Help. Adjusting Pre-load / sag the proper way

Doodlefadd

Member
Joined
Dec 30, 2020
Messages
35
Location
Singapore
Hi all,
Long post but,
I've got a few noob question on how do you exactly measure sag. I've been swimming thru the Internet and forum and through too many mechanics locally, to be darn confused now.
And the different terms used depending on region globally, just didn't help.

My riding configurations (if it value-adds the question, I'll just list it)
-2015 non-Es gen 2 s10
-always with pannier, top case, and tank bag.
-front forks stock
-rear shocks ohlins ya013
-don't off road a single bit(wished I could tho, just no place locally to do so, legally)

Measurement enquiries is for solo rider.

For this enquiry, im not gonna use tech terms to avoid confusion to myself and the respondent.

So,
As far as I've learnt, these are the 2 ways to measure proper sag.

1)
- search for the 'free length' of the fork/shocks online/manual and take 30% of that number (a)
-bike on mainstand, wheels off the ground, bike naked (without any boxes/bags), measure. (b)
-bike on ground, rider on, boxes/bags on, measure. (c)
-the difference ( b minus c = a) should be the 30% figure

2)
- bike on mainstand naked, wheels off, measure. (f1/r1)
- bike on ground naked, measure. (f2/R2)
- bike on ground, rider/bags/panniers on, measure (f3/R3)
- formula : R1- [(R2+R3)/2]) = 30-40mm for road use.

My enquiries:
-why is there different ways of calculating the same thing? Is there a preference, or one better than the other?

-is it true that, stock forks free length is 190mm,and ohlins ya013 is 220mm as per manuals? (want to confirm the base value to x 30% from)

-I was told by a mechanic, to loosen all compression and rebound Settings prior to measuring Sag to avoid stiction. I've never seen this advise anywhere else, but when I do measure when both dampening is max loose vs max hard, there is a difference in final value. What should I do exactly?

-also told by another mech that 30mm difference is for road bike. Us adventure bikes have longer suspension travel hence 40mm is the ideal difference to measure for. True?

Suspension gurus alike, I humble request this post be seen, and corrected where wrong.


Thanks for reading too!
 

Doodlefadd

Member
Joined
Dec 30, 2020
Messages
35
Location
Singapore
Have you looked up Dave Moss Tuning online and on YouTube? He seems to be the “go to” person for online help.
Yes I did.
Got more confused coz what he essential did in all his vid is
-measure suspension fully extended (a)
-measure bike on ground with rider (b)
- a minus b = 30-40mm

He essential gave me another way to measure sag.
And I still have some of the listed questions not covered in his yt vids.

Anyone can give a comprehensive, idiot-proof step by step list how to measure them?

Gosh, this is sucha joke at how much I needed spoonfeeding. But the last time the bike felt so good was when it was brand new, and all of us know the stock shocks are badly adjusted from factory. Meddled with it, added more loads aka aftermarket panniers, bags, and handling just went to the realm of unknown for me.
 

bimota

Well-Known Member
Joined
Dec 10, 2017
Messages
2,393
Location
S Wales UK (Bridgend)
Hi all,
Long post but,
I've got a few noob question on how do you exactly measure sag. I've been swimming thru the Internet and forum and through too many mechanics locally, to be darn confused now.
And the different terms used depending on region globally, just didn't help.

My riding configurations (if it value-adds the question, I'll just list it)
-2015 non-Es gen 2 s10
-always with pannier, top case, and tank bag.
-front forks stock
-rear shocks ohlins ya013
-don't off road a single bit(wished I could tho, just no place locally to do so, legally)

Measurement enquiries is for solo rider.

For this enquiry, im not gonna use tech terms to avoid confusion to myself and the respondent.

So,
As far as I've learnt, these are the 2 ways to measure proper sag.

