Static Sag v Rider Sag

[bass gt3]

Mr OCD said:

Ok working on this now ...

Rider sag... Does this need to include static sag figure?

Current sag is 34mm at rear with rider on (without taking into consideration static) ...

Front is 23mm ...

Rear sounds ok. Front is much too little. How much preload is wound in?
You can measure static if you want. Make sure you felly extend the suspension front & Rear when you measure. With the front raised up, can you extend the forks slightly by pulling down on the wheel?

[Mr OCD]

ork measurement in air: 124mm
With rider (no kit): 82mm

42mm ...

Shock in air: 620mm
With rider (no kit): 587mm (5th notch)

33mm...

[bass gt3]

Mr OCD said:

ork measurement in air: 124mm
With rider (no kit): 82mm

42mm ...

Shock in air: 620mm
With rider (no kit): 587mm (5th notch)

33mm...

Always the same!! too soft in the front, too hard in the rear. Every Jap bike I've measured is like that.
How much preload in the front?
Do you know what the standard springs are in the Honda??

Edited by bass gt3 on Sunday 29th March 16:34

[Yazza54]

Ah your favourite subject

[Mr OCD]

bass gt3 said:

Always the same!! too soft in the front, too hard in the rear. Every Jap bike I've measured is like that.
How much preload in the front?
Do you know what the standard springs are in the Honda??

Edited by bass gt3 on Sunday 29th March 16:34

11nm rings a Bell... Preload is on standard ...

Just checking rest

[bass gt3]

Mr OCD said:

bass gt3 said:

Always the same!! too soft in the front, too hard in the rear. Every Jap bike I've measured is like that.
How much preload in the front?
Do you know what the standard springs are in the Honda??

Edited by bass gt3 on Sunday 29th March 16:34

11nm rings a Bell... Preload is on standard ...

Just checking rest

double check the 11nm. that's about as hard as they get but your sag numbers don't tally up for such a heavy spring

[Mr OCD]

Front preload - 7 1/4 turns from fully in

Front compression - 3 turns

Front rebound - 1 3/4 turns

[bass gt3]

Mr OCD said:

Front preload - 7 1/4 turns from fully in

Lets ignore Comp & Rebound for now.
So 71/2 turns in from fully closed. Out of how many?? 10? 12?

BTW, preload is taken from fully out
Comp & Rebound taken from fully in

[Mr OCD]

Preload is a pain in ass ...

I've now got the following information and have set the bike up as so ....

Fork measurement in air: 124mm
With rider (no kit): 82mm

Was 42mm ...
Preload - 7 3/4 turns from fully in

Preload - 6 turns turns from fully in
Now 38mm

(Forgot this is measured from fully out and didn't wind out fully so not sure how many turns that is....)

Compression was 3 turns, now 1 3/4 turns
Rebound was 1 3/4 turns now 1 1/4 turns

Rear Shock in air: 620mm

With rider (no kit) 585mm (4th notch)
With rider (no kit): 587mm (5th notch)
With rider (no kit) 590mm (6th notch)

33mm... Set at 5th notch
29mm ... Set at 6th notch (Left here)

Compression ... 2 1/2 turns now 1 1/4 turns
Rebound ... 2 1/4 turns now 1 turn

So ... 38mm front, 29mm rear making assumption wearing kit will increase to roughly 40mm front, 30mm rear means preload is in right range.

I have too much time on my hands

[bass gt3]

Mr OCD said:

Preload is a pain in ass ...

I've now got the following information and have set the bike up as so ....

Fork measurement in air: 124mm
With rider (no kit): 82mm

Was 42mm ...
Preload - 7 3/4 turns from fully in

Preload - 6 turns turns from fully in
Now 38mm

(Forgot this is measured from fully out and didn't wind out fully so not sure how many turns that is....)

Compression was 3 turns, now 1 3/4 turns
Rebound was 1 3/4 turns now 1 1/4 turns

Rear Shock in air: 620mm

With rider (no kit) 585mm (4th notch)
With rider (no kit): 587mm (5th notch)
With rider (no kit) 590mm (6th notch)

33mm... Set at 5th notch
29mm ... Set at 6th notch (Left here)

Compression ... 2 1/2 turns now 1 1/4 turns
Rebound ... 2 1/4 turns now 1 turn

So ... 38mm front, 29mm rear making assumption wearing kit will increase to roughly 40mm front, 30mm rear means preload is in right range.

