the fork caps, but the CRF230F does not. Short of changing springs, you're stuck with whatever front sag you've got."

Hope this helps