Adjusting the FJR's suspension.......

[yamafitter]

Well the terms as I was taught them:

Free Sag: Just the bike

Static Sag: Bike and rider

Dynamic Sag: Amount of sag when bike is moving and leaned over in a corner. (Obviously not measurable)

Guess that's not the norm?

SkooterG has it right (did I actually just type that

)

I have to disagree with FredW that free sag doesn't mean anything. The reason that free sag is somewhat important is that this gives you an indication that the spring rate is correct for you as per the bike design. The designers work on getting the ride height that gives them the geometry that they want. Obviously under braking and with the front end under compression the geometry changes but these factors are all taken into consideration in the design phase.

When the spring rate is not correct the dynamic loads placed on the suspension are no longer within the design range of the compression and rebound adjustments to function as designed. This is why it is important to determine that the spring rate is correct as one of the first steps in suspension setup.

What is important to understand is that these are baseline readings and FredW is correct in stating that springs rates can be somewhat subjective but I would add only within a small range. If the spring rate is too far out there can be serious detrimental effects on the bikes handling.

If one has the Static Sag (as defined by SkooterG) set correctly and the Free Sag (Sag measurement with no rider) is within tolerance than the spring rate is correct for the load (Load being defined as you and all your stuff).

With this correct it is then time to start dialling in the compression and rebound adjustments for your riding style.

I base the above opinion based on over 40 years of bashing through the woods on dirt bikes where a properly working suspension makes the difference between riding through the obstacles vs crashing into them.

 

[LAF]

I can only add that at 0 miles I put a Penskey and 1.1.kg springs in and could not be happier in ride.

I went through Traxion and everything was set to my weight. Lee does know his FJR's.

The air space is way different as in way more, way less oil then stock. I am out to 3 rings, 11 clicks on the adjusters and 8 on the front forks.

I am very pleased with it. The rear is a dream, with weight for the road I turned up the bottom of the shock 3 clicks and the external adjuster about two flats, it road and handled the weight of my luggage which I guess at 125-150 pounds with no issues. So much so that when I had no load on I did not change it for our day trips and it road and handled perfect.

All of this stuff is fascinating to me and I keep re reading this to try and grasp this whole suspension thing.

 

[RadioHowie]

Okay, now nothing makes sense. Nothing at all.

Check THIS out...it totally contradicts what yamafitter and SkooterG define as STATIC and DYNAMIC sag, and it's from Wilbers, ferchrissakes!

Everywhere I look, it's different. Free sag, static sag, rider sag, dynamic sag, bike sag.....NOBODY agrees on what "sag" is or how to define it.

I'm leaving my suspension alone and savin' some money!!!

(stomps off crying like a girl)

 

[Bustanut joker]

Okay, now nothing makes sense. Nothing at all.

Everywhere I look, it's different. Free sag, static sag, rider sag, dynamic sag, bike sag.....NOBODY agrees on what "sag" is or how to define it.

(stomps off crying like a girl)

I know exactly where yer comin' from....These didn't help me but maybe you?

 

[beemerdons]

Okay, now nothing makes sense. Nothing at all.

Everywhere I look, it's different. Free sag, static sag, rider sag, dynamic sag, bike sag.....NOBODY agrees on what "sag" is or how to define it.

(stomps off crying like a girl)

I know exactly where yer comin' from....These didn't help me but maybe you?

Hey that's Brenda and I have an upcoming date with her, she's the gal I met on the "Hot Grandmothers" website that RadioHowie referred Papa Chuy to!

 

[Fontanaman]

I can only add that at 0 miles I put a Penskey and 1.1.kg springs in and could not be happier in ride.

I went through Traxion and everything was set to my weight. Lee does know his FJR's.

The air space is way different as in way more, way less oil then stock. I am out to 3 rings, 11 clicks on the adjusters and 8 on the front forks.

I am very pleased with it. The rear is a dream, with weight for the road I turned up the bottom of the shock 3 clicks and the external adjuster about two flats, it road and handled the weight of my luggage which I guess at 125-150 pounds with no issues. So much so that when I had no load on I did not change it for our day trips and it road and handled perfect.