1)
- search for the 'free length' of the fork/shocks online/manual and take 30% of that number (a)
-bike on mainstand, wheels off the ground, bike naked (without any boxes/bags), measure. (b)
-bike on ground, rider on, boxes/bags on, measure. (c)
-the difference ( b minus c = a) should be the 30% figure

2)
- bike on mainstand naked, wheels off, measure. (f1/r1)
- bike on ground naked, measure. (f2/R2)
- bike on ground, rider/bags/panniers on, measure (f3/R3)
- formula : R1- [(R2+R3)/2]) = 30-40mm for road use.

My enquiries:
-why is there different ways of calculating the same thing? Is there a preference, or one better than the other?

-is it true that, stock forks free length is 190mm,and ohlins ya013 is 220mm as per manuals? (want to confirm the base value to x 30% from)

-I was told by a mechanic, to loosen all compression and rebound Settings prior to measuring Sag to avoid stiction. I've never seen this advise anywhere else, but when I do measure when both dampening is max loose vs max hard, there is a difference in final value. What should I do exactly?

-also told by another mech that 30mm difference is for road bike. Us adventure bikes have longer suspension travel hence 40mm is the ideal difference to measure for. True?

Suspension gurus alike, I humble request this post be seen, and corrected where wrong.


Thanks for reading too!
can i ask what spring you have on the ohlins i ask as if you buy a ya013 it comes with a 130 spring, when i bought mine 2 years ago the 130 spring
would be no better than the standard oem shock, because i,m 110kg and wife 75kg plus panniers i had to have a ya013 with a 170 spring

i know a guy about 100kg that rides with panniers loaded had to have a 150 spring

just saying you may have the standard 130 spring it comes with and if your weight plus panniers etc might not be right

rob
 

jrusell

Well-Known Member
Joined
Aug 23, 2017
Messages
404
Location
Dartmouth, Nova Scotia, Canada
Put your bike on the centerstand.
Measure from center of rear axle to a spot on the bike directly above that. Use a piece of tape on the bodywork if that makes it easier.
Write down this number.
For the front measure the chrome showing on the front fork while on the center stand and write this down.

Take the bike off the center stand, sit on it wearing all your normal gear and have your wife or friend measure these 2 points again and write these numbers down.
The normal rule is your sag should be approx. 30% of your suspension travel.
Our travel is 190mm front and rear, so you should be aiming for 57mm front and rear sag. A little bit one way or the other is fine but you should be close to these numbers.

The bike should be setup as you ride it. If you always have topcase, tankbag, and panniers on the bike, then measure it like this.
I have set my bike up as normally ridden and then I load the bike as I would normally have it if I was traveling measure it again and get a second set of preload settings required for this condition.
If I need 2 extra turns of rear preload when fully loaded I just keep this in mind and make this adjustment before I travel.

Backing out compression and rebound setting is a good idea, but really not necessary. Just keep it simple and leave them alone for now.

The tenere forks will be fine and can be adjusted to accomadate almost any weight.
The shock on the Non es and the Es as terribly undersprung.

Sounds like you have a aftermarket shock which is very easy to respring. Let us know your weight and I can tell you what spring you need.
The spring on your ohlins shock has a number printed on it. Post the number and we can tell you the spring rate. Possibly it will work, but most ohlins shocks are sold with much too soft a spring installed.
 

Doodlefadd

Member
Joined
Dec 30, 2020
Messages
35
Location
Singapore
can i ask what spring you have on the ohlins i ask as if you buy a ya013 it comes with a 130 spring, when i bought mine 2 years ago the 130 spring
would be no better than the standard oem shock, because i,m 110kg and wife 75kg plus panniers i had to have a ya013 with a 170 spring

i know a guy about 100kg that rides with panniers loaded had to have a 150 spring

just saying you may have the standard 130 spring it comes with and if your weight plus panniers etc might not be right

rob
I got what everyone else who ordered a new set of ohlins rear got. 130lb springs.
I'm asian, short and featherweight.
80kg with gears Hahaha yea, i prolly get blown away by a breeze.
And yes, thru all the different formulas I've listed I know the 130lb spring is as undersprung as the stock shocks.
Planning to upgrade to higher rated springs, haven't really got to the calculations.

80kg rider,
Plus 3 givi outback aluminium panniers usually loaded about 10kg each?
And a 70kg wife at the back.

