Fitting '06 ZX10r rear shock to Z1000

[Deleted]

Cheers for all the info, I will come back and let you know how I've got on in the New Year. Thanks again

[Deleted]

Can anyone shed some light on the easiest way to understand and set the sag/ As i find it abit of a nightmare to get to grips with.

Phipsy

[Deleted]

stolen from another site, hope they dont mind, hope its what your after
Article on Setting Suspension Sag...
From Race Tech's Paul Thede....now you guys don't have to refer to things like the no. of lines showing on the fork....enjoy! -PC (PumaCat)
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Suspension and Springs
What's all this ruckus about suspension these days? It seems everyone is clued in that suspension setup can be a key to riding fast and safely, but how do you do it? No matter what shock or fork you have, they all require proper adjustment to work to their maximum potential. Suspension tuning isn't rocket science, and if you follow step-by-step procedures you can make remarkable improvements in your bike's handling characteristics.

The first step to setting up any bike is to set the spring sag and determine if you have the correct-rate springs. Spring sag is the amount the springs compress between fully topped out and fully loaded with the rider on board in riding position. It is also referred to as static ride height or static sag. My company, Race Tech, (909/594-7755) has an advanced method of checking spring sag that I'll describe.

If you've ever measured sag before, you may have noticed that if you check it three or four times, you can get three or four times, you can get three or four different numbers without changed anything. We'll tell you why this occurs and how to handle it.

REAR END
Step 1: Extend the suspension completely by getting the wheel off the ground. It helps to have a few friends around. On bikes with sidestands the bike can usually be carefully rocked up on the stand to unload the suspension. Most race stands will not work because the suspension will still be loaded by resting on the swingarm rather than the wheel. Measure the distance from the axle vertically to some point on the chassis (metric figures are easiest and more precise; Figure 1). Mark this reference point because you'll need to refer to it again. This measurement is L1. If the measurement is not exactly vertical the sag numbers will be inaccurate (too low).

Step 2: Take the bike off the stand and put the rider on board in riding position. Have a third person balance the bike from the front. If accuracy is important to you, you must take friction of the linkage into account. This is where our procedure is different: We take two additional measurements. First, push down on the rear end about 25mm (1") and let it extend very slowly.

Where it stops, measure the distance between the axle and the mark on chassis again. If there were no drag in the linkage the bike would come up a little further. It's important that you do not bounce! This measurement is L2.

Step 3: Have your assistant lift up on the rear of the bike about 25mm and let it down very slowly. Where it stops, measure it. If there were no drag it would drop a little further. Remember, don't bounce! This measurement it L3.

Step 4: The spring sag is in the middle of these two measurements. In fact, if there were no drag in the linkage, L2 and L3 would be the same. To get the actual sag figure you find the midpoint by averaging the two numbers and subtracting them from the fully extended measurement L1: static spring sag = L1 -[(L2 + L3) / 2].

Step 5: Adjust the preload with whatever method applies to your bike. Spring collars are common, and some benefit from the use of special tools. In a pinch you can use a blunt chisel to unlock the collars and turn the main adjusting collar. If you have too much sag you need more preload; if you have too little sag you need less preload. For road race bikes, rear sag is typically 25 to 30mm. Street riders usually use 30 to 35mm. Bikes set up for the track are compromise when ridden on the street. The firmer settings commonly used on the tract are generally not recommended (or desirable) for road work.

You might notice the Sag Master measuring tool (available from Race Tech) in the pictures. It's a special tool made to assist you in measuring sag by allowing you to read sag directly without subtracting. It can also be used as a standard tape measure.

Measuring front-end sag is very similar to the rear. However, it' much more critical to take seal drag into account on the front end because it is more pronounced.

FRONT END
Step 1: Extend the fork completely and measure from the wiper (the dust seal atop the slider) to the bottom of the triple clamp (or lower fork casting on inverted forks; Figure 2). This measurement is L1.

Step 2: Take the bike off the sidestand, and put the rider on board in riding position. Get and assistant to balance the bike from the rear, then push down on the front end and let it extend very slowly.



Where it stops, measure the distance between the wiper and the bottom of the triple clamp again. Do not bounce. This measurement is L2.

Step 3: Lift up on the front end and let it drop very slowly. Where it stops, measure again. Don't bounce. This measurement is L3. Once again, L2 and L3 are different due to stiction or drag in the seals and bushings, which is particularly high for telescopic front ends.

