Sag questions

[LogoMan]

Just checked the sag on my front forks. I put a cable tie on one of the fork tubes and did the measurements starting with the forks fully extended.

Sag with weight of the bike only: 1-7/8"

Sag with rider: 2-1/4"

Forks "fully" compressed: 3-5/8" (I held the front brake lever while on the bike and bounced the bike up and down to measure this.)

I'm not sure, but I have a feeling that I need stiffer springs if it sags that much and only leaves 1-3/8" or so of travel with me on board.

What say you all?

I'm probably 215-220 lbs. with gear on. The spring on the rear shock is 1.1 I believe.

[HANKSXXX]

You can't acurately measure total fork (wheel) travel that way.

IIRC, front travel is 4.3"

You do have to much sag in the front.

What fork springs are currently installed?

How much sag in the rear?

Do you mean rear spring rate is 1100 lbs?

[02 SilverBird]

Randy a long time ago I was looking into this and there was a very good post on how to check it correctly. One guy said there was a very cheap option as opposed to buying new spring's,it was to get some washer's the correct dia as tube 2/3mm thick and ad on top of spring to increese tension. He said it worked well for him and its a cheap and easy test. Rob

[xrated]

That is way too much sag on the front forks. Normally, the ideal amount of loaded sag (you on the bike with whatever gear you would normally wear) is roughly 1/3 of the fork travel. If for example you have 4.8 inches of fork travel, that would equate to 122 to 123 millimeters of travel. Divide that number (123) by 3 and you come up with 41mm of loaded sag.

My trackbike, which is set up with Ohlins internals in the front and an Ohlins TTX shock in the rear have the following numbers: Front loaded sag: 38mm Rear loaded sag: 25mm. Keep in mind that this is a track bike and normally, most folks like a street bike set up with a little less stiff suspension setup. Your best bet in my opinion would be to change out the springs in the front forks and get some that are suited to you riding style/weight. Change the fork oil while you are in there and if necessary, the fork seals. Hope this helps.

[Para045]

One guy said there was a very cheap option as opposed to buying new springs,it was to get some washer's the correct dia as tube 2/3mm thick and ad on top of spring to increase tension. He said it worked well for him and its a cheap and easy test. Rob

That's OK for small changes to increase preload but wont help if the springs are way too light, all it really is doing is reducing suspension travel and more likely to bottom out quicker IMHO

That is way too much sag on the front forks. Normally, the ideal amount of loaded sag (you on the bike with whatever gear you would normally wear) is roughly 1/3 of the fork travel. If for example you have 4.8 inches of fork travel, that would equate to 122 to 123 millimetres of travel. Divide that number (123) by 3 and you come up with 41mm of loaded sag.

Yeah everything I've read suggests around 35-38mm (1 3/8"-1 1/2") :icon_think: From your weight the stock springs would be a little light :icon_think:

Type of Riding: Street

Rider Weight (without gear): 218 lbs

Bike Weight (semi-wet): 492 lbs

FRONT FORK SPRINGS

Recommended Fork Spring Rate for Street: 1.108 kg/mm

Stock Fork Spring Rate: .890 kg/mm

From memory the 1100lb spring on the shock is ~ 19.6 kg/mm so a fraction heavy for you

REAR SHOCK SPRING

Recommended Rear Shock Spring Rate for Street: 17.95 kg/mm

Stock Shock Spring Rate: 16.8 kg/mm

[LogoMan]

Thanks guys.

I had Cogent set the rear up a bit stiff. It really doesn't feel bad. Could maybe dial in a bit more rebound damping but that's it. Cogent just rebuilt the shock.

I just changed the fork fluid. Put SS-7 in there. Seals are fine.

Any suggestions for a source/brand of fork springs? I have straight rate springs in there now. I've heard conflicting things about some popular suppliers. Heard good things about the JAWS springs. Not sure if it's worth the trouble of ordering those, though.

[Para045]

I too have heard good things of the Jaws springs but they don't make them heavy enough for me @~ 300lb's, a lot of the others like Racetech are the same

I ended up getting Sonic Springs as they were the only ones who had anything over 1.1kg/mm :icon_think: They were listed as ST1100 springs back then but they are the same size

[LogoMan]

I too have heard good things of the Jaws springs but they don't make them heavy enough for me @~ 300lb's, a lot of the others like Racetech are the same

I ended up getting Sonic Springs as they were the only ones who had anything over 1.1kg/mm :icon_think: They were listed as ST1100 springs back then but they are the same size

Is $80/spring a good price? I see they have 1.1's as you recommended for my weight.

