Static Sag v Rider Sag

[Mr OCD]

So come on Bass ... What am I changing ... More input!

[bass gt3]

Mr OCD said:

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!

Ok, think of it like this. Turning a valve, comp or rebound clockwise is like closing a tap. Righty tighty! So as you turn it, the orifice closes, which means there's a smaller hole for the oil to pass through. The slower it travels, the slower the damping response. Conversely, opening the valve allows the oil to travel faster hence the damping acts quicker.
PLEASE don't copy settings from some forum, only you can determine what's right for you and your bike. It really isn't difficult, but as a start, set the sag so you achieve balance front and rear.
Think of it like this.....
A springs job is to keep the tyre in contact with the road surface. But a spring is an uncontrolled device so if you deflect it, it will oscillate until the energy is dissipated.
Now the compression and rebound damping are designed to control the springs reaction, converting the energy to heat insofar as the oil it uses. So if the compression damping is too hard, or slow, when the wheel hits a bump, the fork won't react but the force will be transmitted to the bike making the front jump up. Not what we want. But if the damping is too fast, that same bump will make the fork compress too much, again making the wheel come off the ground.
Now rebound controls the return of the spring. Too slow, and if you go over a depression, or as the wheel comes over the back of a bump, it won't follow the road surface and now the wheel is hanging in the air. Likewise, if the rebound is too fast, it'll push the wheel back down, but with too much energy making the wheel bounce back up and off the ground again. Not good either.
But the truth is too slow is much worse than too fast. Too slow causes the suspension to be packed down as it absorbs the bumps but it can't return to normal so it gets harder and harder until it stops working.
This could manifest itself in people thinking they need to raise the rear as the bike runs wide on corner exit. But it's not a ride height issue per se, rather the still compressed rear shock is keeping the rear down making turning more difficult and prone to running wide. All because the rebound is too slow.

[bass gt3]

Mr OCD said:

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)

Regardless, what's the sag number?????

Mr OCD said:

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

Sounds ok but I'd start at a faster base setting

Mr OCD said:

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

Not liking this AT ALL!! Too slow, should be around the 21/2 turns out mark when warm BUT MUST BE PROVEN WITH THE BOUNCE TEST

Mr OCD said:

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

Regardless, whats the sag number above the rear axle? Does it match the front??

Mr OCD said:

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

Might be a tad stiff, try opening it a little

Mr OCD said:

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

Nope, way too slow. See above!

Mr OCD said:

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

I can't comment on the compression, but I'd bet your rebound is much too slow. You need to get it all warmed up and check it. The rebound needs to be as fast as possible without the bike double bouncing when you test it.

Mr OCD said:

This is hard work

Nahh, you're making it hard

Edited by bass gt3 on Sunday 29th March 21:21

[Mr OCD]

Ok, before shoot to garage ...

Rear sag currently - 29mm

Front sag currently - 38mm

It doesn't help that Honda call everything harder > softer !!!

I'm going to increase rear sag to 35mm now.

[bass gt3]

Mr OCD said:

Ok, before shoot to garage ...

Rear sag currently - 29mm

Front sag currently - 38mm

It doesn't help that Honda call everything harder > softer !!!

I'm going to increase rear sag to 35mm now.

Cool, try bouncing the bike from right behind the filler cap. It should compress equally, that's a good indication. You might need to twiddle the comp adjusters to get there, butonly do it once you've ridden for a min of 30 mins
When adjusting valves, just remember Righty Tighty,Lefty Loosey.
And open those rebound adjusters!!! They're way too closed!!!!

[Mr OCD]

Rear sag now on 35mm ... Do I need more?

That's on notch 4 of 10...

Opening rebound now as proper slow rising ...

[Mr OCD]

Rebound front is now 1 3/4 turns

Rebound rear is now 2 1/4 turns

Bounces back up properly lol

[bass gt3]

Mr OCD said:

Rear sag now on 35mm ... Do I need more?

That's on notch 4 of 10...

Opening rebound now as proper slow rising ...

Don't worry about what notch, just try to get the front and back about the same. If we were changing springs it's be a different matter but we have to work with what we have.
Trust me on the rebound, it needs to be FAST without oscillating or double bouncing. But remember the oil is cold and viscous so the shock and forks will move more slowly. Check it after your ride to work or back home.
You can then adjust the compression damping to slow the initial response of the forks/shock if it gets a bit wooly.

ps, who do I send my invoice to???

