Ducati Monster Forum

Moto Board => Tech => Topic started by: JonS2R on July 14, 2018, 09:30:25 AM

Title: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on July 14, 2018, 09:30:25 AM
Hey guys, I'm working on getting my suspension dialed in and have some observations I want to run by you guys. I've spent a lot of time over the years reading suspension guides but I still feel like I only have a slightly better than basic understanding of this black art. My prior bikes were an SV650 and VFR800 so the Monster is definitely the nicest and most sensitive suspension I've had to adjust (excluding my mountain bike).

I weigh 155 with no gear, the shock is stock, and the forks have .9 springs and 7.5wt fork fluid from the prior owner. Although I would like to hit the track someday, my riding consists of commuting to work and joyriding on back country roads so my preference is more towards comfort rather than performance. I only have myself to help set up preload so my measurements probably aren't quite as perfect as if I had helpers but I want to at least get it in the ballpark for now and then I'll take it to a shop for help if I really need to.

I finally had time to go riding around today with a screwdriver so I could make adjustments on the road. I put zip ties around one of the fork legs and shock shaft to get an idea of how much suspension travel I was using. I set it while riding back and forth over a particular section of road that has a couple bumps and dips with sweeping corners I can comfortably take around 50-60. I chose this road because I used to commute on it and have spent a ton of time riding my prior bikes over it so I thought it would provide a good base line.

Forks:

Racetech recommends .9 springs for my weight for street riding. With the preload adjusters dialed all of the way out, I'm measuring about 23-25mm of sag, slightly less than the common street recommendation of 30mm. I've been riding for the last month or so at stock rebound/compression settings just to get a feel for the bike since it's new to me. I got a lot of road feedback through the bars that I've had to absorb with my arms, even on seemingly smoother roads. I also noticed the reflections of my headlight constantly bouncing and flickering as if the suspension isn't really absorbing road imperfections. Removing 3 clicks of compression and adding 2 clicks of rebound hugely improved comfort and feel and seemed to get it pretty close to what seemed like the sweetspot while I was riding the above mentioned road. The front end felt smoother and my arms were much more relaxed over rougher pavement. It didn't feel like the forks rebounded too much when coming to a hard stop either.

After getting home, I checked rebound by pushing down on the front end of the bike and watching the forks rise. They come back up pretty quickly and in one movement will briefly extend passed their stationary position and then settle back down. This would indicate more rebound damping is needed but when I added even 1-2 clicks more rebound while out riding, the front end felt a little less comfortable. I know you can't have ultimate comfort and damping at the same adjustment point but again I'm leaning more towards comfort in my settings.

My main question on the forks: The zip tie I put on the fork leg stopped almost 2.5" from the bottom indicating a lot of unused suspension travel. I know not all travel should be used during normal riding but shouldn't I be going through more of it? That plus the maximum sag I obtained above makes me think that maybe the .9 recommend springs are too high of a rate. Should I try .85? Or would it be better to try cutting down the spring spacer to remove even more preload than the adjusters allow? The prior owner looked to maybe have 20 pounds on me so I'm wondering if the spacers he used were short enough to get within his sag setting but too long for mine. It probably doesn't help that my weight tends to fall right in between the .85 and .9 spring rates or at least it did on my prior bikes. I also have the OEM springs if those are worth trying but then the front end would likely be too undersprung.

Shock:

The prior owner didn't have much preload dialed in when I first bought the bike. There was maybe a 1/4 inch of thread showing above the locking ring for the shock collar. The bike sagged a lot sitting on it and I could almost flat foot the bike at 5'6". The rear end would sit down a lot under acceleration and took a bit of effort to flick side to side through back to back curves. It felt ok going over bumps in the road but riding through dips caused what felt like harder suspension hits. It initially had about 50mm of sag when I measured. I've got the preload collar a little bit past the halfway point of the threaded section on the shock body which gave me about 10mm of static sag and 35-40mm of sag when sitting on it. Again, I'm doing this by myself so I'm just trying to get it within an acceptable range for now. I set the sag about a week ago and it still felt like the bike was sagging a bit too much when sitting on it compared to the front and I could still feel it sitting down a little under acceleration.

