Suspension Settings - another one to try?

[Jza]

Just read their review of 2012 Busa vs ZX-14... they posted suggested suspensions settings:

2012 Kawasaki ZX-14R vs Suzuki Hayabusa - Sport Rider Magazine

Suggested Suspension Settings

Front: Spring preload — 6 turns out from full stiff; rebound damping — 6 clicks out from full stiff; compression damping — 7 clicks out from full stiff

Rear: Spring preload — 10mm thread showing; rebound damping — 7 clicks out from full stiff; compression damping — 7 clicks out from full stiff

Thats not what they said back in 2009 LOL... but its the same bike... surely new colours cant make that much of a difference LOL

Anyone tried it out ?

Jza

PS i've read jinxster etc thx

 

[Tufbusa]

There is no magical "One size fits all" suspension setting. Suspension and skill are closely intertwined. Preload for instance depends on how much weight is combined with rider and passenger/luggage as well as how aggressively the rider rides not to leave out rider preference. Jinxters setup is not a bad place to start but its very basic and only gives you a place to start.

As I heard a suspension guy say once "Most home suspension tuners twist knobs until the suspension is noticeably worse and then they stop".

First step is to set your sag "Properly". Only then begin to twist knobs. The most important thing to remember is keep both ends working evenly and in unison.

Preload does not make your suspension stiffer! The trick to setting sag is to put the working portion of the suspension travel in the middle one third of the stroke. Any place between 35-40mm seems to be fine and dandy for street use.

 

[Jza]

As i tried to say.. not after a lesson on how to set up suspension thanks.. just want to know if anyones tried it. The rear settings given on the sportsrider website were 8 and 10 and in this review are 7 and 7.. so its firmer in the rear. Intersted in feedback. Im finding the rebound is a bit too soft at 10 and am getting thumped in the arse over big bumps.. sounds like this might help

Jza

 

[kromdom]

I paid a local shop $30 to get my bike's suspension set for my weight/riding preferences. Get on bike, measure, jump up-and-down on bike, adjust, measure, etc.

 

[isiahstites]

As i tried to say.. not after a lesson on how to set up suspension thanks.. just want to know if anyones tried it.

Well I felt Tuf gave an appropriate anwser and mine would not of been as detailed, but similar. Proper suspension set-up is different for each and every bike and rider. The weight of the bike and rider changes everything.......as stated there is not a "one size fits all".

If you are not sure take it to a shop and have them set it up for you with your normal riding gear on, you will be glad you did.

Good luck,
Scott

 

[Jza]

LOL...

Just to say thanks for posting and suggesting the shop route...

If you have tried the settings, or are going to give them a go and want to post feedback... please post, otherwise, please dont worry - its ok - im fine thank you very much

Have just made the changes and had a quick ride over a bumpy backroad i know. Seems much less harsh at the rear on the bumps at 7 - 7 than it was at 8 - 10. So the increase in rebound 3 clicks was good as it's controlling the bike better on the expansion of the shock after it hits the bumps. Before it was proper kicking me in the arse... now it seems better controlled. Not sure if the front changes are as good... but will have a play.

Jza

 

[Tufbusa]

As with most home tuners you are going to twist knobs until the suspension is noticeably worse then you'll quit.

Your rebound is not what makes the bumps bang you in the arse, its compression. The rebound is what controls the how the spring releases stored energy. Just so you know!

You may not want suspension advise but you desperately need it.

Sportbike Suspension Tuning by Andrew Trevitt - Buy it, you'll be glad you did.

 

[kromdom]

Tuf,
Was watching an Isle of Man video and noticed the front end of bikes did a "headshake or wiggle" as it went airborne on certain areas of the road. Have a serious question and hoping you can assist....cause/explanation for the shake? I am guessing the front suspension losing contact with the ground is the cause...is it the forks "rebounding" as it loses contact with the ground??
Example in :10 of this video (and many more later):

 

[drbig]

Your rebound is not what makes the bumps bang you in the arse, its compression. The rebound is what controls the how the spring releases stored energy. Just so you know!

Well, its both since bumps are usually repeated and stiff rebound will store more energy to the spring.

 

[drbig]

Tuf,
Was watching an Isle of Man video and noticed the front end of bikes did a "headshake or wiggle" as it went airborne on certain areas of the road. Have a serious question and hoping you can assist....cause/explanation for the shake?
Example in :10 of this video (and many more later):

As the front wheel lands, its never straight. Due to the self stabilising effect of trail, the rearward force of the landing on the front wheel, forces it to steer to the opposite direction. This happens fast, so that a gyroscopic effect is induced, which in turn due to the principle of conservation of angular momentum, induces an oscillation at the steering stem.

 

[Tufbusa]

Well, its both since bumps are usually repeated and stiff rebound will store more energy to the spring.

If you want to get technical about bumps that drive your arse up between your shoulder blades the compression adjustment has no effect whatsoever. Its the internal shim stack that dictates how much oil flow passes the orifice at high speed.

You will have to explain to me how rebound decides how hard the seat drives your arse upwards, please?