[bass gt3]

Mr OCD said:

Rebound front is now 1 3/4 turns

Rebound rear is now 2 1/4 turns

Bounces back up properly lol

Remember that if it's all cold, the damping will speed up as the oil warms and thins. But make sure you keep the rebound as fast as possible. I'd still wager you should be at 2 to 2 1/4 from fully in
Maybe checkout the Dave Moss vids to see what I mean. Rebound is your most important adjustment so set it and LEAVE IT ALONE!!!

[Mr OCD]

bass gt3 said:

Remember that if it's all cold, the damping will speed up as the oil warms and thins. But make sure you keep the rebound as fast as possible. I'd still wager you should be at 2 to 2 1/4 from fully in
Maybe checkout the Dave Moss vids to see what I mean. Rebound is your most important adjustment so set it and LEAVE IT ALONE!!!

Interesting that I got a settings from Dave Moss as per so ...



Fiddling now ... lol

[theshrew]

bass gt3 said:

Don't worry about what notch, just try to get the front and back about the same. If we were changing springs it's be a different matter but we have to work with what we have.
Trust me on the rebound, it needs to be FAST without oscillating or double bouncing. But remember the oil is cold and viscous so the shock and forks will move more slowly. Check it after your ride to work or back home.
You can then adjust the compression damping to slow the initial response of the forks/shock if it gets a bit wooly.

ps, who do I send my invoice to???

Sounds like a silly question but how do you know you are getting the rebound correct. I know what it should do, however surely how hard you push down and if you realise it at the correct point would alter the results a lot from person to person. What would you feel while your riding if its out ?

Presumably how old the fork oil is effects things a lot to ? Is it a std oil or can you buy different viscosity fork oil ?

[bass gt3]

Mr OCD said:

bass gt3 said:

Remember that if it's all cold, the damping will speed up as the oil warms and thins. But make sure you keep the rebound as fast as possible. I'd still wager you should be at 2 to 2 1/4 from fully in
Maybe checkout the Dave Moss vids to see what I mean. Rebound is your most important adjustment so set it and LEAVE IT ALONE!!!

Interesting that I got a settings from Dave Moss as per so ...



Fiddling now ... lol

Problem with a blanket approach, without proving it on your bike, you can't be 100% if it's right.
I'm not keen on the preload comment, as he seems to be using it as a means of jacking up the rear, hence the comment about the 60 profile tyre being a benefit.
Given the choice, I'd make sure the sag is right then pull the forks through a few mm if it's still slow to turn.
As for rebound, keep fiddling until it's too fast, where the bike bounces backup and rather than settle and stop, it maybe bounces again slightly. But again, if you're working on cold suspension, you can only really tell once you've ridden and everything is warm

[Mr OCD]

Right so this is where I'm at ...

Front sag - 38mm
Rear sag - 35mm

Front rebound - 1 3/4 turns
Front comp - 1 3/4 turns

Rear rebound - 2 1/4 turns
Rear comp - 2 1/2 turns

Got to be honest it no longer feels balanced anymore although rebounds fine.

Rear feels soft as hell ... Front feels hard. So guess need to play with compression

[bass gt3]

theshrew said:

bass gt3 said:

Don't worry about what notch, just try to get the front and back about the same. If we were changing springs it's be a different matter but we have to work with what we have.
Trust me on the rebound, it needs to be FAST without oscillating or double bouncing. But remember the oil is cold and viscous so the shock and forks will move more slowly. Check it after your ride to work or back home.
You can then adjust the compression damping to slow the initial response of the forks/shock if it gets a bit wooly.

ps, who do I send my invoice to???

Sounds like a silly question but how do you know you are getting the rebound correct. I know what it should do, however surely how hard you push down and if you realise it at the correct point would alter the results a lot from person to person. What would you feel while your riding if its out ?

Presumably how old the fork oil is effects things a lot to ? Is it a std oil or can you buy different viscosity fork oil ?