Step 4: Just as with the front, halfway between L2 and L3 is where the sag would be with no drag or stiction. Therefore L2 and L3 must be averaged and subtracted from L1 to calculate true spring sag: static spring sag = L1 - [l2 + l3) / 2].

Step 5: To adjust sag use the preload adjusters, if available, or vary the length of the preload spaces inside the fork.

Street bikes run between 25 and 33 percent of their total travel, which equates to 30 to 35mm. Roadrace bikes usually run between 25 and 30mm.

This method of checking sag and taking stiction into account also allows you to check the drag of the linkage and seals. It follows that the greater the difference between the measurements (pushing down and pulling up), the worse the stiction. A good linkage (rear sag) has less than 3mm (0.12") difference, and a bad one has more than 10mm (0.39"). Good forks have less than 15mm difference, and we've seen forks with more than 50mm. (Gee, I wonder why they're harsh?)

It's important to stress that there is no magic number. If you like the feel of the bike with less or more sag than these guidelines, great. Your personal sag and front-to-rear sag bias will depend on chassis geometry, track or road conditions, tire selection and rider weight and riding preference.

Using different sag front and rear will have huge effect on steering characteristics. More sag on the front or less sag on the rear will make the bike turn more slowly. Increasing sag will also decrease bottoming resistance, though spring rate has a bigger effect than sag. Racers often use less sag to keep the bike clearance, and since roadraces work greater than we see on the street, they require a stiffer setup. Of course, setting spring sag is only first step of dialing in your suspension, so stay tuned for future articles on spring rates and damping.

[glow=red:506f1fe457]And theres more[/glow:506f1fe457]

Street Bike or Road Racing Applications

With incorrect suspension setup, tire wear is increased and handling suffers, resulting in rider fatigue. Lap times can be dramatically slower and overall safety for both street and race enthusiasts is another issue. Add the frustration factor and it just makes sense to properly setup your suspension. The following guide will help you dial in your suspension for faster and safer riding both on and off the track.

Basic Setup: Check the following
1. Forks sag 25-40 mm
2. Shock sag 25-35 mm
3. Check chain alignment. If not correct, bike will crab walk and sprocket wear will be increased.
4. Proper tire balance and pressure. If out of balance, there will be vibration and headshake.
5. Steering head bearings and torque specifications, if too loose, there will be head shake at high speeds.
6. Front-end alignment. Check wheel alignment with triple clamps. If out of alignment, fork geometry will be incorrect and steering will suffer.
7. Crash damage, check for proper frame geometry.
8. Adjustment Locations on Forks

Rebound adjustment (if applicable) is located near the top of the fork. Compression adjustment (if applicable) is located near the bottom of the fork. Spring preload adjustment (if applicable) is generally hex style and located at the top of the fork.

Forks: Lack of Rebound
Symptoms:
1. Forks are plush, but increasing speed causes loss of control and traction.
2. The motorcycle wallows and tends to run wide exiting the turn causing fading traction and loss of control.
3. When taking a corner a speed, you experience front-end chatter, loss of traction and control.


4. Aggressive input at speed lessons control and chassis attitude suffers.
5. Front end fails to recover after aggressive input over bumpy surfaces.
Solution:
Insufficient rebound. Increase rebound "gradually" until control and traction are optimized and chatter is gone.

Forks: Too Much Rebound
Symptoms:
1. Front end feels locked up resulting in harsh ride.
2. Suspension packs in and fails to return, giving a harsh ride. Typically after the first bump, the bike will skip over subsequent bumps and want to tuck the front.
3. With acceleration, the front end will tank slap or shake violently due to lack of front wheel tire contact.
Solution:
Too much rebound. Decrease rebound "gradually" until control and traction are optimized.

Forks: Lack of Compression
Symptoms:
1. Front-end dives severely, sometimes bottoming out over heavy bumps or during aggressive breaking.
2. Front feels soft or vague similar to lack of rebound.
3. When bottoming, a clunk is heard. This is due to reaching the bottom of fork travel.
Solution:
Insufficient compression. Increase "gradually" until control and traction are optimized.
Forks: Too Much Compression

Symptom:
1. Front end rides high through the corners, causing the bike to steer wide. It should maintain the pre-determined sag, which will allow the steering geometry to remain constant.
Solution:
Decrease compression "gradually" until bike neither bottoms or rides high.

Symptom:

Front end chatters or shakes entering turns. This is due to incorrect oil height and/or too much low speed compression damping.
Solution:
First, verify that oil height is correct. If correct, then decrease compression "gradually" until chattering and shaking ceases.