Before I went riding today, I increased preload even more by about one full revolution of the collar just to see how it would feel. This definitely helped as the bike noticeably sat higher. I'm now on the balls of my feet when stopped rather than almost being flat foot. It turned sharper and stayed flat under acceleration which threw me off at first as I thought the bike suddenly wasn't accelerating as hard although really the back end just wasn't sitting down like I had been used to. Rebound is 15 clicks out from all of the way in and it seems to be riding pretty good at this point. I'll have to try measuring preload again at this setting to see how much sag has been reduced from my prior measurement.

After riding, I checked the rear rebound by pushing down on the seat and watching how the bike responded. It doesn't seem to extend passed it's stationary position but did seem to oscillate twice before settling. Again, this would indicate more rebound should be added but doing so while riding caused me to feel bumps in the road more so than less rebound.

My main question: is it normal for someone of my weight to have the preload collar turned down so far? Racetech shows a recommend rear spring rate of 8.5 kg/mm with the stock spring being 7.4 so I know the rear is a but undersprung. It just seems weird having to turn the collar so far down when I didn't need to do it as much on my prior bikes. The zip tie shows I have about 10mm of travel left before I hit the bump stop. I know the rear linkage is progressive so it's going to take harder hits to push it further through the travel. Would it be worth swapping the shock spring out? Or should I leave it as-is if the sag is around 30mm? I ask because I've read that it's preferred to hit your sag with as little preload as necessary...

Thanks if you actually read my entire rambling post. I'd love to hear how anyone of similar weight has their suspension set up.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on July 14, 2018, 09:53:07 AM
Crap sorry, I meant to post this in the Tech section  [bang]
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Speeddog on July 14, 2018, 11:46:04 AM
That's way too much front spring for your weight.
I'd say 0.80 for comfort, 0.85 for sporty.
There's a number of ways of getting closer to those depending on budget.

The stock rear spring is a progressive one, it can work OK for you.

Get the front sorted out first.

Dunno what's up with those RaceTech numbers.
A 10 or 10.5 would be good for the rear.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: BK_856er on July 14, 2018, 11:56:27 AM
You're doing the right things, but don't trust that racetech calculator!

@155lbs, I think you'd definitely be better off with 0.85 or probably even 0.80 fork springs.

Best to report two sag values for both ends:  sag without rider, sag with rider.  The first requires the bike to be first fully supported by lifting the rear off the ground or the front by pivoting on the sidestand.  On the rear you'll also have a third value of free sag, which at least for a straight-rate spring can be an indicator of correct spring rate - need a bit of free sag.  Sag numbers are tricky without a helper, not only the measurement itself also but factoring for stiction.

FWIW I'm about 165lbs and use 0.85 fork springs and 625 shock spring, aftermarket suspension and straight-rate springs.

Is there a good suspension guy you could ride to?  A decent baseline is gold.  Otherwise keep notes and don't be afraid to make adjustments.  Owner's manual might also indicate the delivered settings for reference.

*edit - speeddog beat me to it!

BK
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: stopintime on July 14, 2018, 12:21:11 PM
I can't see how a linear shock spring wouldn't make you happy. The very same about lighter fork springs.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: BK_856er on July 14, 2018, 01:00:13 PM
You also mentioned ride height and the PO already changed fork springs.  Worth confirming fork tube position and ride height adjuster length so the chassis geometry is at a known starting point.

The factory fits progressive springs to accommodate a very broad range of customer weights and I suppose 2-up scenarios.  Linear springs (aka, straight-rate) will always be superior, especially when used at both ends.

I don't have an S2R1000 and its better parts, but the best thing I ever did for my M695 was to sort out the suspension.

BK
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on July 14, 2018, 02:13:10 PM
Quote from: BK_856er on July 14, 2018, 01:00:13 PM
You also mentioned ride height and the PO already changed fork springs.  Worth confirming fork tube position and ride height adjuster length so the chassis geometry is at a known starting point.

The forks are about 7mm above the top of the triple measured from the top of the fork cap (not the nut). I say "about" because I did measure it when I first got the bike but forget the exact number so I'll have to check again. I just checked the manual and didn't see it specified as to how high above they should be unless I just missed it.

The rear height adjuster has no threads showing so I think that means it should be at stock height.

