[motomania]

Ahh, ok. I was under the impression "ride height" was the distance from frame to ground achieved by adjusting preload, "sag" was the amount of free play from the resting bike to the top of the shock stroke, and "length of suspension" was just the length of the shock eye to eye. But as I said I'm coming from quads so different nomenclature I guess!
You mentioned in a previous post stock springs are set for 150lb rider, I'm about 160 with gear. Should be fine for the average daily rider. What is the ideal sag people should be shooting for with a properly matched spring?

General rule for static sag is about 30% of your total wheel travel (TWT).

How do you figure this out (rear wheel):
1) Have a buddy hold the bike upright (not on the side stand) and pull up on the bike until there is no weight on the rear suspension.
2) Measure between the axle and a fixed point (FP) on the bike directly above the axle. Write this number down as it is your Fully Extended Suspension number (FE). Lets say in an example bike FE = 350 mm.
3) Fully geared up and ready to ride, the rider gets on the bike, in riding position.
4) First buddy holds the bike upright BY THE HANDLEBARS
5) Second buddy PUSHES DOWN the rear of the bike down a couple of inches and lets the bike SLOWLY come back up.
6) Second buddy measures between axle and FP and write this down as L1. Continuing our example above L1 = 300mm
7) Sometimes it is good to do 5-6 a couple of times so you get a consistent L1 number.
8) Second buddy PULLS UP the rear of the bike a couple of inches and lets the bike SLOWLY come back down.
9) Second buddy measures between axle and FP and write this down as L2. Continuing our example above L2 = 320mm
10) Sometimes it is good to do 8-9 a couple of times so you get a consistent L2 number.
11) Calculate current sag = FE - [(L1 + L2)/2] Continuing the example: 350mm - [(300mm + 320mm)/2] = 350mm - 310mm = 40mm. Current sag is 40mm

But what is the ideal sag for this bike?

Look at the owners manual and find out the total rear wheel travel (TWT). If the total rear wheel travel (TWT) is 110mm then you multiply 110mm X 30% = 33mm is your target static sag number.

Now, go back to the rear shock. Since you currently have 40mm sag that is too much sag so you need to add A LITTLE preload to the rear spring and then repeat steps 3-11 to determine your newly adjusted sag.

If you added too much preload, your newly adjusted sag will be less than 33 mm.

If you did not add enough preload, your newly adjusted sag is somewhere between 40mm and 33mm.

You may need to add or remove a little preload and repeat steps 3-11 until you get to 33 mm static sag.

I don't have the owner's manual for the XSR in front of me so the 110mm total travel and the target 33 mm static sag is just an example and not necessarily correct for the XSR.

As you can see, the sag is function of the rider and the bike. So what works for a 140 lb rider will not be the same as for a 180 lb rider or 230 lb rider (like me). Further, if you do not have the correct springs installed to handle the weight of the rider, you can never get to the correct sag numbers.

You should also follow the same basic process for the front but it is important that the bike is held upright by the REAR of the bike while measuring the front sag.

 

[Rocky_MTN_FZ09]

Please note that the XSR900 has the suspension of the FZ/MT-09 2016 model! It is not comparable to the models 2014/2015.

According to the following links, the fork springs for a 2016 XSR900 are the same as the 2015 FJ-09. The 2014 and 2016 FZ-09 have the same fork springs.

2016 XRS900: 2016 Yamaha XSR900G Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 2PP-23141-00-00 $40.82

2015 FJ-09: 2015 Yamaha FJ09 (FJ09FGY) Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 2PP-23141-00-00 $40.82

2014 FZ-09: 2014 Yamaha FZ09 (FZ09EGY) Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 1RC-23141-00-00 $42.48

2016 FZ-09: 2016 Yamaha FZ09 (FZ09GB) Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 1RC-23141-00-00 $42.48

 

[motomania]

According to the following links, the fork springs for a 2016 XSR900 are the same as the 2015 FJ-09. The 2014 and 2016 FZ-09 have the same fork springs.