I have too much time on my hands

The key here ( which you're missing ) is to understand the number of turns/clicks as a factor of total available.
For example, if there's 6 turns of rebound on the front fork, I'd bet 1 1/2 from full in is way too slow. If however it's out of 2, then it might be about right.
Preload ONLY ADJUSTS RIDE HEIGHT, (repeat this 1000 times!!) So adding preload might give you the sag you're looking for, but if the spring is fundamentally too light, the bike still won't be right. Add to that you'll just be raising the front making the bike slower to steer and hold it's line on corner exit.
Maybe tomorrow speak with someone from K-Tech or similar and confirm what the standard springs are from the factory.
If the springs aren't right, nothing you do to compression, rebound, preload air gap or whatever will cover up for the fact.
On your bike for road use and occasional track I'd be wanting to achieve 35mm front AND rear. You seem to be winding the notches in reducing sag in the rear and making it overly stiff.

So given you know you have 124mm of total travel in the front and xxx in the rear, make a note of available adjustments and lets see what we can do. If you're measuring without gear I'd be a cautious as you'd be surprised the difference kit makes

[theshrew]

Get your kit on when measure it you noddy.

If you need a hand give a shout and we can do mine properly at the same time.

Edited by theshrew on Sunday 29th March 19:15

[Mr OCD]

Bloody hell... talk about going round in circles ... Wish hadn't bothered buggering about now

Spring rates:

Front - 1.1kg/mm

Rear - 11.2kg/mm

I'm not crawling around on floor adjusting st in my bike kit ... Sod that.

Travel of fork is more than the shock so why the same measurements? I've always set my bikes up to have more at front than rear.

[Mr OCD]

Sorry missed some info ...

Range Info:

Fork preload - 15 turns
Fork comp - 3 1/4 turns
Fork rebound - 3 1/4 turns

Shock preload - 10 clicks
Shock comp - 4 1/4 turns
Shock rebound - 3 1/4 turns

Edited by Mr OCD on Sunday 29th March 20:26

Edited by Mr OCD on Sunday 29th March 20:29

[bass gt3]

Mr OCD said:

Bloody hell... talk about going round in circles ... Wish hadn't bothered buggering about now

Spring rates:

Front - 1.1kg/mm

Rear - 11.2kg/mm

I'm not crawling around on floor adjusting st in my bike kit ... Sod that.

Travel of fork is more than the shock so why the same measurements? I've always set my bikes up to have more at front than rear.

Hahaha

Rear sag should be measured at a point directly above the rear axle. You are doing it there yes?? Rear suspension will have the same travel as the front give or take a few mm so the sag measurements at the axles is critical. Don't forget the rear is operated through a lever system so if you measure anywhere other that at the axle you'll get misleading numbers.
I'm amazed at the 1.1kg/mm number, that equates to a 10.7N spring which is pretty heavy. Yet your sag numbers seem high for such a stiff spring. but again, until you can say it's 6 turns out of ?? it's difficult to say. A good reckoning is 1 turn of preload equates to 1mm of ride height, and most forks have around 10 turns available.
The goal is to get the bike balanced on its suspension. Soft in the front and hard in the back will unsettle it and not feel nice. Better to get equal sag front and rear, so the bike reacts equally at it's centre of gravity, rather than pitching more fore or aft. Try pushing down sharply on the bike just behind the filler cap. It should compress cleanly and equally front and rear, and come back up smartly, again with no delay in either end. If it's rocking, with one end going down more than the other, or coming back up more slowly, adjust the sag until you achieve balance, even if it's slightly outside the optimum numbers.
And as much as you might not like it, it's important to measure and set the sag in your FULL gear.

Next week, tune it as we discuss Compression and Rebound damping......

