setting sag

[TopTier]

anyone know how to set sag and what to help?

[rybo]

Jonathan,

It's not too hard, but you need a couple of people to help you out. I'm no where near available this week. Are you by any chance coming to R2SL? If so, Dave from www.fixmybike.com (http://www.fixmybike.com) is going to be out there doing suspension set ups for a reasonalble fee....

s

[Knuckle Dragger]

Your bike's sag is broken into two categories: "static sag", the distance your bike compresses its suspension from fully extended when you and gear are aboard and "free sag", the distance your bike settles from full extension under its own weight.
To measure static sag you need two assistants and metric tape measure. Before you mount the bike, you'll want to measure the suspension when it's completely topped out. For the fork, lift on the grips until the front wheel begins to come off the ground. On traditional forks, measure from the stanchion wiper to the bottom of the triple clamp. Measure from the wiper to the top of the axle clamp on inverted forks. Name this number L1 and write down the measurment.
Now get on the bike having one person hold the rear while you get into a riding postion on the bike. The other person will push down on the forks and allow it to rise slowly until it stops. This measurement will be called L2. The front end now will be lifted and allowed to settle slowly until it stops making measurment L3. In the middle of measurment L2 and L3 is the point the fork would want to live in a frictionless system. So the average between the measurements would be (L2+L3)/2
You can determine the static sag by subtracting the average measurment calculated above from L1 or static sag = L1-(L2+L3)/2. For street riding optimum sag is between 30 and 35mm (1.25-1.5 inches); track is 25 to 30mm (1.0-1.2 inches)
Too much sag increase the forks preload; too little og sag back off the preload a bit. Repeat the process with the rear suspension. Key to getting an accurate measurement in the back is to pick a soild point on the frame or bodywork directly above the axle. If you do not measure straight up from the axle you may get inaccurate numbers.
Now static sag is set you can set the free sag. Measure the amount the bike sags under its own weight. Want to be anal use the equation from above or a single quick measurement will put you where you want to be. Free sag should be between 0 and 5mm simply lifting the weight of your bike to see if it moves up slightly before topping out the suspension will give you an idea of how much sag it has. If your suspension has no free sag, your spring rate is too soft. The soft rate forced you to use too much preload to get desired sag. If you have a bunch of free sag, your spring is too stiff and may need to be replaced


Taken from Brasfield's 101 Sportbike Performance Projects

Would like to help but I am in Loveland and might be a ride for you but let me know.

[DevilsTonic]

I had the guys at Faster / TK set the suspension on my bike up for me. It's easier than trying to do it on your own. :up:

[txrc51fatboy]

http://www.gostar-racing.com/club/motorcycle_suspension_set-up.htm