Can someone confirm?
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on July 14, 2018, 02:16:46 PM
Thanks for the input on spring rates. I thought that seemed too high for my weight. My VFR also came with .9 springs and the front wouldn't compress at all when I sat on it. Putting the stock springs back in made it ride great. I had .8 springs on my SV but they still almost bottomed out under hard braking so I swapped them to .85. Of course that bike is also notorious for having awful forks regardless.

I suppose I'll need to get a front stand and spring tool now.  [thumbsup]
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: BK_856er on July 14, 2018, 08:08:54 PM
Most of the "owner manuals" can be found with a quick google search.  It might have info on the initial suspension settings, FWIW.

The much more extensive "workshop manual" can sometimes also be found for download if you work at it, or I think the CD can be purchased from Ducati.  For example the S2R800 manual shows 25mm shock spring preload, 261mm rear height adjuster length and fork tubes flush with top triple (again, FWIW).  S2R1000 might be different, no FHE from me.

Getting the front spring rate right for your weight should be the top priority, but some of the other stuff is "free".

Good luck!

BK
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: DuciD03 on July 18, 2018, 10:02:51 PM
 
[popcorn] !!!

okee .... this is something I know little about; but want to know more about and do; what you just wrote explains a lot about suspension setup; thanks!  [bow_down]

You got good comment back; you'll get er dialed in right.

[thumbsup]
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on July 19, 2018, 04:43:38 PM
Quote from: BK_856er on July 14, 2018, 08:08:54 PM
Most of the "owner manuals" can be found with a quick google search.  It might have info on the initial suspension settings, FWIW.

The much more extensive "workshop manual" can sometimes also be found for download if you work at it, or I think the CD can be purchased from Ducati.  For example the S2R800 manual shows 25mm shock spring preload, 261mm rear height adjuster length and fork tubes flush with top triple (again, FWIW).  S2R1000 might be different, no FHE from me.

Getting the front spring rate right for your weight should be the top priority, but some of the other stuff is "free".

Good luck!

BK


Found it. Funnily enough, they specify fork height by measuring from the top of the top cap to the bottom of the lower triple clamp. 296mm +/- 1mm. I'll have to measure when I get a chance...
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: caperix on July 20, 2018, 06:43:51 PM
I also think at your weight a .90 spring is too much.  I have .85 springs in my bike & the preload is almost all the way out, I am about the same weight as you.  Removing space will only help is too large a spacer is installed, removing too much will just lower the front end. 
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Moronic on July 24, 2018, 05:50:06 AM
I'm about 180 without gear. In the front for my S4Rs (same basic chassis) I run a .85 on one side and a .90 on the other. This feels about right, and my riding priorities aren't far from yours.

So you should be a bit softer, but 0.9s at your weight should not be the end of the world. I have run 0.95s, and while they left me a bit short for feel the ride was still good.

Ideally the front of the bike won't respond to bumps with much vertical movement. I wonder whether something else is contributing in your case.

From what I read, the damping circuit in the S2R1000 fork is not terribly flash. I don't know what fork fluid is recommended but 7.5 weight sounds high to me. What do other people use in these?

I would not pay great attention to the results you get from bouncing a stationary bike. It is the damping when you take sharp hits at speed that will matter most, and that could be very different from the low-speed static feel.

Remember you also have the air gap to play with. You can run a soft set-up and adjust fluid levels to preserve some travel under hard braking.

It may also be that you have more fluid in the fork legs than you need (small air gap), and this is part of why you don't use all the travel.

At the rear, I use a 10.0kg/mm spring. It is great and I wouldn't want softer. For your weight, I would guess 9-9.5.

I can't believe stock is 7.4 - are you sure it is the same unit?

OTOH, if it is working then why worry? It is the practice that counts, not the theory.

Your  rear sag numbers sound pretty close to me. And you are still not bottoming the shock. You have plenty of unladen sag at 10mm, so just add preload if you want some more ride height.

Most people find these chassis feel more neutral with the ride-height adjuster rod screwed out three or four turns.



Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Slide Panda on July 24, 2018, 07:32:08 AM
As noted, .9 fork springs are way too stiff for you. For another data point I'm 185-190 sans gear and run .975 (one .95 and one 1.0) for fast track day work.

