Dertco Motorcycle Suspension

Setting suspension sag is the very first step in setting up any bike suspension. Do I'll show you how The amount of suspension compresses under the weight of the rider is called rider sag or laden sag. An easy way to think about sag is as a measure of how much suspension travel is available to extend down into dips Setting sag ensures that your rake, trail, ride height and other important factors are wit As a general rule, sag should be about 1-1-1-4 of total suspension travel. That typically works out to about 30-40mm for most sport bikes, snakeids and sport tours. To measure sag, you'll need the bike, the bike's rider and full gear, a notepad and pen, a tape measure, preferably a metric one, and any tools needed to adjust your bike's front and rear preload. If you have a front wheel chalk, that's going to be really helpful. Otherwise, plan on working next to a wall so the rider can reach over and balance I'll be demonstrating the race tech method of checking suspension sag. It's a little more involved, but I feel it's a lot more accurate because it takes into account drag wit Start with the front of the bike. You need to measure the suspension fully extended. If your bike has a center stand, that's pretty easy. If your bike doesn't have a center stand, ask your rider to carefully lean the bike over on the side stand so that the front wheel is off the ground. Then, measure the exposed portion of the lower fork leg. If your bike has a right side up fork, measure from the axle to the lower triple clamp. Write this n So, first we're going to press down on the suspension and then let it rise slowly. T And once again, you're measuring the exposed fork slider. So, we've got 87 millimeters. Writing that down as L2. Next, we're going to lift up on the front of the bike and then let it settle gently. And once again, measure. T 97 millimeters. If there was no drag or friction wit But because of the fork seals and the bus And that's why we've got a difference between those two figures. Now, let's do a little math to find out what the SAG figures actually are. You need to average L2 and L3 and then subtract that figure from L1. So, the total equation is L1 minus L2 plus L3 divided by 2. For that's a little more than we're after. So, we're going to add some preload in order to bring the SAG figures into the appropriate range. Adjusting the preload on t You just have to turn the adjusters on the top of the fork here. Your bike will With the SAG set on the fork, we're now going to check the rear SAG. Roll the bike out of the stand. And just Measure from the axle to an obvious point on the tail. Here we've got a little painted grap T Now to get your L2 and your L3 measurements, you need to put the bike back in the wheel shock and have the rider get back in position. Once again, push down on the bike and allow it to rise slowly and then re-measure. Then, lift up on the bike and allow it to settle and measure again. T And just T If your bike's rear SAG needs to be adjusted, check your owner's manual to see how that's done. And it's always a good idea to write down any changes that you make. If you're unable to nail your SAG figures with the adjustments available on your bike, that's a good indication that your spring rates are off. If you've maxed out preload and you still have too much SAG, that's a sure sign that you need stiffer springs. On the other hand, if you've pulled all of the preload out and you still have too much SAG, your springs are too stiff. The ideal setup will have very little preload to ac And listen, despite what anyone says, adding preload does not stiffen a spring. Rather, it changes the amount of force required to initiate spring movement and the total force required to fully compress or bottom the suspension component. In essence, changing the preload alters the effective range of the spring stroke that is used. Okay, hopefully t If you want to know more, we've got several articles on the topic at MotorCyclistsOnline. com. Now go check your SAG and check back in two weeks for more tips from the MC Garage.