You need to compress the suspension, front or back with enough force that it comes back a significant amount. You can see if it's returning slowly, or if it's overly fast and not controlling the spring. Takes a bit of practice but you'll get the hang.
As for fork oil, yes, it degrades with time. You'd be amazed how much crud gets into the forks and contaminates the oil. Ohlins recommend oil changes every 20 hours so take from that what you will
As for the oil, typically you want 5 weight, as it maintains its viscosity better. Heavier oils will thin more as they warm giving a broader range of damping response vs temperature. You can get 2.5 weight but that might be too thin for the UK

[clen666]

Just to thread hijack - I have 'TEN' punched on the top of each of my forks (on the preload adjusters).

Nothing was mentioned about this when I bought the bike so I can only assume that this relates to the spring fitted, TEN being 10N/mm?

[Mr OCD]

bass gt3 said:

Problem with a blanket approach, without proving it on your bike, you can't be 100% if it's right.
I'm not keen on the preload comment, as he seems to be using it as a means of jacking up the rear, hence the comment about the 60 profile tyre being a benefit.
Given the choice, I'd make sure the sag is right then pull the forks through a few mm if it's still slow to turn.
As for rebound, keep fiddling until it's too fast, where the bike bounces backup and rather than settle and stop, it maybe bounces again slightly. But again, if you're working on cold suspension, you can only really tell once you've ridden and everything is warm

The bike is used every day hence trying to establish a base setting from what I can tweak ... I can then warm it on way to work and tweak at each destination

[bass gt3]

Mr OCD said:

Right so this is where I'm at ...

Front sag - 38mm
Rear sag - 35mm

Front rebound - 1 3/4 turns
Front comp - 1 3/4 turns

Rear rebound - 2 1/4 turns
Rear comp - 2 1/2 turns

Got to be honest it no longer feels balanced anymore although rebounds fine.

Rear feels soft as hell ... Front feels hard. So guess need to play with compression

Try slowing the rear comp or opening the front comp to get better balance. Remember that compression adjustment will only affect the SPEED of change not the amount.

[bass gt3]

clen666 said:

Just to thread hijack - I have 'TEN' punched on the top of each of my forks (on the preload adjusters).

Nothing was mentioned about this when I bought the bike so I can only assume that this relates to the spring fitted, TEN being 10N/mm?

No, TEN means TENSION. Rebound in other words
Apart form Big Piston Forks or separate leg items like newer Yams, Preload and Rebound are at the top of each leg, Compression is at the bottom

[theshrew]

bass gt3 said:

theshrew said:

bass gt3 said:

Don't worry about what notch, just try to get the front and back about the same. If we were changing springs it's be a different matter but we have to work with what we have.
Trust me on the rebound, it needs to be FAST without oscillating or double bouncing. But remember the oil is cold and viscous so the shock and forks will move more slowly. Check it after your ride to work or back home.
You can then adjust the compression damping to slow the initial response of the forks/shock if it gets a bit wooly.

ps, who do I send my invoice to???

Sounds like a silly question but how do you know you are getting the rebound correct. I know what it should do, however surely how hard you push down and if you realise it at the correct point would alter the results a lot from person to person. What would you feel while your riding if its out ?

Presumably how old the fork oil is effects things a lot to ? Is it a std oil or can you buy different viscosity fork oil ?

You need to compress the suspension, front or back with enough force that it comes back a significant amount. You can see if it's returning slowly, or if it's overly fast and not controlling the spring. Takes a bit of practice but you'll get the hang.
As for fork oil, yes, it degrades with time. You'd be amazed how much crud gets into the forks and contaminates the oil. Ohlins recommend oil changes every 20 hours so take from that what you will
As for the oil, typically you want 5 weight, as it maintains its viscosity better. Heavier oils will thin more as they warm giving a broader range of damping response vs temperature. You can get 2.5 weight but that might be too thin for the UK

Thanks. I will look into what sort of a job it is to change it then. Might aswell do it correctly if im going to do it.

[clen666]

bass gt3 said:

No, TEN means TENSION. Rebound in other words
Apart form Big Piston Forks or separate leg items like newer Yams, Preload and Rebound are at the top of each leg, Compression is at the bottom

Ah I see, that's a shame as according to the race tech suspension website, 10N/mm would be pretty much bang on what is recommended for my weight (according to their calculator).