Sag measurement results, keen for input.

[flyingbrick]

Hi guys, hope everyone is happy and well.

Finally started doing some kms on my 09 (bought it while I had a broken arm) and it's become very obvious that the rear suspension preload was set far too high. Now I have done this before on dirt bikes without problem but this bike seems odd.

Note, I have reduced rear spring preload drastically to get these numbers. Guessing it was set for a pillion as had zero static sag and about 2mm with me.

Measurements are as follows, measurements are all referenced to the free (unloaded/hanging) sag measurement. All in mm.

Front, static sag = 30. With rider = 33.
Rear, static sag = 15. With rider = 32.

I have a few issues with these numbers.

Firstly, the front seems to have a huge amount of static sag and bugger all rider sag. Just 3mm more once I get on. Secondly, the rear static sag seems a little high, and the loaded sag seems a little low (for road use, but I genuinely have no idea). My research suggests 10mm of thread showing on the rear shock above the nuts is a good starting point. I have about 2mm.

What are peoples thoughts? I wonder if I have a heavier rate rear spring (currently trying to find a stocker)

I weigh 86kg, measurements done without riding gear. Not ideal but will be closer than before!

 

[Bumblebee]

Welcome to the forum, I see your user name is referencing a term from the "Space Cowboys."

As for the sag, I am looking for my base numbers but can't seem to find them at the moment. I'm a little heavier (around 95kg without gear) so my sag numbers will be a bit different.

If you plan on sticking around, perhaps take a swing over to the new members thread and shoot us a couple pictures of the steed...

 

[flyingbrick]

Thanks mate!!

Will vernier my springs wire diameter tonight and compare to a stock one it's just not what I am used to seeing- although it's understandable that sag measurements are likely to operate differently on a sports bike than a dirt bike (the bike weight vs rider weight ratio is vastly different)

Have had this user name for about the past 20 years. When younger I flew radio control airplanes and had one that had a fuselage that resembled a brick.

Cheers, will go to new user area.

 

[ZeePopo]

Hi guys, hope everyone is happy and well.

Finally started doing some kms on my 09 (bought it while I had a broken arm) and it's become very obvious that the rear suspension preload was set far too high. Now I have done this before on dirt bikes without problem but this bike seems odd.

Note, I have reduced rear spring preload drastically to get these numbers. Guessing it was set for a pillion as had zero static sag and about 2mm with me.

Measurements are as follows, measurements are all referenced to the free (unloaded/hanging) sag measurement. All in mm.

Front, static sag = 30. With rider = 33.
Rear, static sag = 15. With rider = 32.

I have a few issues with these numbers.

Firstly, the front seems to have a huge amount of static sag and bugger all rider sag. Just 3mm more once I get on. Secondly, the rear static sag seems a little high, and the loaded sag seems a little low (for road use, but I genuinely have no idea). My research suggests 10mm of thread showing on the rear shock above the nuts is a good starting point. I have about 2mm.

What are peoples thoughts? I wonder if I have a heavier rate rear spring (currently trying to find a stocker)

I weigh 86kg, measurements done without riding gear. Not ideal but will be closer than before!

Seems you are reaching good race sag numbers. I'm running ladden 34f 25 r.

 

[flyingbrick]

Thanks mate.

Using a tutorial for gen1s here on the site I was able to establish that the front was not totally unexpected in sag numbers. Ended up 5.5 turns out on preload which gave 28mm static sag and a total of 40mm laden sag. Bang on 1/3rd travel which I think is going to be good for road riding.

The rear is definately the wrong spring rate. I'm at 28mm laden sag there but can't take out any more preload as out of thread.

 

[Bumblebee]

Have had this user name for about the past 20 years. When younger I flew radio control airplanes and had one that had a fuselage that resembled a brick.

Cheers, will go to new user area.

Cool coincidence to the phrase used on the movie.....

 

[Berlin Germany]

@flyingbrick
welcome to the board
and a lill info aside - for us here in germany your nick means that

loooooooool
was available as 750 or 1000 ccm a looooooooooong time ago
little joke -

now seriously to your gen2 from `09
as we here know, these are bikes that are much too tightly tuned in the chassis. because as soon as you have a co-driver, even if he only weighs 60 kg, the busa becomes a lot much better at cornering.

as we here also know, these are bikes that are much too tightly tuned in the chassis.
because as soon as you have a co-driver, even if he only weighs 60 kg, the busa becomes much better at cornering.
the setting and selection of the spring components - ex works - literally counteracts the age-old wisdom:
only as hard as max. necessary and as soft as possible

the gen1 was already quite tight but the gen2 even surpasses this.
you have the feeling that the damping only takes place via the tires but hardly via the components and that is definitely bad for general handling even on minimally uneven country roads, etc.

 

[RedBull]

flyingbrick

www.hayabusa.org

 

[flyingbrick]

Hi all. I thought I'd bump my old thread here rather than starting a new one.

I'm knocking my o-rings pretty far down the forks and very close to hitting the bump stops. Should I be increasing compression dampening to try reduce this?

 

[sixpack577]

Hi all. I thought I'd bump my old thread here rather than starting a new one.

I'm knocking my o-rings pretty far down the forks and very close to hitting the bump stops. Should I be increasing compression dampening to try reduce this?

Yes, try a quarter or half turn on each fork to start with.
Try to keep the o-rings/zipties roughly an inch above the bottom of the fork legs.

 

[flyingbrick]

thanks mate, will do that!