Edited by bass gt3 on Sunday 29th March 20:29

Edited by bass gt3 on Sunday 29th March 20:30

[Mr OCD]

Range Info:

Fork travel - 120mm
Fork preload - 15 turns
Fork comp - 3 1/4 turns
Fork rebound - 3 1/4 turns

Shock travel - 135mm
Shock preload - 10 clicks
Shock comp - 4 1/4 turns
Shock rebound - 3 1/4 turns

Edited by Mr OCD on Sunday 29th March 20:34

Edited by Mr OCD on Sunday 29th March 20:45

[bass gt3]

Mr OCD said:

Mr OCD said:

Sorry missed some info ...

Range Info:

Fork preload - 15 turns
Fork comp - 3 1/4 turns
Fork rebound - 3 1/4 turns

Shock preload - 10 clicks
Shock comp - 4 1/4 turns
Shock rebound - 3 1/4 turns

Edited by Mr OCD on Sunday 29th March 20:26

Edited by Mr OCD on Sunday 29th March 20:29

So you've slowed your rebound damping down by closing it to 1 1/2 turns??
Unless you can say why, I'd question that. Too slow rebound is one of the worst conditions suspension can be afflicted with. 90% of peeps seem to slow it down much too much yet don't understand why it's so important.
Bottom line is you need the rebound as FAST as possible but only to a point where the fork or shock rises then settles, rather than bounces or oscillates.
Also, i'd be wary of setting the comp or rebound unless you've been out on the bike for 30-60 mins and the suspension is warmed up.

[wc98]

too much rebound damping will bite on very bumpy roads, suspension unable to recover to absorb next bump quick enough. bass gt3 ,do you find a big difference between the kit used by different japanese manufacturers ? i noticed a big difference in feel going from suzuki to honda .

[Mr OCD]

bass gt3 said:

So you've slowed your rebound damping down by closing it to 1 1/2 turns??
Unless you can say why, I'd question that. Too slow rebound is one of the worst conditions suspension can be afflicted with. 90% of peeps seem to slow it down much too much yet don't understand why it's so important.
Bottom line is you need the rebound as FAST as possible but only to a point where the fork or shock rises then settles, rather than bounces or oscillates.
Also, i'd be wary of setting the comp or rebound unless you've been out on the bike for 30-60 mins and the suspension is warmed up.

Half tempted to put it back as it was now mate ... I'm using the bike daily and clearly my logic and understanding is not enough to set the bike up properly.

I got the compression and rebound settings from the CBR forum, which seem to match suspension setups from several companies over here ... Except mine which I'm questioning ...

Given the rear shock has too little sag for its travel I'm going out to reduce that down to notch 4, which is about 35mm ...

I thought winding in the comp and rebound hardens the suspension and therefore makes it faster not slower.

Confused!

[bass gt3]

wc98 said:

bass gt3 ,do you find a big difference between the kit used by different japanese manufacturers ? i noticed a big difference in feel going from suzuki to honda .

Not really TBH. It's all much of a muchness.
I did an experiment with a brand new ZX10 shock in terms of valving response vs temperature that was pretty eye opening.
There's also quite a narrow range that the valving is actually effective. So if there's 10 clicks, it's really only clicks3 to 7 that are any good.
As for rebound, you're right about it not recovering and such, but think of it this way. The purpose of the rebound damping is to allow the spring to force the tyre into the road to follow surface contours. If the rebound is too slow, when the rear drops into a depression, or comes off of a small irregularity, the tyre doesn't effectively maintain contact hence affecting grip. This can result in the rear packing down as it is successively compressed by bumps until the rear suspension becomes solid, at which point the tyre now is the only suspension left. This is not good thing!!

[Mr OCD]

So just to reiterate to avoid further confusion!

Fork preload 9 turns in from fully out of a total of 15 turns (so I have raised the ride height slightly)

Fork compression 1 3/4 turns from fully in from a total of 3 1/4 turns (made stiffer)

Fork rebound 1 1/4 turns from fully in from a total of 3 1/4 turns (made stiffer)

Shock preload on setting 6 of 10 ... So I've raised ride height at rear as well)

Shock compression now 1 1/4 turns from fully in from total 4 1/4 turns. (Made stiffer)

Shock rebound now 1 turn from fully in from total of 3 1/4 turns (made stiffer)...

So you can see I've increase compression and rebound both front and rear and also raised both ends slightly as well...

This is hard work