With every action there is a reaction right? This is no different when it comes to dirt bikes and the mechanics of each change/adjustment. Since suspension is always a hot topic with motocross machines, I thought why not give you guys some insight on what each change point/adjustment available to you on the fork, can do out on the track (good or bad). The action of one change can have reaction on the opposite end of the machine as well, not just the focused area. Here is a “fork” breakdown of action and reaction. Look for the “shock” portion of this article up soon right here on keeferinctesting.com.
Fork:
Air Pressure: Effectively setting the air pressure in an air fork, higher or lower, is the same thing as going up or down on your spring rate.
Action/Stiffer: Stiffening (or raising) the air pressure can allow your fork to ride higher in its stroke, can create more hold up on slap down, de-cel, etc., can make the ride attitude of the bike ride higher in the front, increase firmness in which you hit obstacles with the front end.
Reaction/Stiffer: Going too stiff can cause harshness or a too firm feel when hitting bumps, can cause deflection when fork is light in its stroke (near the top), can cause less front wheel traction (especially on lean angle), pushing sensation through area 2 (middle) of corners, allow the bike’s ride attitude to be too front end high, effectively causing the shock to feel low in the stroke under acceleration, which can make rear end feel too firm or give rider less rear wheel traction.
Action/Softer: Softening (or lowering) the air pressure can increase plushness, allow the fork to move further down in the stroke under load, make the action of the stroke faster, can increase front wheel traction (especially on lean angle), give a more supple feel to the hands through the bars.
Reaction/Softer: Allow the fork too dive on de-cel, create a low front end feel that allows the rear end to kick you on braking bumps (rear shock overpowers the front end), causes too much pitching on/off throttle (teeter totter movement), oversteering through area 2 of corners, harsh feeling (firm) around the track because the fork is riding in the stiffer part of the stroke/damping, fork bottoms out more than 2-3 times per lap, can cause the shock to ride too high in the stroke and give rider harsh feeling off throttle.
Compression: Compression damping/clickers are there for you to allow your fork’s stroke to stiffen or soften up when compressed.
Action/Stiffer: Depending on if you’re a Showa, KYB, or WP rider will depend on how many clicks you can adjust to actually feel a difference. Showa forks are more sensitive to clicks than that of a WP or KYB fork. I would adjust one click per adjustment with a Showa fork and two clicks each adjustment with the other two brands if you want to feel a difference. Going to a stiffer compression setting on your fork can also give the rider a plusher feeling if he/she is too low in the stroke to start with. Stiffer can create better hold up in soft conditions such as deep/tilled loam, sand, mud, etc. Increasing compression can make the ride attitude of the bike ride higher in the front, as well as increase firmness in which you hit obstacles with the front end.
Reaction/Stiffer: Negative affects of going stiffer can range from deflection on/off throttle, rigidity feeling up, increased headshake on throttle, too firm of a feel when hitting bumps, harsh feeling through bars, less front end traction (especially on lean angle), pushing sensation of the front wheel in area 2 of corners, allow the bike’s ride attitude to be too front end high feeling effectively causing the shock to feel low in the stroke under acceleration, which can make rear end feel too firm or give rider less rear wheel traction.
Action/Softer: Softening the compression can increase plushness, allow the fork to move further down in the stroke under load, make the action of the stroke faster, can increase front wheel traction (especially on lean angle/more tire contact patch), give a more supple feel to the hands through the bars.
Reaction/Softer: Allow the fork too dive on de-cel, create a low front end feel that allows the rear end to kick you on braking bumps (rear shock overpowers the front end), causes too much pitching on/off throttle (teeter totter movement), oversteering (knifing) through area 2 of corners, harsh feeling (firm) around the track because the fork is riding in the stiffer part of the stroke/damping (mid-stroke), fork bottoms out more than 2-3 times per lap, causes the shock to ride too high in the stroke and gives rider harsh feeling off throttle, unbalanced feel around track (more comfort in front end with less performance/hold up than shock).
Rebound: The rebound damping allows the fork to move faster or slower when compressed. It can also act as a type of damping force as well.
Action/Faster: More front end traction because the fork is moving faster, which in turn is causing the front tire to get back to the ground quicker over bumps/square edges, can help straight line stability, can increase plushness through the beginning to mid stroke, can help from front end diving when jumping.
Reaction/Faster: Can cause headshake on throttle, could make fork feel too soft on de-cel through braking bumps (diving), can allow front end to come up too high off faces of jumps (boner air), can cause pushing sensation of front tire through area 2 (middle) of corners/front tire climbing out of ruts, busy feeling front end, which can make you hold on too tight and cause arm pump.
Action/Slower: Can allow for more damping feel (firmer), slow the front end down off throttle which can give you increased front end traction in ares 2 (middle) of corners, less movement of the initial stroke/under throttle while hitting acceleration bumps, can brig front end down more off faces of jumps (less boner air).
Reaction/Slower: Can give rider a harsher feeling on/off throttle when hitting bumps, could make fork feel too firm on de-cel through braking bumps (too high/harsh), front end diving too much (endo) off faces of jumps, can cause a ride attitude that is too low off throttle, that low feeling can give the rider less cornering stability through choppy ruts, allows the rear of the bike (shock) feel high in off throttle situations.
Fork Height: The fork height can allow the rider to customize how much cornering ability he/she wants as well as stability by raising/dropping fork legs inside triple clamps.
Fork Height/Action: Raising the fork height can allow for increased lean angle front end traction, can give the rider a sharper cornering motorcycle, easier initial lean/tip in coming into corners, and a lower front end feel. Dropping the fork height can increase stability on throttle as well as cornering stability through area 2-3 of corners, can allow for a taller front end feel.
Fork Height/Reaction: Raising the fork height can give a rider less stability, more oversteer (knifing) through corners, an unbalanced front to rear feel while riding, so sometimes running a lower sag setting (dropping the rear end) will help increase rear wheel traction through area 3 to exit of corners. Dropping the fork height can give a rider a slower cornering machine (side to side), a front end push through area 2 of corners, too high of a front end feel which, may force you to run a higher sag setting (raising the rear end) because the rear of the bike can feel too low under acceleration with the fork dropped in the clamps.