[Redbird]

Type of Riding: Street

Rider Weight (without gear): 218 lbs

Bike Weight (semi-wet): 492 lbs

Keep in mind Race Tech's calculator uses the manufacture's claimed weight a lot of the time. It'd be a good idea to change that to something more realistic before calculating/purchasing. The actual number should be somewhere above 525 lbs., depending on what the hell they mean by "semi-wet".

[EVLXX]

So Here's what I come up with after going to the RaceTech calculator.

97-03 Honda CBR1100XX

1. Type of Riding:

Street

2. Rider Weight (without gear): 220 lbs

3. Bike Weight (semi-wet): 550 lbs

Note: Bike Weight is critical for Road Race applications where significant amounts of weight have been removed.

It is common for a race ready sport bike to be 25 to 50 lbs less than displayed.

Rider Weight: 220 lbs.

Bike Weight: 550 lbs.

FRONT FORK SPRINGS

Recommended Fork Spring Rate for Street: 1.198 kg/mm (use closest available)

Stock Fork Spring Rate: .890 kg/mm (stock)

Available FRSP S3732 Series Springs are:

Part Number

Description

Price Select to Buy

FRSP S3732120 RT FRK SPR 36.7x34.5x315 1.2kg $119.99

REAR SHOCK SPRING

Recommended Rear Shock Spring Rate for Street: 18.00 kg/mm (use closest available)

Stock Shock Spring Rate: 16.8 kg/mm (stock)

Available SESP 90225 Series Springs are:

Part Number

Description

Price Select to Buy

SESP 902251000 SK SPRING 9.0 x 2.25" 18.0kg $119.99

Discontinued ( I called )

Now note that I changed the semi-wet bike weight to 550 lbs. why you might ask. Well there's a multi-layered answer to that. First off doesn't our XX weigh in at about 552 lbs wet. I think so. And gasoline weighs in at about 6.1 lbs per gallon. So if I subtract 15 pounds for 2.5 gallons of gas, then start playing with the calculator I find out I'm really close to a 18 kg rear spring. So I added back a few pounds and low and behold I hit 18 kg exactly.

Now since I would want a balanced system, it looks like to me anyways, that the best match to the 18Kg rear, would be a 1.2 Kg front.

What say you ? (anybody)

And just for arguments sake, I went and found some Information Sources...

http://wiki.answers.com/Q/Which_is_heavier...ter_or_gasoline

http://www.motorcycle.com/shoot-outs/honda...1200-15400.html

[tomek]

It is all academic discussion.

Race Tech springs are black in colour,I don`t think he would want them anyway.

Stock front springs are almost of correct rate for that weight range,you can`t take those calculators too seriously.

1.2 would be waaaaaaaaaay too stiff.

[Redbird]

1.2 would be waaaaaaaaaay too stiff.

Agree completely. I had 1.0s on my XX when I was around 220lbs w/o gear. They were a little light, but close. 1.05s would have been perfect for me at that weight.

Stock is .89, so that is closer to what you'd need than 1.2s, which would be stupid stiff for your weight.

[redxxrdr]

Randy,

You had Cognet do the rear, do you have the funds to have them do the front?

I felt a big change with my Cognet front forks. SAG was right at 36mm for my 200 lb rider weight.

I remember that they used race tech valving and a proprietary spring to fit my weight.

The biggest problem I have is that I am not a good enough rider to know if the ride changed for the good, or just changed.

It certainly smooths out the bumps and ripples.

I plan to get some of our experts to give my bike a try this year at RacerXX.

Yet another reason to show up at Jennings.

[HANKSXXX]

Thanks guys.

I had Cogent set the rear up a bit stiff. It really doesn't feel bad. Could maybe dial in a bit more rebound damping but that's it. Cogent just rebuilt the shock.

I just changed the fork fluid. Put SS-7 in there. Seals are fine.

Any suggestions for a source/brand of fork springs? I have straight rate springs in there now. I've heard conflicting things about some popular suppliers. Heard good things about the JAWS springs. Not sure if it's worth the trouble of ordering those, though.

Cogent did the rear, right?

Why not get the front springs from them too?

I believe he has the springs made longer than stock and possibly even longer than Jaws.

