Suspension tuning for a Hayabusa?

[lowflyn]

hi all , iv got a k6 hayabusa and im starting to fiddle with the suspension as i ride twisty back roads mostly and im sure we all know the conditions of some of our back roads . i did some research and found out that the busa are setup for 75kg riders. i had a giggle to myself as in full leathers im about 100kgs . i put a cable tie round one of the forks to gauge how much travel the suspension was taking up under heavy breaking and discovered they were all but bottoming out. iv got a reasonable understanding of what adjustments do what but all i end up with is a harsh ride and no front end feel or saggy and horrible on the breaks into corners :scratch:,. anyone out there got any hints or tips for me . do i need heavier springs up front or would a heavier grade fork oil be enough ? also has anyone out there tried raising the rear ride height of there busa to help with quicker steering ? any advise or information is welcomed

[Madness]

What profile rear tyre are you running?

[Coldrider]

Needs to sort out suspension both ends before worring about rear ride height, springs at least, then get the correct attitude for designed stability.

[Coldrider]

So the way I read it your springs are too soft, so you are cranking up the compression and rebound to get stability.
The same with the rear, but your weight is causing the rear to drop, so the front end then being higher, won't turn.
Email Dr Rob.

[Madness]

Needs to sort out suspension both ends before worring about rear ride height, springs at least, then get the correct attitude for designed stability.

Ride height is only part of the reason for me asking that question, but you'd already know that, eh?

[lowflyn]

What profile rear tyre are you running?

190-50-17 . i got under 2500km out of a set of bridgestone bt016s so im hoping a proper set up mite help get a couple more kms out of my next set , even tho i know busa eat rubber ,

[Coldrider]

Ride height is only part of the reason for me asking that question, but you'd already know that, eh?yep, measure the circumference of the tyres to see if they make the bike stand higher or lower than standard. but he has hit the nail on the head with soft springs.

[Pussy]

As a matter of interest, what is the current static and rider sag at each end?

[Madness]

190-50-17 . i got under 2500km out of a set of bridgestone bt016s so im hoping a proper set up mite help get a couple more kms out of my next set , even tho i know busa eat rubber ,

Thought so, a 190/50 will always turn slow as fuck compared to a 190/55.

[lowflyn]

So the way I read it your springs are too soft, so you are cranking up the compression and rebound to get stability.
The same with the rear, but your weight is causing the rear to drop, so the front end then being higher, won't turn.
Email Dr Rob.

pretty much and it turns in but im sure it could be better . is the Dr the man to talk to is he ?

[Coldrider]

pretty much and it turns in but im sure it could be better . is the Dr the man to talk to is he ?I am sure he will along soon. If it is any consolation I have a a 2012 BPF blade that needs respringing.

[lowflyn]

Thought so, a 190/50 will always turn slow as fuck compared to a 190/55.

bt016s dont come in 55 which kinda sux cause im a big fan of the bridgys . i thought bout going 65 on the front instead of 70 like iv done on another bike but once again couldnt get it in that range of bridgestone . maybe a brand change mite be on the cards

[lowflyn]

I am sure he will along soon. If it is any consolation I have a a 2012 BPF blade that needs respringing.

is it going to be pricey ? will new valves be involved ?

[lowflyn]

As a matter of interest, what is the current static and rider sag at each end?

il have a measure up and get back to you

[Coldrider]

is it going to be pricey ? will new valves be involved ?Robert Taylor, advertises on this site somewhere, email him and he can give you a price.
Revalving is the next level and maybe worth it, some suspension cannot be reworked, but worth a price at least, and gives you some direction in working towards riding the perfect bike.

i'd do the Michelin PR3

[Pussy]

il have a measure up and get back to you

I myself would start with getting the spring rates right. Then go on to revalving if needed. You might find just getting the springing right will solve your problem.

[SPP]

Email RT

Always set SAG first. Fiddling with damping when spring tension is out is a waste of your time.

If you’re using all of the front travel then it’s more preload or new springs.

Have you watched this fulla? http://www.youtube.com/watch?v=HAWLaLf1Awc

[mulletman]

Yep a Michelin PR2 or 3 with a 55 profile.

