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rear sag setting?


MikeOK

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I read through the service manual and could not find the rear sag setting, I could not even find where it mentioned sag. Where do you guys run yours? Mine seems a little firm at the stock sag setting. TIA

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You probably won't find anything under sag in the manual, try "rear preload". You might even be better off looking in the owners manual, I doubt the service manual covers much on suspension setup.

What is your current sag?

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I can't say exactly right right at the moment, but it barely moves with my weight on it. I have more of an offroad & mx background so I'm really not sure how to set up a sport bike. Plus I'm dealing with 4" of travel instead of 12", so I'm thinking maybe the tuning process is a little different.

I did have another reason for asking as well, I would like to lower it about 1/2" or so and this would be very easy to do by reducing my spring preload, thus increasing sag. But, since I have zero experience tuning suspension on a sportbike I thought I would ask first. I will probably raise the forks in the clamps by the same amount.

Before somone asks why, I have a pair of convertibars on the way and the main reason I want to lower it 1/2" is to compensate somewhat for the higher COG I will have with the altered handlebars.

Also, I have read some comments here about this topic, and I think maybe some are confusing "preload" with "damping". The damping screw should have very little effect on sag, it should only effect the rate of damping (and I assume only compression damping on this shock). Preload normally is related to sag, or, it is the amount of spring tension in the static state (?)

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The rear shock is ajustable only for preload and rebound damping. Damping ajustments will have no affect on sag.

Preload (and sag) is ajusted via the two locknuts on top of the spring, you generally want your sag to be 1/4 to 1/3 of total travel, just like on dirtbikes. You want to ajust ride height, go ahead, but getting out of your optimal sag range to do it is a bad idea.

Not sure if that last bit of your post was a statement or question.......?

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Not sure if that last bit of your post was a statement or question.......?

Actually it was a statement, but I was not absolutely sure I used the right terminology.

1/4 - 1/3 seems to be the universal sag, I didn't know if it applied to sportbikes as well. I'm fairly sure mine is set too stiff, the ride reflects this as well. When I am in the twisties and hit any kind of groove or bump, the bike feels too tight (as in not enough sag to initially "push" the rear wheel into the hole). Anyway, I got off topic on my own post, but this seems to confirm that I can solve two problems with one adjustment. Thanks...

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30-35mm is recommended sag. To do it right takes quite a few hands. With bike unloaded lift the rear and let settle, take measurement (I usually use from swingarm to a piece of tape I put on the tail fairing), then push down on rear and let it slowly come up. Take measurement. You want to find the average between these two as your actual starting point. Then with you in full riding gear, sit on the bike (helps to have someone holding the front upright so you can put your feet on the pegs) and have someone take the measurement again. The difference between your starting point and this measurement should be 30-35 mm. I'm pretty sure 30mm is for racing, where 35 is more for street.

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Your first step describes how to get your "static sag", which is measured against the suspension fully extended, as is "rider sag". If you set 30-35mm between static and rider sag, you'll be running to much sag ("static"+"rider", rather than just "rider"). Both should be measured seperately against the suspension fully extended, wheel off the ground.

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Well, 35 mm would be approximately 1/3 of the travel, which sounds about right, but I'm not sure what my static sag is. In fact I hadn't even considered that, since static sag on a mx bikeisn't so much of a factor. I am at work now, but have 2 days off starting tomorrow and this is on my "tinker list". Thanks for the replies...

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Sorry if I wasn't too clear on the static sag, to get the static sag measurement you have to average the two measurements. First measurement is after you lift the rear and let it down slowly till it stops, second measurement is after you compress the rear (without you on it) and let it come up til it stops. The static sag will be the average of these two measurements. This is done to compensate for "sticktion" of the shock travel in the bushings and seals.

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Your description was great, and is actually the correct way to check rider sag as well.

I was just saying the 30-35mm should be the difference between the suspension fully extended, wheel off the ground, and the suspension with rider aboard, not the difference between static and rider sag.

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You check your static sag after setting your rider sag mainly to see if you're running the right spring rate. Too little or too much static sag will indicate if a spring is too heavy/light for your application once rider sag is set.

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