Author Topic: Suspension Setup ( ST1300 ) *  (Read 10164 times)

Offline KoTAOW

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Suspension Setup ( ST1300 ) *
« on: April 10, 2012, 06:22:39 AM »
Submitted by John Herring, aka JohnnyRide
Original article can be found here: Suspension Setup

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Suspension Setup ( ST1300 )


A more exacting method:

For a base-line set-up you can do the following and then fine-tune from there. (You'll need some friends to help you measure since you'll be on the bike.)

- Put the bike on the center stand to get the rear wheel off the ground and extend the suspension.

- Use a measuring tape to measure from the center axle up vertically to a point on the chassis. Measure in millimeters to make doing the math easier. Record this measurement and label it M1.

- Take the bike off the stand and have a couple of folks help hold the bike up while you get on it in riding position. Have a third friend push the rear down about an inch and let the rear come back up slowly (don't bounce it). When the suspension stops, measure from the center axle to the chasis point you measured to before. Record this measurement and label it M2.

- With you still in the riding position get your third friend to lift up on the rear of the bike about an inch and let it settle slowly (still no bouncing). The measure again from the center axle to the chassis point. Record this measurement and label it M3.

Do the following math:
M1 - [(M2+M3)/2]

This gives you your static spring sag. Ideally your sag should be set somewhere around 28-33% of total travel for street riding (front and rear) which translates to somewhere between 30-35 millimeters. Too much sag means you need more preload while too little sag means you need less preload. If you run out all your adjustment and still have too much sag you'll need stiffer springs. If you run out all your adjustment and have too little sag you'll need shorter or lighter springs.

You do the same thing to measure your front sag and you'll want 30-35 millimeters of sag there as well. Since the ST doesn't have front suspension adjustments you may find you need to adjust the thickness of the oil, add spacers, cut the springs (not likely), or get different springs in order to get a good sag set-up.

Doing the above will give you a base-line suspension set-up for front and rear. You can then adjust that further based on your riding style and preferences. If you're planning a track day, you might want to stiffen things up and run it in the 23-27% range (25-30mm) because you're not worried about road bumps or uneven pavement. For daily riding you might decide you want things to run a bit softer and run your sag closer to 33% (35mm). Then for twisties you might decide to run in the 27-28% range.

Prior to doing these measurements, I set up my suspension based on what others on this board had suggested with my preload and damping set extremely stiff. I did these measurements and found my preload about right (2 1/2 lines visible) but my rebound damping was way too stiff. I had the rebound a half turn out from full and needed to bring it to about four half turns out from full (with riding, I've since adjusted it to three half turns from full). I was reluctant to do it because of all the high-speed wobble threads etc. but was amazed at how much more sure-footed the ST felt with the sag properly set.
 

Down and dirty version:

So to set your damping, set it to full hard and bounce it. It will look like the suspension is sticking. Now set it to full soft and bounce it. It will pogo so fast that it actually pulls the wheel off the ground and oscillate. Now, turn it back to full hard and dial it out 2 full turns. Bounce it and it will come up and settle without oscillating. If it oscillates, turn it a 1/4 turn towards hard and bounce it again. This will be darn close to "just right." Play around in 1/4 turns to get it dialed in perfectly - it should come up and settle without looking like it's sticking.

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Thank You again for your contribution John Herring, aka JohnnyRide
« Last Edit: March 24, 2013, 03:59:19 PM by Tom Melnik »