The basic reason as to why you have suspension on your motorcycle is to maximize traction, have control while you ride whilst adding the highest level of comfort while achieving all those tasks.
The ideal setup will be a setup tailored to your motorcycle combined weight with the rider, type of terrain it will be used, and other variable factors such as level of riding, luggage , passenger, tire choices and the list can go on. For this reason, there are specialists, like us, that have worked many years to provide you with guidance and the expertise through the service we provide to attain your goals: make your motorcycle handle the way you need it and the way you want it.
There are 2 basic systems on any suspension systems: springs and damping.
Springs provide you with the support to hold the weight of the bike and its load at a certain height while absorbing bumps and depression on the road and “spring” back to its original position.
Damping controls this up and down movements so they are not too fast nor too slow to maintain contact with the ground at all time while the bike travels through the terrain and at any lean angles, and provide you with a level of comfort.
What is sag and how do I measure?
Sag is the amount the springs compress between the suspension fully extended and fully loaded with the rider on board in riding position. To get consistent measurements and the correct calculation of your sag numbers it is important to follow the right steps and be consistent with the procedure every time.
Step 1: Lift the bike in a way that you can extend the suspension completely by getting the wheel off the ground. Measure the distance from the axle perfectly vertical to some point on the chassis. If there is no point on the chassis or body work that you can consistently and precisely measure repeteadly you can use blue painters tape and draw a mark to achieve this. This measurement is L1. If the measurement is not exactly vertical the sag numbers will not be correct.
Step 2: Lower rear wheel back to the ground and straighten bike to allow the weight of the bike (without rider) to compress the suspension. Take a measurement from the same point on the rear axle to the same point on the chassis. This measurement is L2.
Step 3: Put the rider on board in riding position. Have a third person hold and balance the bike from the front. Now you will measure the distance between the axle and the mark on chassis again. This measurement it L3.
Step 4: Now you can calculate sag L1-L2= free sag and L1-L3= Total sag ( aka rider sag or static sag)
This are some general guidelines of sag numbers ranges.
Street bike Front sag 35-45 mm Rear free sag 5-10 mm Rear Total sag 30-40 mm
Road race Front sag 30-40 mm Rear free sag 2-10 mm Rear Total sag 25-35 mm
Dirt bikes Front sag 65-75 mm Rear free sag 25-50 mm Rear Total sag 95-110 mm
Step 1: Extend the fork completely until wheel is off the ground. Measure from the wiper or dust seal to the bottom of the triple clamp if it is a conventional fork or lower fork axle bracketupper edge on inverted forks.This measurement is L1.
Step 2: Lower bike back to the ground and allow the weight of the bike to compress the suspension on its own without the rider. Measure again from the same point if the seal wiper to second measure point as before. This measurement is L2.
Step 3: Mount the rider back on the bike in riding position. It is common to encounter fork stiction and this could be cause by several things so to find out if you do have stiction on you fork and also to continue with your front sag measurement follow this extra step. With a third person holding the bike straight and balanced push front end down and let it extend slowly, take measurement and this is L3. Then pull front end up and let it compress down slowly, then take measurement and this is L4.
Step 4: Now you can calculate sag as follows:
L4-L3 = amount of stiction on your forks.
calculate L3+L4= X then divide X/2 = L5
Step 5: Calculate sag
L1-L5 = Total sag (aka rider sag, static sag)
Why do I need to change springs for my weight and riding style?
Once you measure sag you may find out that your sag numbers do not fall into the appropriate range for the type of bike, riding style and rider’s weight. If you have adjustments on your suspension you may try to adjust the spring preload to achieve this sag numbers but if even after adjustments you can’t then that is a sign of a wrong spring. Spring rate and sag are very important to maintain the geometry of your bike as intended for the type of riding the motorcycle was design for and also to ensure your suspension is working n the right portion of its travel to give you the best comfort and performance that you need.
How often do I need to service my forks and shock?
Forks and shock have oil inside that provide you with controlled damping that allows the bike to perform with control over the terrain is ridden on. This oils as with your engine or any other component that functions with it, provides lubrication but in suspension based on its degradation it also is directly link to the performance of the damping that provides. This together with contamination from various internal components that wear, need to be serviced and changed often so there is not permanent damage that will cause your suspension to need replacement or very expensive repairs.
Service intervals vary based on used but general guidelines are as follow:
Street bikes forks 10000 miles shock 14000 miles
Road racing bike ( based in use) forks and shocks every 6 months minimum.
Offroad bikes every 10000 miles or more often depending on dust conditions and hard use.
How do I know if my suspension components need service?
The first thing to check for is any leakage through the fork or shock seals. This is particularly important in the front forks since the oil will find its way to your brakes disks and pads which will compromise the bikes ability to stop.
The next will be to check service intervals and see if you are due based on mileage or usage.
Another will be a decrease or lack of performance of your suspension, feeling unusually bouncy, or it moves too slow up and/or down, or if in general you are not satisfied with the suspension or chassis performance of your motorcycle, which may indicate that it may need to be upgraded as well as serviced.
What is a cartridge upgrade?
Some motorcycle forks have cartridge systems already from the factory but many still use basic damping rod components to create damping in your fork. Damping rod system have a very limited range of damping and some cartridge systems suffer from the same lack of performance as well as not being externally adjustable in many cases. Even those that are adjustable and engineer with performance in mind are not suited in many cases to the rider’s weight, riding style and all other variables. Aftermarket cartridge upgrades provide you with higher quality , more adjustability, tailored fitment and tuned for your needs and application; which that will offer you with better performance, comfort and serviceable life of your suspension and thus you can enjoy your motorcycle more and for a longer period of time.
What is a 20 mm piston kit?
Most Motorcycle OEM manufacturers forks that have a cartridge system have a 20 mm piston kit in them but in many applications their performance has a lot left to be desired.
These kits are replacement pistons and shims that improve the dynamic function of your fork and are custom tuned for each bike and rider.
Your bike will have over-all better feeling from the front tire, this will let you be able to gain more confidence and enable you to brake deeper and harder into the corner.
These kits are the best "cost effective" way to improve the function from your front fork.
The fork will have a full service done to them when the 20mm kits are installed.
How do I pack my forks and/or shock for shipment?
Depends on the size of your fork and/or shock you are about to ship we recommend you pack it in a suitable box; wrap the items in bubble wrap, then add some packing material on all sides of the box as you are packing the item in where the items will not damage each other nor they have room to move while shipping which can cause the item to puncture the box and get exposed to damage.
What is the best way to ship these items?
Please use UPS or FedEx and do not forget to add the appropriate amount of insurance to replace your items if they get lost or damaged beyond repair during shipping.
In many cases you want to ship the forks in a separate box than the shock to avoid any damages.
What do I include in the package with my forks and shock?
Include your items to be serviced/repaired as well as a service form.
You need to print a service form, which you will find on our website, then fill that completely with all information required and if you have any special requests or information such as any important history of the item that will aid us to understand a problem, please include that on the form as well.