As far as sag specs go, I run 44mm front and 34mm rear.

That's with an 1100 lb spring on the Penske and 1.0's in the front. I weigh 195-200 lbs.

[EVLXX]

1.2 would be waaaaaaaaaay too stiff.

Agree completely. I had 1.0s on my XX when I was around 220lbs w/o gear. They were a little light, but close. 1.05s would have been perfect for me at that weight.

Stock is .89, so that is closer to what you'd need than 1.2s, which would be stupid stiff for your weight.

T, ?

Did you have to preload the springs ?

If yes, and if you can recall correctly, how big was your spacer ?

...

Now, Since talking in Kg's is like talking in Greek to me I'll convert to pounds and inches.

Speaking of fork springs,

0.89 kg/mm is equal to 50.34 lbs/in.

1.0 kg/mm = 56.57 lbs/in.

1.1 kg/mm = 62.22 lbs/in.

1.2 kg/mm = 67.88 lbs/in.

The Stock rear spring is a,

16.8 kg/mm = 950.37 lbs/in.

and a 18 kg/mm = 1018.26 lbs/in.

so......

I read this as a 68 lbs/in increase in the rear which would need to be divided by the leverage angles in the rear's suspension (which I don't know). You would then arrive at a number that would represent lbs/in of travel. Which could then be compared to the front end.

Now, IF the ratio of rear shock travel is 1:2 ( one inch of shock compression for ever inch of wheel travel) then the 1.2 kg/mm fronts would give you an increase of 35.08 lbs./in of travel.

68 divided by 2 = 34.

34 compared to 35.08.... hmmmm, I'd say that's pretty close.

Now the real question is.... is the math above relevant to the Bird ? What is the rear springs ratio of compression - to - wheel travel ?

[EVLXX]

As far as sag specs go, I run 44mm front and 34mm rear.

That's with an 1100 lb spring on the Penske and 1.0's in the front.

WHY ?

Why do you run your bike out of balance ? I have never set up any bike, street or dirt, I owned out of balance. It the Dirt Bike world, that much of a difference is the difference between going over the Bars and stay level in the air, crashing and Landing smooth and fast.

I would think the same relates to the street...... well................ it always has for me anyway.

[HANKSXXX]

As far as sag specs go, I run 44mm front and 34mm rear.

That's with an 1100 lb spring on the Penske and 1.0's in the front.

WHY ?

Why do you run your bike out of balance ? I have never set up any bike, street or dirt, I owned out of balance. It the Dirt Bike world, that much of a difference is the difference between going over the Bars and stay level in the air, crashing and Landing smooth and fast.

I would think the same relates to the street...... well................ it always has for me anyway.

Are you referring to spring weight or sag setting?

[Redbird]

1.2 would be waaaaaaaaaay too stiff.

Agree completely. I had 1.0s on my XX when I was around 220lbs w/o gear. They were a little light, but close. 1.05s would have been perfect for me at that weight.

Stock is .89, so that is closer to what you'd need than 1.2s, which would be stupid stiff for your weight.

T, ?

Did you have to preload the springs ?

If yes, and if you can recall correctly, how big was your spacer ?

Yes, I had to preload the springs. It's been a very long time, but I think I ended up with somewhere close to an inch of preload- which is too much, which is why I commented that the springs were a little light for my application. No idea on spacer length, we're talking about 8-9 years ago and I can't remember what I had for breakfast this morning

[EVLXX]

As far as sag specs go, I run 44mm front and 34mm rear.

That's with an 1100 lb spring on the Penske and 1.0's in the front.

WHY ?

Why do you run your bike out of balance ? I have never set up any bike, street or dirt, I owned out of balance. It the Dirt Bike world, that much of a difference is the difference between going over the Bars and stay level in the air, crashing and Landing smooth and fast.

I would think the same relates to the street...... well................ it always has for me anyway.

Are you referring to spring weight or sag setting?

Well both actually.... they are relative to each other.

If your springs are not matched to give you the same lbs. of pressure / inch of compression, then as you compress the front and rear end over a given obstacle, weather it be in the road or on the trail, the stiffer spring would generate more compression for a given length of wheel travel, irregardless of the amount of Sag you have adjusted to. Then once you have the correct match up of springs for the application, you set your pre-load, or sag, and again "I" always make them match. In this way, my bike is always even and predictable when it hits an obstacle. If the front drops 2" due in part to the dip in the road, the back end drops 2" as well, so as I go through the dip, especially mid corner, the bike stays predicable, and hence I can due a better job of controlling the outcome.