All of this stuff is fascinating to me and I keep re reading this to try and grasp this whole suspension thing.

+1 The stock FJR suspension is woefully under-sprung. For 3 years I was a happy camper with the stock suspension - or so i thought. Early this year I road a EscapeFJRist's bike with GP Suspension and a Penske shock. What a huge difference. George says it is like putting the FJR on rails. He is right.

GP Suspension was bought by KFG Racing in Auburn WA so I went there to get my suspension upgraded. It cost a bit, but is worth every darn penny. It transforms the bike.

Since I don't know jack about the suspension I had all the work done by KFG Racing and happy I did. They listened to me and set it up to work for me.

 

[scubatech]

Okay, now nothing makes sense. Nothing at all.

Everywhere I look, it's different. Free sag, static sag, rider sag, dynamic sag, bike sag.....NOBODY agrees on what "sag" is or how to define it.

(stomps off crying like a girl)

I know exactly where yer comin' from....These didn't help me but maybe you?

Now those are great & funny as hell!!!!!

 

[RadioHowie]

WAYTAGO, SCUBA TECH!!!

Did we REALLY need to see those pictures again?

 

[Bustanut joker]

WAYTAGO, SCUBA TECH!!!

Did we REALLY need to see those pictures again?

:rofl: :yahoo:

 

[Fred W]

Okay, now nothing makes sense. Nothing at all.

Check THIS out...it totally contradicts what yamafitter and SkooterG define as STATIC and DYNAMIC sag, and it's from Wilbers, ferchrissakes!

Everywhere I look, it's different. Free sag, static sag, rider sag, dynamic sag, bike sag.....NOBODY agrees on what "sag" is or how to define it.

I'm leaving my suspension alone and savin' some money!!!

(stomps off crying like a girl)

Actually, those are the same definitions that I was using. But it doesn't really matter what we call them, that is just a matter of semantics. The important thing to know is that you want to set your sag with the bike fully loaded, whatever you call that. That is the primary sag adjustment. If you can't get that height set reasonably close to 1/3 of the total suspension stroke then you need to change out the spring. The unloaded bike's sag is of very little importance.

The only time checking the unloaded sag would be of significance is if you were using a progressive spring, in which case there can be variation in the proportion between loaded and unloaded sag due to the amount of preload applied.

But really, when will the bike ever ride down the road unloaded? :huh:

This has been a pretty good discussion so far. Let's continue it and discuss the 2 basic types of damping adjustments available.

First let's define that damping is a resistance of the suspension to change its length over a period of time. Regardless of what kind of damping we are talking about (compression or rebound, fast or slow), the suspension will eventually reach an equilibrium of the weight being supported vs. the spring's tension.

We have compression damping, which is a one-way damping to compress the fork or shock, and there is rebound which is the damping of the fork or shock to extend.

The end goal of suspension damping, whether it is for racing or road riding, is exactly the same: To keep the chassis of the vehicle as stationary as possible while allowing the wheel to follow the undulations of the roadway as much as possible, to maintain the maximum traction for braking, steering and acceleration. A wheel that is airborne is no good at any of those things. And a chassis that is being hurled about by the road surface is not easy nor comfortable to pilot.

So who has a good description of the adjustments?

 

[RadioHowie]

Actually, those are the same definitions that I was using. But it doesn't really matter what we call them, that is just a matter of semantics. The important thing to know is that you want to set your sag with the bike fully loaded, whatever you call that. That is the primary sag adjustment. If you can't get that height set reasonably close to 1/3 of the total suspension stroke then you need to change out the spring. The unloaded bike's sag is of very little importance.

FINALLY!! Something that makes perfect sense! Thanks a BUNCH, bud! :thumbsupsmileyanim:

So, if I want to do it "right", check and set the "unloaded" sag, then, climb aboard, measure the "loaded" sag, and if it's not right, go spring shopping!

For a Gen I with 75k miles, and a 270lb rider, that would more than likely mean higher rate springs, correct??