2016 XRS900: 2016 Yamaha XSR900G Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 2PP-23141-00-00 $40.82

2015 FJ-09: 2015 Yamaha FJ09 (FJ09FGY) Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 2PP-23141-00-00 $40.82

2014 FZ-09: 2014 Yamaha FZ09 (FZ09EGY) Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 1RC-23141-00-00 $42.48

2016 FZ-09: 2016 Yamaha FZ09 (FZ09GB) Front Fork | YamahaPartsPitstop.com
13. .Spring, Front Fork P/N 1RC-23141-00-00 $42.48

What I had read from the suspension folks like Stoltec and Traxxion Dynamics was the suspension was the same in all 3 bikes across all model years or that at least any differences in valving that might be there were not significant.

Interesting that the same fork springs has a different price depending on the model...

Some misrepresentation going on there...

 

[-BB]

General rule for static sag is about 30% of your total wheel travel (TWT).

How do you figure this out (rear wheel):
1) Have a buddy hold the bike upright (not on the side stand) and pull up on the bike until there is no weight on the rear suspension.
2) Measure between the axle and a fixed point (FP) on the bike directly above the axle. Write this number down as it is your Fully Extended Suspension number (FE). Lets say in an example bike FE = 350 mm.
3) Fully geared up and ready to ride, the rider gets on the bike, in riding position.
4) First buddy holds the bike upright BY THE HANDLEBARS
5) Second buddy PUSHES DOWN the rear of the bike down a couple of inches and lets the bike SLOWLY come back up.
6) Second buddy measures between axle and FP and write this down as L1. Continuing our example above L1 = 300mm
7) Sometimes it is good to do 5-6 a couple of times so you get a consistent L1 number.
8) Second buddy PULLS UP the rear of the bike a couple of inches and lets the bike SLOWLY come back down.
9) Second buddy measures between axle and FP and write this down as L2. Continuing our example above L2 = 320mm
10) Sometimes it is good to do 8-9 a couple of times so you get a consistent L2 number.
11) Calculate current sag = FE - [(L1 + L2)/2] Continuing the example: 350mm - [(300mm + 320mm)/2] = 350mm - 310mm = 40mm. Current sag is 40mm

But what is the ideal sag for this bike?

Look at the owners manual and find out the total rear wheel travel (TWT). If the total rear wheel travel (TWT) is 110mm then you multiply 110mm X 30% = 33mm is your target static sag number.

Now, go back to the rear shock. Since you currently have 40mm sag that is too much sag so you need to add A LITTLE preload to the rear spring and then repeat steps 3-11 to determine your newly adjusted sag.

If you added too much preload, your newly adjusted sag will be less than 33 mm.

If you did not add enough preload, your newly adjusted sag is somewhere between 40mm and 33mm.

You may need to add or remove a little preload and repeat steps 3-11 until you get to 33 mm static sag.

I don't have the owner's manual for the XSR in front of me so the 110mm total travel and the target 33 mm static sag is just an example and not necessarily correct for the XSR.

As you can see, the sag is function of the rider and the bike. So what works for a 140 lb rider will not be the same as for a 180 lb rider or 230 lb rider (like me). Further, if you do not have the correct springs installed to handle the weight of the rider, you can never get to the correct sag numbers.

You should also follow the same basic process for the front but it is important that the bike is held upright by the REAR of the bike while measuring the front sag.

Awesome info. Thanks for this!

 

[Keef]

I had a 2016 mt09 for a day when I gave the xsr in for the 1000k service.

To be honest, I didn't notice a huge diff between the two suspensions and I had mine on stock at the time. Maybe different to earlier models, though?

Front sag is ~30, rear ~40 for me.

Good explanation of the physics, btw. Always helps to get a bit if theory in your head...

Sent from my HTC_0P6B6 using Tapatalk

That means the back end is lower than the front, like a fat kid sitting on a see saw by himself.
add some rear preload to the rearso you have less on the back.
More preload on the rear will shift the weight to the front, so you will have more weight on the front the front wheel, and better steering.