That's the daily load I carry.

If it's not too much, care to show where I can go to input these numbers and get the correct spring rate?

Thanks Rob!
FYI, I tried ur 6 clicks out for comp and rebound on the forks suggestions. And that is by far the setting I'm most comfortable with. Tho, my fork setting still doesn't tally with my ohlins rear settings. Haha that's what u get when u have a vague ass. And small arms that can't push the bike effectively to check rebound at stationary, the least.
 

Doodlefadd

Member
Joined
Dec 30, 2020
Messages
35
Location
Singapore
Put your bike on the centerstand.
Measure from center of rear axle to a spot on the bike directly above that. Use a piece of tape on the bodywork if that makes it easier.
Write down this number.
For the front measure the chrome showing on the front fork while on the center stand and write this down.

Take the bike off the center stand, sit on it wearing all your normal gear and have your wife or friend measure these 2 points again and write these numbers down.
The normal rule is your sag should be approx. 30% of your suspension travel.
Our travel is 190mm front and rear, so you should be aiming for 57mm front and rear sag. A little bit one way or the other is fine but you should be close to these numbers.

The bike should be setup as you ride it. If you always have topcase, tankbag, and panniers on the bike, then measure it like this.
I have set my bike up as normally ridden and then I load the bike as I would normally have it if I was traveling measure it again and get a second set of preload settings required for this condition.
If I need 2 extra turns of rear preload when fully loaded I just keep this in mind and make this adjustment before I travel.

Backing out compression and rebound setting is a good idea, but really not necessary. Just keep it simple and leave them alone for now.

The tenere forks will be fine and can be adjusted to accomadate almost any weight.
The shock on the Non es and the Es as terribly undersprung.

Sounds like you have a aftermarket shock which is very easy to respring. Let us know your weight and I can tell you what spring you need.
The spring on your ohlins shock has a number printed on it. Post the number and we can tell you the spring rate. Possibly it will work, but most ohlins shocks are sold with much too soft a spring installed.
Thanks for the reply and the quick formula on how to measure sag Rusell!

2 qns from ur post reply
-when u say bike off mainstand, rider on, GEARS on. Panniers, topcase and tank bag, are gears yes?
-suspension travel for front is 190mm,yeps I see that in all s10 websites for stock forks. I use 190mm as free travel for front.
But my rear are ohlins. Do I use 190mm still or 220mm as stated in ohlins manual as "spring, free length".. If its 190mm,why? (tryna learn the language terms here)

See, sometimes I ask stupid questions like this bcoz I just don't understand the technical terms used.
 

jrusell

Well-Known Member
Joined
Aug 23, 2017
Messages
404
Location
Dartmouth, Nova Scotia, Canada
Thanks for the reply and the quick formula on how to measure sag Rusell!

2 qns from ur post reply
-when u say bike off mainstand, rider on, GEARS on. Panniers, topcase and tank bag, are gears yes?
-suspension travel for front is 190mm,yeps I see that in all s10 websites for stock forks. I use 190mm as free travel for front.
But my rear are ohlins. Do I use 190mm still or 220mm as stated in ohlins manual as "spring, free length".. If its 190mm,why? (tryna learn the language terms here)

See, sometimes I ask stupid questions like this bcoz I just don't understand the technical terms used.
190mm is the suspension travel. Sag is determined by percent of suspension available travel.

If you removed your shock from the bike, then removed the spring from the shock and put the spring alone on the table it would measure 220mm long. This is spring free length completely uncompressed.

When the spring is installed on the shock the spring is compressed and shorter than it's free length. This is called installed length. The difference between free length and installed is called installed preload.
If you put your bike on the center stand so the rear wheel was off the ground, lay under the bike and measure the springs length. This will tell you the installed length or installed preload.
My guess your spring will measure around 205-210mm, with the bike on the center stand.

Installed preload range will usually be between 15-22mm for our bike depending on what rate of spring you have installed.

Ignore the 220mm, use 30% of 190mm.