1.2 would be waaaaaaaaaay too stiff.

Agree completely. I had 1.0s on my XX when I was around 220lbs w/o gear. They were a little light, but close. 1.05s would have been perfect for me at that weight.

Stock is .89, so that is closer to what you'd need than 1.2s, which would be stupid stiff for your weight.

T, ?

Did you have to preload the springs ?

If yes, and if you can recall correctly, how big was your spacer ?

Yes, I had to preload the springs. It's been a very long time, but I think I ended up with somewhere close to an inch of preload- which is too much, which is why I commented that the springs were a little light for my application. No idea on spacer length, we're talking about 8-9 years ago and I can't remember what I had for breakfast this morning

No worries, I was just curious. I finally order a set of springs for my Bird last week, and I'm hoping that the RaceTech spring weight combo works out correctly, because I didn't take the time to measure the Birds ratios first, and I assumed that the RT calculator is correct....

Call it lazy and trusting. (which I hope doesn't mean lazy and stupid)

Although, lazy had to leave for a while, when I went looking for a 18kg rear spring that would work on the stock shock, that was not easy.

In any event I'll find out when I get the springs installed if they are correct or not.

[Redbird]

If your springs are not matched to give you the same lbs. of pressure / inch of compression, then as you compress the front and rear end over a given obstacle, weather it be in the road or on the trail, the stiffer spring would generate more compression for a given length of wheel travel, irregardless of the amount of Sag you have adjusted to. Then once you have the correct match up of springs for the application, you set your pre-load, or sag, and again "I" always make them match. In this way, my bike is always even and predictable when it hits an obstacle. If the front drops 2" due in part to the dip in the road, the back end drops 2" as well, so as I go through the dip, especially mid corner, the bike stays predicable, and hence I can due a better job of controlling the outcome.

It's nowhere near that simple. Only way it could be is if you coasted everywhere you went and never used the brakes.

On the SV I run 35mm up front and 25mm out back, works quite well.

[HANKSXXX]

As far as sag specs go, I run 44mm front and 34mm rear.

That's with an 1100 lb spring on the Penske and 1.0's in the front.

WHY ?

Why do you run your bike out of balance ? I have never set up any bike, street or dirt, I owned out of balance. It the Dirt Bike world, that much of a difference is the difference between going over the Bars and stay level in the air, crashing and Landing smooth and fast.

I would think the same relates to the street...... well................ it always has for me anyway.

Are you referring to spring weight or sag setting?

Well both actually.... they are relative to each other.

If your springs are not matched to give you the same lbs. of pressure / inch of compression, then as you compress the front and rear end over a given obstacle, weather it be in the road or on the trail, the stiffer spring would generate more compression for a given length of wheel travel, irregardless of the amount of Sag you have adjusted to. Then once you have the correct match up of springs for the application, you set your pre-load, or sag, and again "I" always make them match. In this way, my bike is always even and predictable when it hits an obstacle. If the front drops 2" due in part to the dip in the road, the back end drops 2" as well, so as I go through the dip, especially mid corner, the bike stays predicable, and hence I can due a better job of controlling the outcome.

1.2 would be waaaaaaaaaay too stiff.

Agree completely. I had 1.0s on my XX when I was around 220lbs w/o gear. They were a little light, but close. 1.05s would have been perfect for me at that weight.

Stock is .89, so that is closer to what you'd need than 1.2s, which would be stupid stiff for your weight.

T, ?

Did you have to preload the springs ?

If yes, and if you can recall correctly, how big was your spacer ?

Yes, I had to preload the springs. It's been a very long time, but I think I ended up with somewhere close to an inch of preload- which is too much, which is why I commented that the springs were a little light for my application. No idea on spacer length, we're talking about 8-9 years ago and I can't remember what I had for breakfast this morning

No worries, I was just curious. I finally order a set of springs for my Bird last week, and I'm hoping that the RaceTech spring weight combo works out correctly, because I didn't take the time to measure the Birds ratios first, and I assumed that the RT calculator is correct....

Call it lazy and trusting. (which I hope doesn't mean lazy and stupid)

Although, lazy had to leave for a while, when I went looking for a 18kg rear spring that would work on the stock shock, that was not easy.

