Static Sag v Rider Sag
Discussion
I understand the difference between the two although not sure how they actually relate to each other in practice.
My understanding is you set the static sag up and the if rider sag is in wrong range you change the spring?
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Is static sag more important? If so ... Why?
My understanding is you set the static sag up and the if rider sag is in wrong range you change the spring?
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Is static sag more important? If so ... Why?
I have no idea but I would have thought it's pointless setting the sag for the rider if it isn't done for the bike first iyswim.
As in the static sag is the first step, no idea why they don't offer doing rider sag afterwards though. Can't be bothered to prop a bike up with a bloke sat on it perhaps?
As in the static sag is the first step, no idea why they don't offer doing rider sag afterwards though. Can't be bothered to prop a bike up with a bloke sat on it perhaps?
Mr OCD said:
I understand the difference between the two although not sure how they actually relate to each other in practice.
My understanding is you set the static sag up and the if rider sag is in wrong range you change the spring?
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Is static sag more important? If so ... Why?
when I get home I'll write you a full dissertation as to why you only need to be concerned about rider sag. static is a useful number but until your bike can ride itself rider sag is more relevant. My understanding is you set the static sag up and the if rider sag is in wrong range you change the spring?
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Is static sag more important? If so ... Why?
And before we start you need to get comfortable with the following. ...
Preload DOES NOT affect spring rates. it ONLY affects ride height...
Think it over and we'll chat later.
bass gt3 said:
when I get home I'll write you a full dissertation as to why you only need to be concerned about rider sag. static is a useful number but until your bike can ride itself rider sag is more relevant.
And before we start you need to get comfortable with the following. ...
Preload DOES NOT affect spring rates. it ONLY affects ride height...
Think it over and we'll chat later.
Legend And before we start you need to get comfortable with the following. ...
Preload DOES NOT affect spring rates. it ONLY affects ride height...
Think it over and we'll chat later.
But aren't most sportsbike shock springs now progressive ... Therefore would affect spring rate?
bass gt3 said:
Mr OCD said:
I understand the difference between the two although not sure how they actually relate to each other in practice.
My understanding is you set the static sag up and the if rider sag is in wrong range you change the spring?
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Is static sag more important? If so ... Why?
when I get home I'll write you a full dissertation as to why you only need to be concerned about rider sag. static is a useful number but until your bike can ride itself rider sag is more relevant. My understanding is you set the static sag up and the if rider sag is in wrong range you change the spring?
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Is static sag more important? If so ... Why?
And before we start you need to get comfortable with the following. ...
Preload DOES NOT affect spring rates. it ONLY affects ride height...
Think it over and we'll chat later.
Just one thing ... If one of those " expert companies" is near Bolton - you may as well get some kid off the street with a four year old bootlace and a teaoon to "measure up and set it" while you trot off round the town for an hour - and return with your £60 or whatever....I have heard some stories before now but only recently had the concrete proof from somebody who used them more than once and asked me to check the settings immediately upon their return ....no two settings matched anywhere and frankly , to my mind , nothing really could have been done to this bike that was in any way close to being set-up. Tread ...and ride with your eyes wide open ...!
Mr OCD said:
But why would two companies who are suspension experts only setup static and make no mention of rider sag?
Probably because once they have sold you new suspension or modified your existing with the correct spring rate then they are assuming that if static sag is correct then so will be rider sag? That and because static is easier to measure, especially if you're on your own...
Mr OCD said:
bass gt3 said:
when I get home I'll write you a full dissertation as to why you only need to be concerned about rider sag. static is a useful number but until your bike can ride itself rider sag is more relevant.
And before we start you need to get comfortable with the following. ...
Preload DOES NOT affect spring rates. it ONLY affects ride height...
Think it over and we'll chat later.
Legend And before we start you need to get comfortable with the following. ...
Preload DOES NOT affect spring rates. it ONLY affects ride height...
Think it over and we'll chat later.
But aren't most sportsbike shock springs now progressive ... Therefore would affect spring rate?
Anyhoo, whilst static sag is a sort of useful number the real pointer is rider sag.
the goal for a road bike is to have 1/3rd of the total suspension stroke taken up in the rider sag. the important part is to get the bike in the ai4 and measure the total suspension stroke. With the front forks you want to set the preload at the 1/3rd to 1/2 from fully out. check if you can pull the forks/front wheel down against the neutral spring. 5mm isn't unusual. this number needs to be included in the overall calculation.
so measure the total stroke.
now get on the bike in all your gear, assume your usual riding position and and measure again. take one from the other and you have your rider sag. if the front forks have a typical 125mm of total stroke look for 30 to 40mm rider sag. same applies to the rear.
if you need to wind in more preload than the halfway point then your springs are on the soft side.