Most bikes, ours included use a linkage which multiplies the force the spring applies to the rear suspension. Our linkage ratio is averages around 2.9, This means for every mm the shock compresses the wheel moves 2.9mm. You can see from this your shock only compresses 190mm divided by 2.9. Your shock only compresses about 66mm to give you 190mm of travel.
 
Last edited:
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ballisticexchris

Guest
Here is simple specific to any motorcycle:

1) On centerstand write down measurements of both front and rear suspension fully extended. Mark reference points so you measure from same spot for each measurement. Break out owners manual and find out total suspension travel.

2) Put full weight of motorcycle with any gear, bags, full tank of fuel, ready to ride resting full weight on the wheels. Push down slow about a few inches on the seat then pull up slow a few inches on the seat. Let it slowly settle. Take your measurement at reference points. Subtract this from your fully extended measurement. This is your STATIC sag.

3) Gear up ready to ride and sit in your normal riding position on the bike. If you are setting up your suspension for aggressive off road the measure sag while standing. Push down slow about a few inches on the seat then pull up slow a few inches on the seat. Let it slowly settle. Take your measurement at reference points. Subtract this from your fully extended measurement. This is your RIDER sag.

Things to note)

1) Accurate front suspension sag is next to impossible due to both stiction in the forks and the OEM spring design. Yamaha uses progressive dual rate springs on the Super Tenere.

2) Take three or more different measurements with spring preload set at soft, medium, and hard positions. Each of these will give you different measurements.

3) Proper rider sag will be 25%-33% of total travel.

4) After getting your rider sag set re-measure static sag. Too little static sag go up in spring rate. Too much static sag go down in spring rate
 
Last edited by a moderator:
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ballisticexchris

Guest
You are going to find that the Super Tenere is too soft in the rear. The front is pretty darn good stock if setup correctly. IMO Yamaha was smart to use progressive springs up front with outstanding damping to match.
 

Doodlefadd

Member
Joined
Dec 30, 2020
Messages
35
Location
Singapore
You are going to find that the Super Tenere is too soft in the rear. The front is pretty darn good stock if setup correctly. IMO Yamaha was smart to use progressive springs up front with outstanding damping to match.
Thanks for this too Chris!

Reckon I've gotten enough responses to start measuring them proper now.
The race tech bible recommended above sure became my bedtime storybook past few days too!
Will update on the result
 

Jazzer

New Member
Joined
Jun 22, 2015
Messages
27
Location
Tracy, CA
Hi guys,

Here is the stupid question of the day.

Because the stock shock/spring is under sprung, will a more properly sprung shock always raise the height of the bike?

The stock shock works pretty well for me at 160 pounds ( mostly at max preload), but as soon as I add my luggage and camping gear I can barely use the side stand. It would be so nice to be able to just adjust for that.

I really don’t want the bike to grow taller when it’s just me.


thanks
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
3,459
Location
Ventura, CA
When I upgraded my rear spring it improved the lean angle on the side stand slightly, so the answer in my experience is yes.


Sent from my iPhone using Tapatalk Pro
 

Sierra1

Well-Known Member
Joined
Nov 7, 2016
Messages
7,515
Location
Joshua TX
. . . . Because the stock shock/spring is under sprung, will a more properly sprung shock always raise the height of the bike?

The stock shock works pretty well for me at 160 pounds ( mostly at max preload), but as soon as I add my luggage and camping gear I can barely use the side stand. It would be so nice to be able to just adjust for that.

I really don’t want the bike to grow taller when it’s just me.


thanks
I'm assuming that you have a non-ES? 'Cuz, an ES adjusts easily, and quickly. I weigh 300lbs, and have my ES preload at about 55% of max. When my wife rides with me, I set it to max (450lbs is what the bike is rated for). The more preload that I have dialed in, the greater the lean. You can't use the same setting for "just you", as you do when you add all your "stuff".

I understand that everybody has their personal preferences as far as how the bike rides. But, especially at your weight, there's nothing "wrong" with the OE suspension, it's just not your preference. . . . 'cuz, there's plenty of spring. . . . even for my fat ass.
 
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