ST1300 - Unstable when riding behind a semi truck?

[MidLife]

So you ARE including the shock being topped out in the discussion. Of course the spring gets shorter then.

This is not me including it. Am only trying to help with understanding preload based on jf's illustration.

Be it on the bench or extended on the bike, step 4 merely illustrates how preload is applied.

I only care about what happens under riding conditions, so only figures 2 and 5 matter in the discussion.

Except that 5 can only occur after you add preload as illustrated under 4.

Those are the only conditions that occur while the bike is in use.

Maybe statically in your garage. But Dynamically, when you get rolling, there are plenty of times where you are sitting on your bike with the shock fully extended under you.

Does damping alter between the two?

Again, you are going back to square one here. I thought your "Hooray" meant you finally understood the difference between damping adjustment and rebounding of the suspension. They are not the same.

So again.....Preload does not change damping settings....it only affects the bouncing characteristics of the suspension. Please do not mix the two.

So...

Does damping alter between the two?

No. Preload adjustment does NOT alter damping (except on some of the modern electronic controlled suspensions), but it does alter the bouncing response of the suspension, as demonstrated in the Dave Moss vid.

 

[MidLife]

It sounds like everyone should have been saying to remember to adjust damping when you adjust the "preload" instead of implying that it automatically will adjust itself as you do.

So...first you keep insisting that preload and damping are two complete separate systems with no link at all, one cannot possibly affect the other.....and now you claim you thought damping was automatically adjusted when playing with the preload......where is the logic!

And by the way, every tuning book or article suggests you first adjust preload, and then tune up damping accordingly.

 

[MidLife]

Actually - I like @MidLife's explanation of the 5 stages in my diagrams, better than my own. I may (with your permission) quote that in my original explanation. Two ways of describing the same thing are always a good idea.

Of course!

Adding pre load does not affect the damping. But adding more weight to the bike will.

Please....help with containing confusion on that.

Adding more weight does NOT affect damping. It affects the bouncing characteristics of the suspension. Actual damping setting can only be altered by changing the setting of the damping valve itself.

Am trying to get Mr Fine to see that.

As you say here below, more weight will require more damping....and so does more preload!

There is more weight and inertia to slow down than there was before, so something to stop it rebounding quickly and then bouncing again is needed - so it might feel as though it has affected the original setting. In fact it hasn't. Its just that it was perfectly ok for the previous weight, but now you have added more, you need a bit more damping to slow it down.

RIght, it doesn't affect damping. Just the need for more of it.

Adding pre load does not affect the damping...

Yes, nothing affects damping beside adjusting it. But preload clearly also affects rebound characteristics. See the Dave Moss vid for demonstration at 3:30 and 1:40 where he gets rid of front fork bouncing just by releasing some of the preload, with no damping adjustment.

You understand enough about suspensions to figure out why it is so if you'll wrap your head around it.

On a bike without rebound damping adjustment, it will be on the bouncy side with too much preload, and packing side with not enough of it.

 

[Larry Fine]

This is not me including it. Am only trying to help with understanding preload based on jf's illustration.

Be it on the bench or extended on the bike, step 4 merely illustrates how preload is applied.

Or when, i.e., while off the bike and on the center stand to make adjusting easier.

Except that 5 can only occur after you add preload as illustrated under 4.

If you could adjust it while riding, you wouldn't need #4.

I'm not bothering with what happens during the adjustment, because you're not riding.

I'm merely comparing riding with the spring adjuster in either of two positions.

Maybe statically in your garage. But Dynamically, when you get rolling, there are plenty of times where you are sitting on your bike with the shock fully extended under you.

You mean while flying after a bump, with no weight on the rear wheel? That would happen no matter what. There's nothing we can do about the road.

In a theoretical, all-other-things-being-equal discussion, there's no reason to bring up things that don't change, or have no variable effect the outcome.

Again, you are going back to square one here. I thought your "Hooray" meant you finally understood the difference between damping adjustment and rebounding of the suspension. They are not the same.

No, I was cheering because someone finally differentiated between damping characteristics changing with applied weight and damping values actually changing with spring adjustment.

So again.....Preload does not change damping settings....it only affects the bouncing characteristics of the suspension. Please do not mix the two.

That's the difference that was not explained before today; thus the "Hooray!"

No. Preload adjustment does NOT alter damping (except on some of the modern electronic controlled suspensions), but it does alter the bouncing response of the suspension, as demonstrated in the Dave Moss vid.

That makes perfect sense. The bike's damping needs change, not with preload changes, but with the reason for making the preload changes.

 

[Larry Fine]

So...first you keep insisting that preload and damping are two complete separate systems with no link at all, one cannot possibly affect the other.....and now you claim you thought damping was automatically adjusted when playing with the preload......where is the logic!

No, I was saying that the claims were saying that it did.

And by the way, every tuning book or article suggests you first adjust preload, and then tune up damping accordingly.

That makes perfect sense, and I never would have disagreed with it.

 

[Larry Fine]

Adding more weight does NOT affect damping. It affects the bouncing characteristics of the suspension. Actual damping setting can only be altered by changing the setting of the damping valve itself.