In any event I'll find out when I get the springs installed if they are correct or not.

First things first...

Why do you think the spring rates are mismatched?

[EVLXX]

It's nowhere near that simple. Only way it could be is if you coasted everywhere you went and never used the brakes.

On the SV I run 35mm up front and 25mm out back, works quite well.

True, and I'll back up a bit too ( too step back or rewind oneself). There are a host of other things that go into figuring out the loads on a suspension system, so without knowing all the other details, I shouldn't give broad suggestion or make accusations about another person setup. To further confound the matter I would also have to take in your style of riding, as a variable.

First things first...

Why do you think the spring rates are mismatched?

Same goes to you. You posted that you did/had a 1100 lbs rear and 1.0's up front. ( That's equal to a 19.4kg/mm on the Rear )

On both counts above, I have to assumed, (that might be the biggest problem right there) that the information given from a third party, that being RaceTech, is correct. I don't know if it is.

Then I have my Knowledge, and my opinions to throw in there, and everything can really get convoluted then.

....

So, without further ado.... there's a lot of great information on the subject here... http://www.webbikeworld.com/motorcycle-shocks-suspension/

[HANKSXXX]

As far as rear spring rate goes, that was Penske's suggestion.

Equally important to spring choice is compression and rebound dampening.

These things, along with oil viscosity, give quite a lot of things to screw up.

I tried a couple of different valves in the front with various combo's of shims.

I decided to use the Penske SuperSport valves.

I also tried .90, .95, 1.0, and 1.1 springs.

I liked the 1.0's as the best compromise for road conditions and riding style.

I run my fork oil, a 5 weight from Spectro, at a rather high 120mms. This was to help prevent bottoming out the fork.

While the pro's routinely set things up by feel, it took a trip through Cogent Dynamics shock dyno to get final compression/rebound valving balanced. I also had Rick go through the Penske and noticed an immediate improvement.

As far as sag goes, there are no set rules..only suggestions.

I lowered the rear of the bike so I could touch the ground flatfooted.

I had to lower the front to get back the responsive handling..

I also had to internally shorten travel in the front for the fender to clear the intercooler.

Once I had the ride quality I wanted and the handling I wanted, I recorded my sag..

That's where the #'s came from.

BTW, Rick said that Honda, along with other manufacturers, routinely run front sag in the 40mm-50mm range and rear in the 30-35mm range.

The bottom line is what works and after quite a lot of trial and error, I have a setup on this bike that does just that.

[EVLXX]

Thanks Hank for the fill in, that's what I was looking for.

T, notice the last paragraph of quoted article.... (helps me to understand more about your style)

..

Speaking of Sag.... I probably read this article when it was printed in 95... But then again I know I've been setting up my own suspension since 91. So.... somewhere I learned what I think I know, and it goes something like this....

Suspension and Springs - Sag

What's all this ruckus about suspension these days? It seems everyone is clued in that suspension setup can be a key to riding fast and safely, but how do you do it? No matter what shock or fork you have, they all require proper adjustment to work to their maximum potential. Suspension tuning isn't rocket science, and if you follow step-by-step procedures you can make remarkable improvements in your bike's handling characteristics.

The first step to setting up any bike is to set the spring sag and determine if you have the correct-rate springs. Spring sag is the amount the springs compress between fully topped out and fully loaded with the rider on board in riding position. It is also referred to as static ride height or static sag. My company, Race Tech, 951.279.6655 has an advanced method of checking spring sag that I'll describe.

If you've ever measured sag before, you may have noticed that if you check it three or four times, you can get three or four times, you can get three or four different numbers without changed anything. We'll tell you why this occurs and how to handle it.

REAR END

Step 1: Extend the suspension completely by getting the wheel off the ground. It helps to have a few friends around. On bikes with sidestands the bike can usually be carefully rocked up on the stand to unload the suspension. Most race stands will not work because the suspension will still be loaded by resting on the swingarm rather than the wheel. Measure the distance from the axle vertically to some point on the chassis (metric figures are easiest and more precise; Figure 1). Mark this reference point because you'll need to refer to it again. This measurement is L1. If the measurement is not exactly vertical the sag numbers will be inaccurate (too low).

Step 2: Take the bike off the stand and put the rider on board in riding position. Have a third person balance the bike from the front. If accuracy is important to you, you must take friction of the linkage into account. This is where our procedure is different: We take two additional measurements. First, push down on the rear end about 25mm (1") and let it extend very slowly.