If you just wind in preload to get the right numbers, you might achieve the required sag number but the front will be too soft in the real world. see above about preload not changing spring rates!!
Bass will explain this far more concisely than I can.
On our Motocross race bikes (Honda CRF for starters) the recommended rider sag is between 85mm and 105 mm, that is set with the rider and all his gear on.
The Kawasaki's we have we sent the rear suspension away (as well as a couple of visits to his own workshop with the bikes and rider) to a well known expert in the motocross scene.
He sent us the shockers back that when in use the rear wheel was touching the inside of the rear mudguard and wearing a hole in the tail pipe.
In the end we have changed the rear spring for a harder one 3 times and asked for it to be revolved to our spec with a bigger bump stop.
Rider sag for that is 80mm
When you set rider sag you at first take the weight off the bike in an upright position and measure from 2 set points, I find a bit of masking tape on a panel with a line on works well when measuring from that to a fixed point on say the swing arm.
So you then measure the distance from those 2 points with the bike standing on its own weight then measure the same with the rider and all his gear on, you then adjust the spring until you're in the specified ball park.
Apologies if that doesn't make sense but I am on Morphine and Diazepam tablets.
On our Motocross race bikes (Honda CRF for starters) the recommended rider sag is between 85mm and 105 mm, that is set with the rider and all his gear on.
The Kawasaki's we have we sent the rear suspension away (as well as a couple of visits to his own workshop with the bikes and rider) to a well known expert in the motocross scene.
He sent us the shockers back that when in use the rear wheel was touching the inside of the rear mudguard and wearing a hole in the tail pipe.
In the end we have changed the rear spring for a harder one 3 times and asked for it to be revolved to our spec with a bigger bump stop.
Rider sag for that is 80mm
When you set rider sag you at first take the weight off the bike in an upright position and measure from 2 set points, I find a bit of masking tape on a panel with a line on works well when measuring from that to a fixed point on say the swing arm.
So you then measure the distance from those 2 points with the bike standing on its own weight then measure the same with the rider and all his gear on, you then adjust the spring until you're in the specified ball park.
Apologies if that doesn't make sense but I am on Morphine and Diazepam tablets.
I already have total travel of both forks and shock from handbook so working out correct preload is straight forward enough.
Front - 35-40mm
Rear - 30-35mm
I know that the fork springs on the blade are actually a tiny bit stiff but not far out at all but the shock is soft ... So I think at present the rear is sitting a bit low which is causing the bike to run wide in the power out of bends IMHO.
I'm actually considering a replacement shock as the standard unit isn't great anyway so may just get correct spring for a replacement unit. That's for another discussion.
It's good to know that rider sag is more important which still makes me wonder what these so called suspension 'experts' are playing at...
This is all because I've seen a few suspension setup sheets from some well known tuners that are trusted and my settings on the bike differ quite substantially ... Despite same bike and rider weight ... and my discussions with Ryan who said the same thing about another company.
Hence back to basics I go ...
Front - 35-40mm
Rear - 30-35mm
I know that the fork springs on the blade are actually a tiny bit stiff but not far out at all but the shock is soft ... So I think at present the rear is sitting a bit low which is causing the bike to run wide in the power out of bends IMHO.
I'm actually considering a replacement shock as the standard unit isn't great anyway so may just get correct spring for a replacement unit. That's for another discussion.
It's good to know that rider sag is more important which still makes me wonder what these so called suspension 'experts' are playing at...
This is all because I've seen a few suspension setup sheets from some well known tuners that are trusted and my settings on the bike differ quite substantially ... Despite same bike and rider weight ... and my discussions with Ryan who said the same thing about another company.
Hence back to basics I go ...
Mr OCD said:
I already have total travel of both forks and shock from handbook so working out correct preload is straight forward enough.
Front - 35-40mm
Rear - 30-35mm
I know that the fork springs on the blade are actually a tiny bit stiff but not far out at all but the shock is soft ... So I think at present the rear is sitting a bit low which is causing the bike to run wide in the power out of bends IMHO.