That's what I've believed from the beginning.

Am trying to get Mr Fine to see that.

Since it has been explained, he does.

As you say here below, more weight will require more damping....and so does more preload!

RIght, it doesn't affect damping. Just the need for more of it.

Exactamundo!

Yes, nothing affects damping beside adjusting it. But preload clearly also affects rebound characteristics. See the Dave Moss vid for demonstration at 3:30 and 1:40 where he gets rid of front fork bouncing just by releasing some of the preload, with no damping adjustment.

You understand enough about suspensions to figure out why it is so if you'll wrap your head around it.

On a bike without rebound damping adjustment, it will be on the bouncy side with too much preload, and packing side with not enough of it.

I do get all of this. I still thing steering effort is more sensitive to ride height, though, and will continue to guide my rear suspension height.

It would be cool to have appropriate damping settings, but I'd be concerned with making things worse,

 

[MidLife]

So...first you keep insisting that preload and damping are two complete separate systems with no link at all, one cannot possibly affect the other.....and now you claim you thought damping was automatically adjusted when playing with the preload......where is the logic!

No, I was saying that the claims were saying that it did.

Who was claiming that beside you? Source?

And by the way, every tuning book or article suggests you first adjust preload, and then tune up damping accordingly.

That makes perfect sense, and I never would have disagreed with it.

It is only starting to make sense to you now that you are slowly warming up to the fact that there is a relationship between preload and rebound.

I seem to remember you camped on preload and rebound being separate and unrelated!? Implying it could have been set up independently in any sequence.

 

[Pop-Pop]

The first year (2003) ST1300 was delayed due to stability issues and replacement of the oil pan prior to delivery to the first owner.
The frame/engine bolts were also re-torqued in a very specific order to counter the instability. My first ST1300A wandered as you are describing until an inattentive deer ran into me and totaled the bike. My second 2003 ST1300A was very stable and unlike the first bike. I later bought a 2004 ST1300 standard which was very stable. There could be several things affecting your bike. Loose fork stanchions/bushings, steering stem bearings, tires, etc. Or, it could be like my first ST and wander more than it should. Just some historical FYI.

Didnt the 13 suffer from “death wobble”?

 

[Fawlty]

Didnt the 13 suffer from “death wobble”?

 

[MidLife]

.....I still thing steering effort is more sensitive to ride height, though, and will continue to guide my rear suspension height.

Whatever works for you of course.

It would be cool to have appropriate damping settings, but I'd be concerned with making things worse,

You are right to be concerned. If it halfway works for you, maybe prudent to leave it as is for now, while you learn how it all fits together. Looks like there is progress though!

 

[Larry Fine]

Who was claiming that beside you? Source?

I at least inferred it from statements such as:

I don’t adjust the damper. I only adjust the preload which works with the damper. They work together as a unit.

And many others. Now that the difference has been explained, I see it.

It is only starting to make sense to you now that you are slowly warming up to the fact that there is a relationship between preload and rebound.

I seem to remember you camped on preload and rebound being separate and unrelated!? Implying it could have been set up independently in any sequence.

Again, I see the relationship now. The cause vs effect concept just wasn't clicking.

You need to know the result of preload adjustment to set the correct damping.

If one knew the proper settings in advance, one could set them in any order, couldn't they?

 

[Larry Fine]

Whatever works for you of course.

Why would that (neutral steering effort) not be the ideal height setting?

You are right to be concerned. If it halfway works for you, maybe prudent to leave it as is for now, while you learn how it all fits together. Looks like there is progress though!

My front suspensions are not adjustable at all, as far as I know, so short of opening the tubes and changing springs, spacers, fluid viscosity and height, etc., there's nothing to do, right?

So, presuming my rear springs are where I like them for now, how do I idealize the rear damping? Look for a happy place between rebounding too fast and not rebounding fast enough?

I saw the tuner bouncing the rears, but I have no idea how what I saw would translate to how the suspension would behave while riding. I just don't have the experience or expertise.

 

[ASPC]

Speed 160km/h

Trucks running 160 KMH over there?

 

[ASPC]

One thing came to mind about the different tires is the Metzeler appeared to have a lower profile than the Dunlop. It overall looked like a smaller front tire. It’s possible those tires as a set front and rear change the geometry of the bike a little. Perhaps enough to make it more stable. Similar to lowering the front forks.

 

[ASPC]

I bought a 2004 ST1300 a few months ago. This is my 3rd bike that I rode fairly consistently. It has new brakes, tires, and wheel bearings.

I rode the bike to work today and back; an hour each way on a one-lane highway. Both times, I came to a semi truck in front of me. And, both times, as I'm riding about 200 feet (or more) behind the truck I felt a lot of buffering that I've never felt before on another bike. The buffering seemed to move the bike back and forth in the lane so much so that it was actually a bit alarming; it didn't feel 100% stable. It's hard to describe. It was like a weave or wobble, but it was ONLY when I was behind the trucks and we were going about 70mph. I did not feel this at all after the trucks turned off and I had an open highway in front of me.