For all the XSR guys, the MT had such badly damped suspension that the long term members have been through these questions before, so we know what we are talking about. If the XSR has the same springs as the MT has always had, the damping may have changed a bit, but could still do with some tweaking.

 

[madboy48]

That means the back end is lower than the front, like a fat kid sitting on a see saw by himself.
add some rear preload to the rearso you have less on the back.
More preload on the rear will shift the weight to the front, so you will have more weight on the front the front wheel, and better steering.

For all the XSR guys, the MT had such badly damped suspension that the long term members have been through these questions before, so we know what we are talking about. If the XSR has the same springs as the MT has always had, the damping may have changed a bit, but could still do with some tweaking.

Sounds like a plan. I'll make the changes this weekend. The access to the spring is diabolical - so difficult to make a simple change.

fair enough regarding the experience. part of the fun is to decide where to spend the pocket money given so many options (suspension, exhaust, bling, etc)

 

[Rocky_MTN_FZ09]

It's worth trying to set the sag and see how the stock suspension works, what do you have to loose??? lol

 

[motomania]

It's worth trying to set the sag and see how the stock suspension works, what do you have to loose??? lol

If you weigh a lot more than 160, like 200, and screw in so much preload to try to compensate for 40lb too soft springs, the ride quality will be pretty harsh and the traction fairly reduced as a result.

Too much preload is a bad thing.

You are correct, if you don't have the cash you can try to add some preliad but you will never get it quite right.

 

[olivernz]

"Despite having the same length forks, the XSR900 has vastly improved damping as well as a revised seating position (you sit taller and further back on the new seat and subframe) that make it handle far more like a traditional naked bike. There is no pitching in bends and you can brake hard into corners without the front pinging back and upsetting the bike's balance. Is it as good as a Street Triple? It's certainly not far off and that's impressive considering the Triumph is basically a stripped down sports bike."

RE: Yamaha XSR900: PH2 - Page 1 - Biker Banter - PistonHeads

Not that I can argue as I only rode an FJ-09 so far and that was pretty spongy but I'm sure it was set up badly.

 

[emjay]

General rule for static sag is about 30% of your total wheel travel (TWT).

How do you figure this out (rear wheel):
1) Have a buddy hold the bike upright (not on the side stand) and pull up on the bike until there is no weight on the rear suspension.
2) Measure between the axle and a fixed point (FP) on the bike directly above the axle. Write this number down as it is your Fully Extended Suspension number (FE). Lets say in an example bike FE = 350 mm.
3) Fully geared up and ready to ride, the rider gets on the bike, in riding position.
4) First buddy holds the bike upright BY THE HANDLEBARS
5) Second buddy PUSHES DOWN the rear of the bike down a couple of inches and lets the bike SLOWLY come back up.
6) Second buddy measures between axle and FP and write this down as L1. Continuing our example above L1 = 300mm
7) Sometimes it is good to do 5-6 a couple of times so you get a consistent L1 number.
8) Second buddy PULLS UP the rear of the bike a couple of inches and lets the bike SLOWLY come back down.
9) Second buddy measures between axle and FP and write this down as L2. Continuing our example above L2 = 320mm
10) Sometimes it is good to do 8-9 a couple of times so you get a consistent L2 number.
11) Calculate current sag = FE - [(L1 + L2)/2] Continuing the example: 350mm - [(300mm + 320mm)/2] = 350mm - 310mm = 40mm. Current sag is 40mm

But what is the ideal sag for this bike?

Look at the owners manual and find out the total rear wheel travel (TWT). If the total rear wheel travel (TWT) is 110mm then you multiply 110mm X 30% = 33mm is your target static sag number.

Now, go back to the rear shock. Since you currently have 40mm sag that is too much sag so you need to add A LITTLE preload to the rear spring and then repeat steps 3-11 to determine your newly adjusted sag.

If you added too much preload, your newly adjusted sag will be less than 33 mm.

If you did not add enough preload, your newly adjusted sag is somewhere between 40mm and 33mm.