Symptom:
Bumps and ripples are felt directly in the triple clamps and through the chassis. This causes the front wheel to bounce over bumps.
Solution:
Decrease compression "gradually" until control is regained.

Symptom:
Ride is generally hard, and gets even harder when braking or entering turns.
Solution:
Decrease compression "gradually" until control is regained.
Adjustment Locations on Shocks
Rebound adjustment (if applicable) is located at the bottom of the shock. Compression adjustment (if applicable) is located on the reservoir. Spring prelude is located at the top of the shock.

Shock: Lack of Rebound
Symptoms:
The ride will feel soft or vague and as speed increases, the rear end will want to wallow and/or weave over bumpy surfaces and traction suffers.
Loss of traction will cause rear end to pogo or chatter due to shock returning too fast on exiting a corner.
Solution:
Insufficient rebound: Increase rebound until wallowing and weaving disappears and control and traction are optimized.
Shock: Too Much Rebound
Symptoms:
Ride is harsh, suspension control is limited and traction is lost.
Rear end will pack in, forcing the bike wide in corners, due to rear squat. It will slow steering because front end is riding high.

When rear end packs in, tires generally will overheat and will skip over bumps.
When chopping throttle, rear end will tend to skip or hop on entries.
Solution:
Too much rebound. Decrease rebound "gradually" until harsh ride is gone and traction is regained. Decrease rebound to keep rear end from packing.

Shock: Lack of Compression
Symptoms:
The bike will not turn in entering a turn.
With bottoming, control and traction are lost.
With excessive rear end squat, when accelerating out of corners, the bike will tend to steer wide.
Solution:
Insufficient compression. Increase compression "gradually until traction and control is optimized and/or excessive rear end squat is gone.

Shock: Too Much Compression

Symptoms:
Ride is harsh, but not as bad as too much rebound. As speed increases, so does harshness.
There is very little rear end squat. This will cause loss of traction/sliding. Tire will overheat.
Rear end will want to kick when going over medium to large bumps.

Solution:
Decrease compression until harshness is gone. Decrease compression until sliding stops and traction is regained.

Stock Tuning Limitations

The factories plan on designing a bike that works moderately well for a large section of riders and usages. To accomplish this as economically as possible, manufacturers install valving with very small venturis. These are then matched to a very basic shim stack which creates a damping curve for the given suspension component. At slower speeds this design can work moderately well, but at higher speeds, when the suspension must react more quickly, the suspension will not flow enough oil, and will experience hydraulic lock. With hydraulic lock, the fork and/or shock cannot dampen correctly and handling suffers. The solution is to re-valve the active components to gain a proper damping curve. It does not matter what components you have, (Ohlins, Fox, KYB, Showa), matching them to your intended use and weight will vastly improve their action. Furthermore, if you can achieve the damping curve that is needed, it does not matter what brand name is on the component. Often with stock components, when you turn the adjusters full in or out, you do not notice a difference. In part, this is due to the fact that the manufacturer has put the damping curve in an area outside of your ideal range. Also, because the valves have such small venturis, the adjuster change makes very little difference. After re-valving, the adjusters will be brought into play, and when you make an adjustment, you will be able to notice that it affects the way the way the fork or shock performs.

Another problem with stock suspension is the springs that are used. Often they are progressive, increasing the spring rate with increased compression distance. This means that the valving is correct foronly one part of the spring's travel, all other is compromise. If the factory does install a straight-rate spring, it is rarely the correct rate for the weight of the rider with gear. The solution is to install a straight-rate spring that matches the valving for the combined weight of the bike, rider and gear to the type of riding intended.

Remember

Always make small adjustments, more is not always better.
Always keep notes.
Suspension tuning is an art, be patient.

[Deleted]

noddy,
Many thanks for looking up all the info about setting the sag
Top Bloke

Phipsy

[Deleted]

Ah yes. Very useful and just in the nick of time.

[Deleted]

Gee I'm a lazy sod, bought a full zx10 2006 shock and linkages off ebay in November last year, and only just fitted it today, and thats only because I had the rear wheel off to fit a new tyre. What a difference its made. The thing about the ride height being lower has also played into my hands because I'd already had longer tie bars fitted to the rear to lower my bike (me a midget) and also lowered the front 10mm. so when I fitted the zx10 shock and linkages with its own standard tiebars every thing seem to be leveled out correctly and, this is a big and, I can still just about get a toe on the floor. I haven't played with any settings yet but just done a quick 40 miles and the difference is huge. thanks everyone for guidance.