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Setting Sag

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Hi guys,

I have printed off alot of info about setting sag on my new bike but i still don't get it. I do all the measurements and come up with an answer but don't know what i am supposed to do about it. :) Here is the formula that i printed off:

1. Unloaded (without rider): Bike on a stand with rear suspension fully extended

2. Loaded - with rider: Bike on the ground

3. Loaded - without rider: Bike on the ground

To calculate the race sag dimension, subtract the "loaded - with rider" dimension from the "unloaded" dimension.

An example is this:

Unloaded 671 mm (26.4")

Loaded with rider - 568 mm (22.4")

Race Sag = 103 mm (4.0")

But where do i measure the 103mm from? is it the length of the spring or from axle to reference point or where?

Then it gets into the whole free sag thing and i am lost again.

Free sag indicates the distance the rear suspension should sag from the weight of the sprung portion of your bike. To calculate the free sag dimension, subtract the "loaded - without rider" dimension from the "unloaded" dimension. Do this with your bike set at the standard race sag.

Unloaded 671 mm (26.4")

Loaded w/o rider - 651 mm (25.6")

Free Sag = 20 mm (0.8")

Once again i don't know what to do with the number. Both me and my dad have looked at this and cannot understand it. We have never set any bike up before. Probably just stupidity on our part. :)

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Where to do the measurement is relative. You can measure from the rear axle up any fixed spot on the bike. IE. the rear fender. Just use the same spot for all measurements and make sure the point is straight up from the axle.

With the bike on a stand (rear suspension fully extended) you'll get a measurement of IE. 30"

With you sitting on the bike and the suspension compressed, you'll get another number. This is the measure you adjustment to get the right sag. If the first is 30", you want 26" compressed. Meaning the suspension is compression 4" with you on it, vs no load at it (remember, the weight of the bike itself is load)

That's all there is to it. :)

I don't know what the important of free sag is. But since it's dependent on the real sag, you can't adjust it anyways. So don't worry about it. Just get your sag set to 4" and you'll be in the ball park.

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Sag is the difference you want between both the loaded values (with rider and without rider) subtract the difference to get sag. You want 100mm of sag. To get less sag, tighten the preload nut on the top of the spring. For less, loosen the nut. The difference between loaded without a rider and unloaded should be about 20mm.

Measure this point from the axle bolt to a constand point. I use the intersection of the numberplate and the rear fender. Just slip the tape measure behind the numberplate.

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Well, now I'm confused :D I thought it all had to do with #1 and #2. #3 :D what the hell is #3 ;):) What is the difference between #2 and #3 :D How (where :) ) are #2 and #3 measured : :p:o:D:D

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Don't worry buddy you are not alone. I still am confused, i think i will need someone to show me as they are doing it before i figure it out. I keep hearing different ways to do it and then i just get more confused. :):)

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Put the bike on the stand so the rear is fully extended. Measure from the axle bolt to the seat bolt. This is your first measurement it will never change write it down. Now take your bike off the stand sit in the center with both feet on the pegs hands on the handlebars (you will need help balancing here.) Have whoever is helping measure again from the axle to the seat bolt with you sitting balanced on the bike. This is your second measurement. You subtract this second measurement from the first measurement. The number you get is your sag. You want your sag to be 100mm. If it is greater than 100mm tighten the collar down on the shock until you get it correct. If it is less than 100mm loosen the collar until you get 100mm differnce between the two measurements. This will probably take a few adjustments measurements to get right. When you get this done you can come back and ask about the third measurement, static sag :)

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Put the bike on the stand so the rear is fully extended. Measure from the axle bolt to the seat bolt. This is your first measurement it will never change write it down. Now take your bike off the stand sit in the center with both feet on the pegs hands on the handlebars (you will need help balancing here.) Have whoever is helping measure again from the axle to the seat bolt with you sitting balanced on the bike. This is your second measurement. You subtract this second measurement from the first measurement. The number you get is your sag. You want your sag to be 100mm. If it is greater than 100mm tighten the collar down on the shock until you get it correct. If it is less than 100mm loosen the collar until you get 100mm differnce between the two measurements. This will probably take a few adjustments measurements to get right. When you get this done you can come back and ask about the third measurement, static sag :)

Now that is how i need it explained. Dumba$$ terms. :) Thanks heaps. I will have a look at it this afternoon and adjust to suit. Will the static sag affect the race sag when i go to set both?

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Static sag is just a measurement to see if you have the right spring. After you set the race sage to 100mm the static sag(bike off the stand no rider) should be about 25mm if it is much more or less than that you need to respring for your weight.

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Looking over my post I got all mixed up. The other TT'rs are correct. I haven't done mine in so long I got mixed up. Whoops!

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