You may need to add or remove a little preload and repeat steps 3-11 until you get to 33 mm static sag.

I don't have the owner's manual for the XSR in front of me so the 110mm total travel and the target 33 mm static sag is just an example and not necessarily correct for the XSR.

As you can see, the sag is function of the rider and the bike. So what works for a 140 lb rider will not be the same as for a 180 lb rider or 230 lb rider (like me). Further, if you do not have the correct springs installed to handle the weight of the rider, you can never get to the correct sag numbers.

You should also follow the same basic process for the front but it is important that the bike is held upright by the REAR of the bike while measuring the front sag.

There's a few postings out there regarding suspension and settings, but I wanted to chime in here, since Motomania provided some good information on calculating sag. Note - I've hated the stock rear suspension settings since I bought the bike, as the rear felt way too stiff with the stock settings, giving me a nice kick in the ass going over some of the smallest highway bumps. I finally got around to messing with the suspension settings, and wanted to provide this input...

Just to note, I'm 6' 190lbs, and don't have any immediate plans to track this bike. The owners manual defines TWT for the rear at 130mm, and based off a general rule, you're looking at around 39mm target sag for the rear. Although, it's nice that Yamaha provided a spanner wrench in the toolkit under the seat, it's a huge PITA to turn that thing due to limited working space, so I had my dealer do it recently when they were putting in a new master link on my chain. (somehow I lost an O ring on a link - wtf). So while I was there, I explained to them how stiff the rear felt, and asked if he could lighten the preload for me. He ended up backing it off all the way to the softest setting (1). I never calculated the original sag, but now I'm looking at around 38mm with the preload adjusted to the softest.

Currently, it's much better than it was stock, and seems to handle whatever I'm throwing at it sufficiently. Nowhere near the performance of some of my super sport bikes in the past, but I guess that's to be expected. I wish there were more adjustment settings for the stock suspension (like the 2ring setup on Ohlins springs), but it is what it is. I actually think this bike has more adjustment options than a lot of others in its class. (Ex. I don't even think you can adjust a Monster 821's front suspension at all).

I'm still dialing in the rebound settings for the front and rear, but they both seem to be playing nicely together, rebounding at approximately the same rate. In the front, I'm currently running 5 clicks. In the rear, I'm running 3/4 turns. As for my front suspension, I'm currently running the stock preload (5 lines), but may add a little as well.

It'll be a work in progress over the next few weeks. Again, the suspension isn't great, but overall, it's doing a much better job now. I may end up investing in a new suspension down the road, but for now, this will do.

 

[XSR-900]

After riding only 360 miles so far on my new XSR, the suspension in the stock settings is definitely "stiff" on rough back roads. If you hit some really rough stuff, the handle bars really get violent and you get kicked in the ass by the seat. Even after hitting some really rough stuff, my front forks are only traveling 3.5~4 inches from the no sag position. I'd say my forks only have about 1/2~3/4" sag max. I'm about 195 with riding gear.

After reading this thread, it seems my observations are the same as some others posting here. I think Yamaha probably made the suspension a bit too stiff if this is what I see with the factory settings which are all about in the middle of their range. Setting everything to max pre-load and max dampening would probably make it feel like it has no suspension.

 

[motomania]

If ypu only have 1/2-3/4" sag, then you have way too much preload and it will requirerelatively large bumps to make it move at all and thus cause a very harsh ride.

 

[XSR-900]

The "standard" setting for the front suspension spring pre-load is distance c = 16 mm. The softest setting is c = 19 mm. Seems the standard pre-load setting on the front springs is biased towards the soft side, but still seems pretty stiff for really rough roads at the standard setting. I understand the suspension is setup somewhat stiff on this bike for handling (which it does very well), so having a somewhat harsh ride on rough roads is part of the equation.

I just rechecked my front suspension factory pre-load setting. On the standard factory pre-load (c=16 mm), I get 38 mm (1.5 inches) of front fork sag when sitting on the bike - I'm ~180 lbs without gear. It might sag another mm or two with riding gear on. So it does look like I have the ~30% of travel sag with the factory setting on the front forks (1.57 with 2mm more sag/5.4" total travel = 29.2%).

