2003 Suzuki GSXR1000 Suspension Tuning

 

Front Suspension Setup:

Preload

Starting Notes:

Need a socket to fit the top of the forks.

Sag needed, approx 25-30mm (with rider on board) to be equally adjusted on both forks

More preload helps prevent the forks from `bottoming out` under severe braking. You can check this by putting a cable tie around the fork leg, near the seal to see how much suspension travel is used when braking on the limit. Ideally you’ll still want about 10mm left of travel if possible. If you’re bottoming out or almost have no travel left then dial in a bit of preload (about one full turn at a time to start with).

It also pushes more weight on to the rear of the bike, which gives better traction. Overdo it and the bike will not turn as well and as quickly, as there's less weight on the front tyre. Too much preload on the front will also cause a harsh ride and make the tyre work harder as it doing more of the suspensions` work now.

Reducing the preload gives more sag at the front end and puts more weight over the front tyre. You will achieve more feel from the front when turning into corners, especially after braking. Go too far and the forks will travel too much under braking and may bottom out again.

 

Rebound Damping

Starting Notes:

• Need a flat blade screw-driver

• Adjusted at top of forks, equal adjustments to be made on each fork.

Rebound damping controls the speed at which the forks return to their original position after being compressed. If there is not enough rebound damping then the forks will `pogo` and bounce around. Giving you the feeling of little control and no feel. It also unloads the front tyre too quickly which could cause loss of front end traction. It can also cause the bike to run wide in corners and harder to hold a line through bends.

So dial in a half a turn at a time and then perhaps a 1/4 or 1/8 turn either way to fine tune. Try it out, you’ll be amazed at the difference these adjustments can make. These adjustments are much more than recommended, but we suggest these as you`re more likely to notice the difference and you can then fine tune afterwards. Most bikes we've seen have been lacking in rebound damping front and rear.

 

Compression Damping

Starting Notes:

• Need a flat blade screw-driver

• Adjustment on bottom of forks, equal adjustments to be made on each fork.

Compression damping controls the rate at which the forks compress. Again, generally we find road bikes are too soft here as well.

Wind it up a bit and your bike will dive less under braking and work much better on smooth roads and track days with much more feel from the front tyre. Too much compression will firm up ride and turn a bike from a smooth ride into a boneshaker. Over do it completely and the forks wont compress quickly enough causing instability especially over bumpy roads. This also makes the tyre work harder, causing more wear as it`s doing more of the suspensions work than it should be.

Back the compression damping off and the bike will cope with bumps better and use more of its travel to make things smoother. Turn it off too much and the front will dive too quickly under braking and placing too much weight transfer to the front tyre too quickly, potentially overloading to the point of losing traction of the front tyre.

 

Rear Suspension Setup

Preload

Starting Notes:

• C-Spanner from OEM toolkit.

• Adjustment near top of the shock.

Normally adjusted with a C-Spanner. Sag is the amount of suspension travel your bike takes up just supporting its weight or can also be measured with the rider on it. It should be about 20-25mm loaded (with rider & gear) at the rear for the road and less for the track. Increase the preload and the bike will sag less.

More preload will raise the rear ride height which will make your bike steer quicker and change direction faster. But too much will make it unstable.

Sag measurements are a very general guide for most road bikes and are debateable, but if you`re in the range you should not be far off. We prefer to set the sag with the rider on the bike as this will tailor the sag for you individually.

When carrying extra weight ie: a pillion, you`ll also need a bit more rear preload as well as more front preload, so giving you more usable suspension travel again and reducing the chance of `bottoming out` the suspension.

 

Rebound Damping

Starting Notes:

• Need a flat bade screw-driver

• Adjustment found at bottom of rear shock normally

Again an area where we've noticed most road bikes need a bit more. When adjusting, again start with 1/2 turns at a time to get a feel for it and then fine tune again. Standard settings are generally about 1 1/2 to 1 3/4 from the fully screwed in position so yes 1/2 turns at a time is a lot, but it will be easier to see how certain adjustments effect the bikes handling. It really is down to practice and getting a feel for it.