 

[Tufbusa]

As the front wheel lands, its never straight. Due to the self stabilising effect of trail, the rearward force of the landing on the front wheel, forces it to steer to the opposite direction. This happens fast, so that a gyroscopic effect is induced, which in turn due to the principle of conservation of angular momentum, induces an oscillation at the steering stem.

I agree!

However, the bike gets a case of the shivers when the rear tire gets airborne and touches down before the front. What causes that?

 

[kromdom]

As the front wheel lands, its never straight. Due to the self stabilising effect of trail, the rearward force of the landing on the front wheel, forces it to steer to the opposite direction. This happens fast, so that a gyroscopic effect is induced, which in turn due to the principle of conservation of angular momentum, induces an oscillation at the steering stem.

my head hurts...but i think i understand. Thanks.

 

[drbig]

You will have to explain to me how rebound decides how hard the seat drives your arse upwards, please?

With pleasure...in exactly the same way as compression does.
In the case of high compression the shock is reluctant to compress due to added hydraulic compression force. In the case of stiff rebound the shock is reluctant to compress due to the added spring force, since within a series of bumps the spring will move around a more compressed mean state.

 

[Tufbusa]

What he is saying is the trail (A distance between the center of the contact patch & the imaginary line through the steering stem to the point it touches the deck called RAKE. Trail is the distance from the rake on flat plane to the center of the contact patch) built into the steering. The distance between RAKE & Contact patch is called TRAIL or trailing arm. A harley chopper has a very long trailing arm while a sport bike has a very short trailing arm making the harley steering very heavy to steer but very stable (Never see a steering damper on a harley) due to the leverage of the long arm and the sport bike has a short trailing arm which makes it steer much easier (Quicker) but can be twitchy and sometimes unstable at high speeds thus steering dampers are OEM on most high performance sport bikes.

When the tire gets light or airborne it looses it's alignment due to loss of traction. When traction is re-established the trailing arm by design tries to realign the tire. The tire is over corrected by the trailing arm (Oscillation) and head shake occurs. It's the trailing arm that aligns the tire while the steering damper simply dampens the process.

Sounds a bit complicated but it's really not. If you are interested in Suspension Andrew's Trevitt explains all that stuff in detail with photos. Best suspension book I've read. Andrew really simplifies things very well.

 

[Tufbusa]

With pleasure...in exactly the same way as compression does.
In the case of high compression the shock is reluctant to compress due to added hydraulic compression force. In the case of stiff rebound the shock is reluctant to compress due to the added spring force, since within a series of bumps the spring will move around a more compressed mean state.

What you are trying to explain is called "Packing" caused by a series of bumps in succession. Has absolutely nothing to do with hitting a speed bump at speed.

 

[drbig]

I agree!

However, the bike gets a case of the shivers when the rear tire gets airborne and touches down before the front. What causes that?

If I understand correctly, its the same effect. The tyre will touch slightly sideways. It spins so it has angular momentum. The impact upsets the axis of rotation of the spinning wheel, so it is forced to move like a spinning top (migration of axis of rotation). But the rear wheel is attached to a bike, so it takes the bike with it!
It is basically a weak form of high-siding.

 

[drbig]

What you are trying to explain is called "Packing" caused by a series of bumps in succession. Has absolutely nothing to do with hitting a speed bump at speed.

Yes you are right, I thought I mentioned that I am only referring to not individual bumps, put what we more commonly experience, which is series of them. Sorry for the misunderstanding.

 

[Jza]

So no ones actually tried those settings?

LMAO

As you seem to have learnt yourself from a book (thus being a well read home tuner) i thought i'd copy in what ive been reading:

Compression damping: This is what gives a bike its feeling of plushness or stiffness, as compression damping determines how fast the suspension can compress when you hit a bump. With stiff compression damping, the fork or shock cannot compress quickly enough when a bump is encountered, and the movement of the wheel as it rises up the face of the bump is transferred into the chassis-where you feel it. With too little compression damping, the weight transfer of the bike itself as you accelerate and brake will be enough to compress the suspension, giving it a Cadillaclike softness.

Rebound damping: Once your suspension has compressed over a bump, rebound damping determines how fast the suspension can extend and keep the wheel in contact with the ground. Too much rebound damping will keep the suspension compressed when it should be extending to follow the road on the downside of a bump, and the wheel will lose contact with the ground. Too little rebound damping and the suspension will extend fast enough to push the bike up forcibly, giving it a loose feeling. Because rebound damping plays such a big part in how well the tire stays in touch with the ground, it gives you the feeling of traction and the confidence that comes with it.

Jza

 

[Jza]

PS Tufbusa... why not contact SportsRider.com and tell them that they are clearly just "home tuners" and to take down the 400 odd bike setups they've posted... obviously these guys (who you dont know but i doubt that matters to you - home tuners the lot of em ) know nothing compared to you and your suspension book...

Whole point of this thread was that the latest settings they posted in a June 2012 edition had changed the settings they posted from back in 2009... and i was interested in feedback from others. Shame you decided to come across as a "bit of a knob"... and get all preachy/judgemental... but thats the ying and yang of this forum i guess

J