[sinfull]

http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

[Stylo]

190-50-17 . i got under 2500km out of a set of bridgestone bt016s so im hoping a proper set up mite help get a couple more kms out of my next set , even tho i know busa eat rubber ,

Getting a good run out of the Metezler Z8's on my second Gen 2 'Busa including a couple days at the drags , you should see 8000 out of the rear , take it easy

[caspernz]

Yep, good value in talking to (and then using the services of) Robert Taylor. Look up KSS (Kiwi Suspension Solutions?) and just adopt the do it once and do it right approach :2thumbsup

[lowflyn]

Email RT

Always set SAG first. Fiddling with damping when spring tension is out is a waste of your time.

If you’re using all of the front travel then it’s more preload or new springs.

Have you watched this fulla? http://www.youtube.com/watch?v=HAWLaLf1Awc

awsome thanks for the link . im trying to do as much as i can myself and that link was very insightful , cant find my tape measure though haha !!:scratch:

[lowflyn]

http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

thanks for the link:niceone:

[lowflyn]

Getting a good run out of the Metezler Z8's on my second Gen 2 'Busa including a couple days at the drags , you should see 8000 out of the rear , take it easy

shit thats alright . never run metezler before but uv got me thinking now . im normally out in the twisties with 600s so its hard work on the tyres keeping up with them through the corners , soon as those straights come into view tho .....:wings: shoulda brought a thou really but ive tasted power and theres no going back now haha

[Robert Taylor]

hi all , iv got a k6 hayabusa and im starting to fiddle with the suspension as i ride twisty back roads mostly and im sure we all know the conditions of some of our back roads . i did some research and found out that the busa are setup for 75kg riders. i had a giggle to myself as in full leathers im about 100kgs . i put a cable tie round one of the forks to gauge how much travel the suspension was taking up under heavy breaking and discovered they were all but bottoming out. iv got a reasonable understanding of what adjustments do what but all i end up with is a harsh ride and no front end feel or saggy and horrible on the breaks into corners :scratch:,. anyone out there got any hints or tips for me . do i need heavier springs up front or would a heavier grade fork oil be enough ? also has anyone out there tried raising the rear ride height of there busa to help with quicker steering ? any advise or information is welcomed

No amount of fiddling with the external clickers and preload or measuring is going to fix that front end for you. Similarly going to a heavier oil is a Heath Robinson ''fix'', all it will do is make the front end ''lazy'' in action and further destroy contact feel and make it harsher.

The first issue is it is undersprung for you and if you do nothing else fitting springs appropriate to your personal statistics will yield a decent improvement. Ohlins make springs to suit, these are more expensive than anything else but they are made to exactly match the standard preload spacer tubes, so you therefore dont have to laboriously calculate preload and cut new preload spacer tubes to suit ( or pay someone a lot of time to do so! )

Going further it is useful to disarm 80% of the travel of the overactive bottoming out cup and piston. This involves cartridge removal. Going further again we have a respec for the front fork cartridges that involves revalving the stock rebound pistons and replacing the base compression pistons with a high flow type and a very specific valving stack. All up brake dive pitch control and chassis composure is improved markedly, with a standout immense improvement in the way abrupt bumps are absorbed.

Yes this all costs money and we arent nor attempt to be the cheapest at such work, but then we also dont cut any corners either.

The Hayabusa responds well to an increase in rear ride height, you can increase the effective shock length by up to 10mm with packers but that is getting pretty sharp, Id go for 6-8mm. Dont do it by pullrods. BUT, you need to get some control over that front end before raising rear ride height!

[SPP]

awsome thanks for the link . im trying to do as much as i can myself and that link was very insightful , cant find my tape measure though haha !!:scratch:

Yeah, all good.

Dave Moss videos are pretty awesome. They cover the very basics without getting too heavy... which is kinda where most people need to start.

After a bit of playing you begin to see some of the possibilities... then the journey down the rabbit hole begins ;)

[Robert Taylor]

Yeah, all good.

Dave Moss videos are pretty awesome. They cover the very basics without getting too heavy... which is kinda where most people need to start.

After a bit of playing you begin to see some of the possibilities... then the journey down the rabbit hole begins ;)

Yes, no amount of external fiddling though is going to compensate for the front end being undersprung and overdamped.