Tuning F.A.Q.'s

General Info

This guide serves to provide some generic information about how to set up your street motorcycle correctly given the OEM suspension you have. Not all motorcycles come with fully adjustable suspension, so you may not have some of the components that we talk about on this page. If you are lacking those components, in some cases they can be added to the bike with the acquisition of components/products and the use of a CNC machine to make the third party parts fit and work. If you have any questions in regard to this, please email us with them!

STEERING HEAD BEARINGS

Each motorcycle has a manufacturers torque setting for the head bearings. Do not exceed this or you will increase the wear on the bearings. Prior to every track day and every race event, these bearings must be checked. Loose head bearings will cause suspension issues, and may result in a lot of time going in the wrong direction. If you are street riding – check them once a month (or more frequently depending on what kind of street riding you do). It is also advisable to check that the top and bottom head bearings are packed with the correct type of grease!

FRONT WHEEL ALIGNMENT

This will create a lot of questions. The only time this becomes applicable is when you remove the forks to have them worked on, or you change the height of forks in the triple clamp to increase/decrease the speed at which the bike steers. Any time this is done, you must check that both forks are exactly the same distance above the upper triple clamp. Using a precision instrument will help with this but a metric ruler will work. Eye balling the height will not work and will inevitably leave the front wheel out of alignment.

CHAIN ALIGNMENT/ADJUSTMENT

Prior to starting any suspension adjustment you must check that the chain alignment and adjustment are correct, because not all stampings on the swing arm will align the rear wheel correctly. You will need a string line that is about 12 feet long.

Find the center of the string line and wrap that section around the rear wheel twice (then tape it in place) and run the left and right ends of the lines forward to two steady objects that must be beyond the front wheel (jack stands work well). Tie the string ends off on the jack stands and ensure that the line is just touching each edge of the side wall of the rear tire. You then measure from the same point on either side of the front wheel to the string line on both sides and compare measurements. Adjust the rear wheel until such time as the distances from both sides of the front wheel to the string line are the same. You need to reposition the line after each adjustment prior to taking another measurement!

Chain adjustment is also critical. If the chain is too tight the shock will not be able to function correctly as the chain will limit the movement of the swing arm. To ensure that the chain is correctly adjusted, sit on the bike and check there is an inch of play (half inch on top and half inch below the normal position of the chain at rest). When retightening the axle nut, use a rag or wrench and roll it physically between the rear sprocket and the chain prior to actually tightening the axle nut. Once set to the right torque, roll the wheel forward and remove the rag/wrench.

NOTE: Both these tasks should be done simultaneously and once the rear wheel is aligned, precise movement of both adjustments will ensure that the rear wheel always stays in precise alignment.

TIRES (track days & racing)

It is critical that the wheels are balanced correctly when tires are installed. There is no substitute for time in getting this done right. It is also important to ensure that the weights used stay on the wheel. We recommend that you use duct tape to cover the weights, which should ensure that they stay in place!

A lot of tire wear is blamed on suspension but in a significant number of cases, it is due to the incorrect pressure in the tire. There are easy ways to check that the tire pressure is correct, so that if there is a suspension issue, it can be accurately identified. This really only applies to track days/racing where speeds are consistently very high both in corners and straight lines. When taking tire pressures, you need to use a quality gauge and have that gauge calibrated so you know how to read the gauge accurately (some will be + or – 1psi).

All manufacturers have recommended tire pressures that put you in the ballpark for the day. However, these pressures do not reflect track or ambient temperatures that change throughout the day. At the start of the day when the tires are truly cold, set the tire pressure to the recommended amount. When you go return from the ride (track or street), immediately take the tire pressure. You should have a gain of 6-7psi. If you do not have that, then the tire pressure must be adjusted again, but you have to wait until the tire is cold again to do this right.

You may get the symptoms of the tire sliding as it is overheating and therefore losing traction, and you may also see the tire “hot tearing” as the rubber shreds in a band around the tire.

You may get the symptoms of the tire sliding as it is not reaching the correct operating temperature and therefore losing traction, and you may also see the tire “cold tearing” as the rubber shreds in a band around the tire.

If you have a gain of more than 7psi, then you have too little air in the tire. You will need to increase tire pressure by half to one pound, and then go ride the bike again. Once you come back in, immediately take the tire pressure again. Adjust as necessary until you reach the correct gain.

If you have a gain of less than 6psi, you have too much air in the tire. Conversely you will need to decrease tire pressure by a half to one pound and then go ride the bike again. Once you come back in, immediately take the tire pressure again. Adjust as necessary until you reach the correct gain.

Throughout the day whether at a track day or a race event the track temperature and the ambient temperature will change, so at regular intervals throughout the day, you will need to check both cold and hot tire pressures and adjust accordingly.

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