It's probably too soft also, if like the front rebound, it is bouncy and pogos a bit much. ‘wallowing’ is also another indication that the rebound damping may need increasing.

 

Compression Damping

Starting Notes:

• Need a flat blade screw-driver

• Adjustment found towards top of shock.

This controls the rate at which the shock is compressed. Wind it up too much and you'll be bouncing out of the seat over bumps and more likely to get a rear end slide coming out of the corners on the power as the rear is reluctant to grip efficiently as it should be squatting more to get the weight over the rear.

Too much rear compression will put the tyre under too much stress as you put the power down. Get it spot-on and the bike will track straight and hold a tighter line and be able to get the power down more easily as the rear needs to squat a little to get a bit of weight transferred to the back.

Back the rear compression off too much and the rear of the bike will squat down too much, causing understeer (running wide). It will also cause the front tyre to go light. The result is that you will run wide in corners. Wind it off too much and the bike may bottom out over bumpy roads and wallow around under pressure.

Conclusion

When making adjustments to your suspension, always work on one aspect at a time, i.e. the rebound, compression or damping, always make notes of what you do so you have a reference should you want to change things back again in the future, and remember that there's no perfect suspension setup possible, it's always a compromise, depending on where you're riding.

Also, before you make any changes to your suspension, ensure your tyre pressures are set at the correct level for the type of riding you are doing, as the pressure of the tyres is critically important to the handling of your bike. This small fact should not be overlooked. Worn tyres will also adversely affect the handling and this should be addressed before trying to evaluate the suspension settings.

If you make changes to your suspension settings, why not discuss it in the forums to let others know how you get on? Someone might learn from your adjustments and experiences. Please also remember to take it easy when test-riding your bike after making a change, and to work the pace up progressively so you become acustomed to the changes, rather than being surprised mid-corner when it doesn't behave as you expect.

 

Front Forks:

The front wheel ”chatters” entering a corner, the problem goes away, as soon as you let the brakes off, or when you get on the power.

• This is caused by the fact that the fork is working too low in the travel and reaches the progressive, hard part at the end of the travel.

• Put on more pre-load.

• Change to a harder spring.

• If a lot of stroke remains after riding, drop the oil level. See oil level chart.

• Make sure the front forks have no friction.

• Rear ride height is to high, too much rear spring pre-load.

• Lower the rear end by taking off pre-load from rear shock spring.

 

The front wheel is jumping during the last part of braking.

• If a lot of stroke remains, the oil level is too high. Lower the oil level.

• If the fork is bottoming, put in harder springs and keep the oil level.

 

The front end feels unpredictable and unsafe in the middle of the corner (between braking and getting on power). (In my case I was feeling the front very heavy and unsafe)

• Not enough rebound damping. Put on more damping.

• Too much rebound damping. If it at the same time feels harsh, take off some rebound damping.

• Too much compression damping. Also gives a harsh feeling. Take off some compression damping. The front end loses grip coming out of a corner.

• Not enough rebound damping. Put on some more rebound damping.

• Too much pre-load. Take off some pre-load.

• Rear end is too soft. Put on a harder rear spring.

• Front end is too high. Lower the front end by pulling the fork legs

Rear Shock:

If the motorcycle feels unstable, loose and rather bouncy then the rebound damping should be increased.

If the motorcycle is hard and bumpy, especially over a series of bumps, then the rebound damping should be reduced.

If the motorcycle has a low riding position, the low speed compression should be increased.

If it feels unsmooth over small continuous bumps or has bad grip, the low speed compression should be decreased.

If the motorcycle feels unstable in fast corners and has a tendency to bottom easily in depressions and chicanes, the high speed compression should be increased.

If it feels harsh and too rigid or has a tendency to hop during braking, the high speed compression should be decreased.

 

Recommended settings:

front preload                           5 lines showing

front rebound damping           6 clicks out     

front comp. damping             10 clicks out

rear preload                             26mm from top of threads to preload ring

rear rebound damping             12 clicks out

rear comp. damping                6 clicks out

Set fork tube height to 7mm showing from top of triple clamp.