Where it stops, measure the distance between the axle and the mark on chassis again. If there were no drag in the linkage the bike would come up a little further. It's important that you do not bounce! This measurement is L2.

Step 3: Have your assistant lift up on the rear of the bike about 25mm and let it down very slowly. Where it stops, measure it. If there were no drag it would drop a little further. Remember, don't bounce! This measurement it L3.

Step 4: The spring sag is in the middle of these two measurements. In fact, if there were no drag in the linkage, L2 and L3 would be the same. To get the actual sag figure you find the midpoint by averaging the two numbers and subtracting them from the fully extended measurement L1: static spring sag = L1 -[(L2 + L3) / 2].

Step 5: Adjust the preload with whatever method applies to your bike. Spring collars are common, and some benefit from the use of special tools. In a pinch you can use a blunt chisel to unlock the collars and turn the main adjusting collar. If you have too much sag you need more preload; if you have too little sag you need less preload. For road race bikes, rear sag is typically 25 to 30mm. Street riders usually use 30 to 35mm. Bikes set up for the track are compromise when ridden on the street. The firmer settings commonly used on the tract are generally not recommended (or desirable) for road work.

You might notice the Sag Master measuring tool (available from Race Tech) in the pictures. It's a special tool made to assist you in measuring sag by allowing you to read sag directly without subtracting. It can also be used as a standard tape measure.

Measuring front-end sag is very similar to the rear. However, it' much more critical to take seal drag into account on the front end because it is more pronounced.

FRONT END

Step 1: Extend the fork completely and measure from the wiper (the dust seal atop the slider) to the bottom of the triple clamp (or lower fork casting on inverted forks; Figure 2). This measurement is L1.

Step 2: Take the bike off the sidestand, and put the rider on board in riding position. Get and assistant to balance the bike from the rear, then push down on the front end and let it extend very slowly.

Picture

Where it stops, measure the distance between the wiper and the bottom of the triple clamp again. Do not bounce. This measurement is L2.

Step 3: Lift up on the front end and let it drop very slowly. Where it stops, measure again. Don't bounce. This measurement is L3. Once again, L2 and L3 are different due to stiction or drag in the seals and bushings, which is particularly high for telescopic front ends.

Step 4: Just as with the front, halfway between L2 and L3 is where the sag would be with no drag or stiction. Therefore L2 and L3 must be averaged and subtracted from L1 to calculate true spring sag: static spring sag = L1 - [l2 + l3) / 2].

Step 5: To adjust sag use the preload adjusters, if available, or vary the length of the preload spaces inside the fork.

Street bikes run between 25 and 33 percent of their total travel, which equates to 30 to 35mm. Roadrace bikes usually run between 25 and 30mm.

This method of checking sag and taking stiction into account also allows you to check the drag of the linkage and seals. It follows that the greater the difference between the measurements (pushing down and pulling up), the worse the stiction. A good linkage (rear sag) has less than 3mm (0.12") difference, and a bad one has more than 10mm (0.39"). Good forks have less than 15mm difference, and we've seen forks with more than 50mm. (Gee, I wonder why they're harsh?)

It's important to stress that there is no magic number. If you like the feel of the bike with less or more sag than these guidelines, great. Your personal sag and front-to-rear sag bias will depend on chassis geometry, track or road conditions, tire selection and rider weight and riding preference.

Using different sag front and rear will have huge effect on steering characteristics. More sag on the front or less sag on the rear will make the bike turn more slowly. Increasing sag will also decrease bottoming resistance, though spring rate has a bigger effect than sag. Racers often use less sag to keep the bike clearance, and since roadraces work greater than we see on the street, they require a stiffer setup. Of course, setting spring sag is only first step of dialing in your suspension, so stay tuned for future articles on spring rates and damping.

-Paul Thede

Magazine: Sport Rider

Issue : August 1995

[Redbird]

Eric, that's pretty much just instructions on how to set sag with very little other info. Not sure I see the point, other than he recommends the same sag front and rear.

More sag on the front or less sag on the rear will make the bike turn more slowly.

That seems totally backwards to me. Since when does lowering the front or raising the rear slow steering?

Anyway, an "imbalance" in front to rear sag is pretty common. Nothing wrong with setting it the same front and back, but don't marry yourself to the concept, it's simply not that cut and dry. Call it a good starting point.