 

[SkooterG]

Actually, those are the same definitions that I was using. But it doesn't really matter what we call them, that is just a matter of semantics. The important thing to know is that you want to set your sag with the bike fully loaded, whatever you call that. That is the primary sag adjustment. If you can't get that height set reasonably close to 1/3 of the total suspension stroke then you need to change out the spring. The unloaded bike's sag is of very little importance.

FINALLY!! Something that makes perfect sense! Thanks a BUNCH, bud! :thumbsupsmileyanim:

So, if I want to do it "right", check and set the "unloaded" sag, then, climb aboard, measure the "loaded" sag, and if it's not right, go spring shopping!

For a Gen I with 75k miles, and a 270lb rider, that would more than likely mean higher rate springs, correct??

Yes!

I am only 180 lbs and my I have 1.1kg springs in my 04. Those are TWO sizes (heavier rate) up from the stock's .85kg springs. Not sure what is on my custom shock, but it works. My 04 handles AWESOME. Much better than my 09. Of course as has been said before, it's not all about spring rate. I have better valving and adjustability both front and rear and that plays a HUGE part too. Truth be told, I have NEVER measured the SAG on my 04. Just played with compression and rebound damping.

 

[Fred W]

It was a little difficult, but I was able to put BMW grips on with OEM heated grips. Are the new ones different?

The hardest parts is giving up the beautifully routed wires thought the OEM grips but seems you can change them out if you want to.

So I'll ask again, why not use grip puppy sleeves over the OEM grips? They work well on BMW heated grips and should also on an FJR.

The heating elements appear to be directly ingrained in the grip material, so for me, I am reasonably sure these grips will remain on the bike.

I will likely try out a set grip puppies at some point, but for now, my #1 item of pursuit is dealing with the mirror recesses.

And I will agree here with Greg. Sag wants to be established first, because it influences your damping adjustments later. But if you just stick with whatever spring rate you have and dial it in from there, you can get a good suspension system tune state.

The one spring rate variable that has (up to now) been undisclosed is that, the harder and faster you ride, the more likely you are to exceed the limits of your suspension. When you ride faster, impact with a particular bump will be harder, cornering forces will be more severe, and unweighting that occurs on the back side of bumps will also be more intense. Why do you think they say "I was really flying?". So for those that really have the need for extreme speed you will necessarily want more spring rate, more rebound damping to counteract the beefy spring, and less compression damping in your system, in order to keep your wheels on the road and your butt in the seat.

 

[AlleyCat]

I adjusted sag first (was too much sag with stock settings for my 200 lbs - nose would dive big time under braking), then rebound and I finished with compression. I found that rebound settings were too harsh at first and it felt like the bike was falling into slow speed turns. Under aggressive riding I could feel the bike wanting to stand up in bumpy turns (bike was bouncing back too fast - felt like wallowing to some degree). I started making 1 or 2 click adjustments and with time I finally have rebound at a setting were the bike feels good. I still feel like I may want to tweak my compression damping to see how the feel of the bike changes. The initial mistake was that the number of clicks I made on the rebound and compression damping settings. Seeing that the left and right sides have different number of clicks, I compensated the number of clicks to keep a 'ratio' which does not seem to work. For example, compression damping : I have a range of 28 clicks on the left and 41 clicks on the right. Instead of having 10 clicks each side, I would set the left at 10 clicks and the right at 15. I never got good results. Afterwards, I simply put each side at the same number of clicks. Same with rebound settings (total clicks differ from one side to the other).

Setting your suspension is not a simple exercise to be done is one day. Be prepared to spend some time playing with your settings and making notes. I still feel like the bike is just off the right settings for me. I still have to play with the rear settings. I have the lever on hard seeing that I had way too much sag on the rear. Now to tinker with the rebound damping to see if I can improve overall feel of the bike. I find it difficult to accurately describe how the setting change the feel of the bike. What feels like wallowing to me can be something different to you. Take it slow, patience is the key.

 

[Fred W]

That sounds like you've adjusted your damping in much the same way that I do: Iteratively, by trial and error.