Is this normal?

No it is not normal. When I had Metzeler Z8’s on my bike it was always completely stable even overtaking semi’s on the interstate at 80 plus and usually with just one hand on the throttle because I was blown around but the bike was rock solid. I put Dunlop’s back on and now it’s wobbling when I get near semi’s. The Pirelli angels weren’t much better but they were better than the Dunlop’s. I think the different brands of tire change the bikes geometry, which effects the handling.

 

[Larry Fine]

Okay, I read through the other thread again, and I had even posted in it. I also watched the track-side video again, especially the two segments mentioned, along with the guy with the 1300 in his garage.

I haven't played with the bikes since earlier because I didn't go outside today, so I don't know how either one bounces yet. But, I do grasp how compression and rebound damping each affect the suspension.

I have been riding for over 50 years, and always adjusted the rear springs to suit my weight plus any appreciable extra load. I've never had a bike with adjustable damping before, so I never learned about it.

I am familiar with the sprung-weight vs unsprung-weight concept, which looks at suspension from the vehicle's perspective. The vehicle and half of the suspension is sprung weight; the rest is unsprung.

The suspension's job is to return the wheels to their normal position quickly. Greater vehicle weight and/or lighter suspension parts give the vehicle greater control, which is why heavier vehicles can handle well.

When you go over a bump and the suspension compresses, you want the weight of the vehicle to push the wheel back down (rebound) before the compression has the time to push the vehicle upwards.

Compression damping controls the speed at which the wheel initially moves in response to the bump. Too much and your spine suffers; too little and the tire will bounce off of the road too high and too long.

Rebound damping controls how fast the wheel is pushed back down. Too much and the tire won't return to the road fast enough to maintain traction; too little and the bike will bounce you when the tire hits.

It seems to me that both really should be adjusted when you adjust one. If both are raised too far, you'll get a really stiff, harsh ride. If both are too low, the bike will float up and down with little control.

I'd like to point out that my reasoning for not believing that preload shortens the spring is because I never considered that the shock might be topped out unless it's on the center stand. I've never seen it.

I have 1100s, so I'm not aware of any suspension adjustments besides the rear spring. If there are, I'd have a new reason to learn even more about it. Can anyone tell me what the 1100 has?

 

[MidLife]

I have 1100s, so I'm not aware of any suspension adjustments besides the rear spring. If there are, I'd have a new reason to learn even more about it. Can anyone tell me what the 1100 has?

Looking at the 1100 owner's manual, recommended settings are straight forward with not much leeway to play with.

Rebound Damping Adjustment; Recommended Damping Adjuster Positions - Honda Pan European ST1100 Owner's Manual [Page 25]

Honda Pan European ST1100 Manual Online: rebound damping adjustment, Recommended Damping Adjuster Positions.

www.manualslib.com

And it goes as expected, the more preload, the more damping.

If you ride mostly unloaded, you may be just fine leaving it at 0 deg. So on the 1100, ironically, you could be just fine not worrying about it.

But just for the heck of it, you could crank up the damping until the suspension starts to "pack", just to get the feel of it.

 

[Larry Fine]

Thank you. I hadn't looked. And thank you all for the time and effort making this more understandable.

It's strange that the "standard" setting is at one end of the range instead of somewhere in the middle.

So the greatest damping is with the screw fully clockwise and softens as you turn it counter-clockwise?

I wonder why they didn't simply say start with the screw fully closed and open to soften the damping?


S

 

[MidLife]

I wonder why they didn't simply say start with the screw fully closed and open to soften the damping?

Don't have the 1100 so am not familiar with this shock.

But it would make sense for Honda to have the starting point as the position a buyer is most likely to find it when leaving the showroom (way back then).

Which is also the plushier position for a test ride....

Tuners often have the same two comments:

- Many riders will never touch their suspension settings at all.
- And those who do often get it wrong.

So some 1100 shocks may never see anything else than the 0 deg position. 360 deg could cause too much packing for a light rider and could be dangerous as a starting/default point. Better start at 0 deg.

All shocks are different. What works for one may not work with another, So there is always a "get to know your shock" period.

This one is said to have 4 positions. So it may "click" in position like some do, and don't give you an "in-between" option, I don't know.

But notice the 1/2 turn between position 1 and 2, and then 1/4 turn after that. Often it doesn't really mean that you add more damping between 1 and 2 than between the other positions. It means that the damping valve adjustment is not linear, and you need to crank it more between 1 and 2 to have the same effect than 1/4 turn between the next positions. Not uncommon with shocks and makes it a real headache to adjust: the sensitivity of the adjuster may not be the same over the whole range. Note taking becomes a must.

It's strange that the "standard" setting is at one end of the range instead of somewhere in the middle.

Still a step up from the many bikes with no adjustment at all (debatable though...). But there is a bit of a "range extender", given that at 0 deg damping, you can be on preload 1 or 2, which will also affect damping.

So the greatest damping is with the screw fully clockwise and softens as you turn it counter-clockwise?

Seems like it from the manual.