Maybe the rebound damping is too high and causes the suspension to not rebound fast enough on really rough roads, thereby giving a harsh ride. I might reduce the damping some and see how that feels.

 

[motomania]

too little or too much rebound damping can cause a harsh ride.

 

[XSR-900]

too little or too much rebound damping can cause a harsh ride.

Hopefully it's too much rebound damping since that is the only one adjustable on the XSR.

 

[Nongbee]

I can't seem to get mine right. I can't really afford aftermarket now.
I weigh 62kg, maybe 65 with gear. I think the springs are just too stiff for me :-(

 

[motomania]

I can't seem to get mine right. I can't really afford aftermarket now.
I weigh 62kg, maybe 65 with gear. I think the springs are just too stiff for me :-(

You are at the bottom of the scale for what the stock suspension is set up for.

I suggest reducing the preload to minimum and checking the static sag. See if you can get static sag to about 35mm in the front.

Once you have the static sag set, then reduce the rebound damping to only 2-3 notches from minimum and see how that works.

Also know you need to adjust the rear shock as well.

If that does not help smooth the ride, you can also reduce the oil level in the forks by about 10-15 mm and that will soften things up a little as well.

 

[XSR-900]

I just looked at my rear suspension. The spring pre-load is set at position #4 which is the factory setting and right in the middle of the adjustment range. Position #1 is softest, and position #7 the hardest.

The rear suspension doesn't even move down at all from the bike's own weight when the suspension is pulled all the way up as the sag starting point. I need to figure out how I can measure the sag with me on it, probably have a helper measure from the floor while I sit on the bike. But just by looking at it while I put my weight on the seat it might only sag 1/2" or so. My front pre-load sag was just about right with the factory setting, but I'm betting the rear spring will have to be taken down a notch or two to soften up the pre-load a little bit.

Is the rear suspension also supposed to have ~30% of the full travel (5.1 inches) for the sag amount with rider weight? That would mean the rear sag should be around 1.5 inches also (39 mm).

 

[motomania]

Is the rear suspension also supposed to have ~30% of the full travel (5.1 inches) for the sag amount with rider weight? That would mean the rear sag should be around 1.5 inches also (39 mm).

Yes

And you need 2 helpers to measure sag. One helper supporting the bike. One helper doing the measuring.

 

[XSR-900]

I was able to accurately measure the rear suspension sag on my XSR today with the help of a friend. Used a steel tape measure and recorded the distance from the floor to the front tip of the rear turn signal, which is almost directly above the rear wheel axle. I was in my riding gear and weighed myself to be 196 lbs when sitting on the bike for the sag measurements. If you do this, be sure to have the bike as vertical as possible because any leaning of the bike will throw off the distance from the floor to whatever point on the bike you are using to measure the sag.

With the rear shock pre-load at the factory setting (position #4), the sag was ~1 inch.

With the rear shock pre-load at one notch softer (position #3), the sag was ~1-1/4 inches.

With the rear shock pre-load at two notches softer (position #2), the sag was ~1-1/2 inches. This setting for me is ~30% of the total rear suspension travel of 5.1 inches. (1.5/5.1)x100 = 29.4%.

So, in summary ... for a ~200 lbs rider (with gear on), each pre-load adjustment notch of the rear shock gives ~1/4" change in sag.

Now my rear suspension sag is matching the front sag at 30% of full travel. Took the bike for a ride and noticed the difference ... the front and rear suspension seems to feel better matched now. Taking the bike fast through some tight twisty roads confirms it still handles very well ... maybe even better if you hit some rough stuff in a corner.

I'm going to play with the rebound damping in the next few days also and see how that feels. I think the rebound damping setting from the factory might be a hair too high for rough roads, thereby not allowing the suspension to rebound fast enough for the next suspension compression when the bumps on the road are super close to each and you're going pretty fast.