My "technique" if you can call it that, is to start with minimum damping settings and incrementally increase it a couple of clicks CW at a time until "bad stuff" happens, then back it off a click or two.

The bad stuff for the compression damping is really easy to feel. That is the point where the shock can no longer follow the bump and the bike feels very harsh over bumps. For some reason I thought that setting the compression first was easier. It is definitely the easier of the two to feel.

The bad stuff for the rebound is the suspension starts to "pack up" and squat over a series of bumps, and that one is a lot harder for me to feel. I'd really like some help with a better way for setting rebound correctly.

As has already been stated, on the stock rear shock the "rebound" adjust actually affects both rebound and compression so you'd have to feel for both scenarios as you advance the clicker.

 

[MCRIDER007]

The bad stuff for the compression damping is really easy to feel. That is the point where the shock can no longer follow the bump and the bike feels very harsh over bumps. For some reason I thought that setting the compression first was easier. It is definitely the easier of the two to feel.

The rebound damping adjustment is a tapered needle that blocks oil flow to slow the rebound stroke....but the oil can flow in both directions past the needle so it is also a part of the low speed compression damping circuit.....so when you increase rebound damping (reduce oil flow) you are also increasing compression damping....but the change in oil flow past the rebound needle is less than the change in oil flow pass the compression adjusters on the bottom of the fork so the effect on compression damping is not as great. The bottom line is that you should adjust the rebound damping first. Some of the very high end racing forks use a one way valve in the rebound circuit to stop oil flow in both directions so that the rebound damping adjustment will not alter compression damping.

 

[AVGeek]

Suspension settings are the most "black arts" settings to me. Skooty, if you and Don want to do another suspension tech day, I have a large shop at my house available to work in...

 

[AlleyCat]

That sounds like you've adjusted your damping in much the same way that I do: Iteratively, by trial and error.

My "technique" if you can call it that, is to start with minimum damping settings and incrementally increase it a couple of clicks CW at a time until "bad stuff" happens, then back it off a click or two.

The bad stuff for the compression damping is really easy to feel. That is the point where the shock can no longer follow the bump and the bike feels very harsh over bumps. For some reason I thought that setting the compression first was easier. It is definitely the easier of the two to feel.

The bad stuff for the rebound is the suspension starts to "pack up" and squat over a series of bumps, and that one is a lot harder for me to feel. I'd really like some help with a better way for setting rebound correctly.

As has already been stated, on the stock rear shock the "rebound" adjust actually affects both rebound and compression so you'd have to feel for both scenarios as you advance the clicker.

When I was tweaking my rebound damping, I had another person hold the bike on one side without compromising the up and down movement of the bike. I would then push the bike down (hard) and release it to see how she came back up. At first, I could see that the bike was coming up and dropping again... played with the settings until the bike would come back up without having that 2nd bounce if you will. Also, if you have the bike come up too fast, then rebound damping is required (to slow it's return). It should take about a second for the bike to come back up. anything faster and you may need some adjustment. I also watch for the bike to move in one motion without the front or back being out of sync. The ends should flow together.

 

[Fred W]

Thanks boys. Great info.

I did not know that the rebound effects the compression, I will try doing it in that order and see if that makes it any easier.

I've also tried to use the "stationary" bounce adjust on the rebound. It gets it closer, I guess, but it all still seems an awful lot like the black magic that AV Geek refers to, to me too.

 

[AlleyCat]

Thanks boys. Great info.

I did not know that the rebound effects the compression, I will try doing it in that order and see if that makes it any easier.

I've also tried to use the "stationary" bounce adjust on the rebound. It gets it closer, I guess, but it all still seems an awful lot like the black magic that AV Geek refers to, to me too.

Nothing beats riding the bike and getting a real world feel for the settings. Like I mentioned earlier, I have my settings almost there, but something still seems a hair off. Anyone here compensate for the different number of clicks from the left and right sides or do you just set the same number each side ? Suspension settings are complex and require lots of fiddling around until that sweet spot is found....