I'm actually considering a replacement shock as the standard unit isn't great anyway so may just get correct spring for a replacement unit. That's for another discussion.
It's good to know that rider sag is more important which still makes me wonder what these so called suspension 'experts' are playing at...
This is all because I've seen a few suspension setup sheets from some well known tuners that are trusted and my settings on the bike differ quite substantially ... Despite same bike and rider weight ...
Hence back to basics I go ...
Sag numbers seem ok if the adjuster isn't wound in. Front - 35-40mm
Rear - 30-35mm
I know that the fork springs on the blade are actually a tiny bit stiff but not far out at all but the shock is soft ... So I think at present the rear is sitting a bit low which is causing the bike to run wide in the power out of bends IMHO.
I'm actually considering a replacement shock as the standard unit isn't great anyway so may just get correct spring for a replacement unit. That's for another discussion.
It's good to know that rider sag is more important which still makes me wonder what these so called suspension 'experts' are playing at...
This is all because I've seen a few suspension setup sheets from some well known tuners that are trusted and my settings on the bike differ quite substantially ... Despite same bike and rider weight ...
Hence back to basics I go ...
as for running wide make sure that your rebound is not too slow. many people have it wound in wAaay too much. you actually want the rebound as fast as possible without the bike bouncing when it springs back. good starting point is wind rebound fully in and back out 2/3rds.
Getting the rider sag correct is by far the most important. You are setting the correct operating point of the suspension to give you adequate compression and rebound range, and to give you the correct nominal fork angle.
Static sag by itself is pretty irrelevant; it is only useful when compared to rider sag, in which case it can give you an idea of whether your spring rate is in the right ball park.
Static sag by itself is pretty irrelevant; it is only useful when compared to rider sag, in which case it can give you an idea of whether your spring rate is in the right ball park.
Mr OCD said:
Well today's job given it's pissing down is to see what settings have been dialed in by my local suspension people ...
If they are out I will be visiting them for a chat.
not having a pop at you but it staggers me why anyone would go to a "suspension" company for anything other than a rebuild. having a complete stranger dial in your bike is like letting the neighbour shag your missus so you can see how it's done! !If they are out I will be visiting them for a chat.
I'm out at the moment faffing around on trials bikes but I'll write up a "how to" later. maybe make it a sticky seeing how often this subject comes up
bass gt3 said:
not having a pop at you but it staggers me why anyone would go to a "suspension" company for anything other than a rebuild. having a complete stranger dial in your bike is like letting the neighbour shag your missus so you can see how it's done! !
I'm out at the moment faffing around on trials bikes but I'll write up a "how to" later. maybe make it a sticky seeing how often this subject comes up
To be fair they set the bike up then asked me to sit on it and then lots of nods all round ... I'm out at the moment faffing around on trials bikes but I'll write up a "how to" later. maybe make it a sticky seeing how often this subject comes up
The bike compresses and rebounds equally front to rear but I reckon shock preload is out at a min...
Regardless got a mate coming over so we can measure rider sag properly:.. I will record ALL the settings down on paper before go any further.
Mr OCD said:
bass gt3 said:
not having a pop at you but it staggers me why anyone would go to a "suspension" company for anything other than a rebuild. having a complete stranger dial in your bike is like letting the neighbour shag your missus so you can see how it's done! !
I'm out at the moment faffing around on trials bikes but I'll write up a "how to" later. maybe make it a sticky seeing how often this subject comes up
To be fair they set the bike up then asked me to sit on it and then lots of nods all round ... I'm out at the moment faffing around on trials bikes but I'll write up a "how to" later. maybe make it a sticky seeing how often this subject comes up
The bike compresses and rebounds equally front to rear but I reckon shock preload is out at a min...
Regardless got a mate coming over so we can measure rider sag properly:.. I will record ALL the settings down on paper before go any further.
I had a suspension clinic with Ryan the other day and i think his head was spinning but in truth it's really simple.
There are 5 main elements to suspension and once you understand their respective roles you'll be off and running.
a big problem is many people associate control with grip. fact is suspension should be compliant enough to allow the tyre to find grip whereas if you have everything too stiff the tyre becomes the suspension and traction suffers.
remember suspension only really matters when you're leaning over. upright you've always got grip but at lean you want the suspension to maintain grip or contact with the road surface. hence it needs a level of compliance and control to achieve this.
Stiff and slow suspension is the enemy even on race bikes. good compliance equals good traction.
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