Regarding the zip tie - that's only going to bottom out, or get close when one is braking hard, or you hit a significant bump, even with properly set up suspension. So in your case, even with softer springs swapped in, I'd not expect to see the tie at the very bottom
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on July 24, 2018, 08:56:37 AM
Quote from: Moronic on July 24, 2018, 05:50:06 AM
I'm about 180 without gear. In the front for my S4Rs (same basic chassis) I run a .85 on one side and a .90 on the other. This feels about right, and my riding priorities aren't far from yours.


Interesting, I've never seen anyone mention running different weight springs in the forks. Any particular reason for it?
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Moronic on July 24, 2018, 02:57:10 PM
I think I had gone back to the stock springs but had bought the 0.9s. A fork seal blew on one leg, and so I had the spring replaced with the seal.

The result was so good that I have left it that way.

I believe spring combinations are used a fair bit by people seeking precision - note Slide Panda's post above.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: danaid on July 24, 2018, 03:49:05 PM
OP needs to get to a track day event and have a suspension tuner set the bike up while riding on the track!
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Speeddog on July 24, 2018, 06:00:51 PM
There's someone here using one linear and one progressive spring too ......
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Howie on July 24, 2018, 09:53:14 PM
Quote from: Speeddog on July 24, 2018, 06:00:51 PM
There's someone here using one linear and one progressive spring too ......

Interesting.  I'm not really against progressive springs, more Ducati's choice.  Way to soft 'till near the very end.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on September 12, 2018, 03:57:42 PM
Quote from: danaid on July 24, 2018, 03:49:05 PM
OP needs to get to a track day event and have a suspension tuner set the bike up while riding on the track!


For sure! Though that may have to wait until next year most likely  :(

I'm going to put the OEM springs back in for now to see how they feel. Do you guys happen to know the length of the OEM spacers?
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on May 23, 2019, 05:34:33 PM
I figured I'd update this post as I work on the suspension.

I swapped a Multistrada 1000ds rear shock in a couple of weeks ago. I know guys normally use the 749/999 shock but I got the MS shock for super cheap so I figured it was worth a try. It has compression and rebound adjustments as well as remote preoload. It's about half an inch shorter than the OEM shock so I had to raise the rear to compensate. I started with the baseline setting recommend for the MS and even at that point it rode sooo much better. I haven't had much time to ride it to get it dialed in though. I still need to find a good way to mount the remote preload knob. Right now I just have it zip tied to the frame  :-[

The downside is it really brings out the weakness in the forks. I did end up swapping the OEM springs back in not long after making this post. They're better than the heavier springs that were in there but I'll swap in some springs for my weight sometime soon.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: koko64 on May 23, 2019, 08:10:19 PM
 [thumbsup]

Its common to notice how bad one end is when you've fixed the other.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Speeddog on May 23, 2019, 09:56:14 PM
I would imagine there's a bundle of different brackets for mounting an Ohlins preloader onto most anything, perhaps the ADV folks have something?
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on June 15, 2019, 02:22:18 PM
Ok so I figured I'd order springs now. I was planning to go with the .80 rate but Racetech only goes down to .85. Traxxion only carries .90 and Sonic Springs doesn't carry anything for the 1000 (even their S2R800 springs only go down to .85)

Does anyone have another source for springs?

Quote from: Speeddog on May 23, 2019, 09:56:14 PM
I would imagine there's a bundle of different brackets for mounting an Ohlins preloader onto most anything, perhaps the ADV folks have something?

I ended up just buying the OEM bracket for it and will source some type of L bracket to mount where the pegs are and then will mount the adjuster to that.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Speeddog on June 16, 2019, 12:21:22 AM
I guess all riders are over 170 lbs now.
We're both SOL then.
I never thought I could become even more disappointed with R/T. A new low.

You could get the 0.85's and run only one, with the other an OEM progressive.

On my M750, I'm running an S4 spring in one leg, IIRC it's a 0.86, and an OEM progressive in the other.
The rest of the forks are the same sort of mix n match of bits... so not OEM at all.

Brad Black did quite a bit of work with OEM progressives using more preload and less oil.
He's got blog posts in the December 2013 to May 2014 dealing with it.
http://bradthebikeboy.blogspot.com/2014/05/showa-43mm-adjustable-fork-design-and.html

Quote from: howie on July 24, 2018, 09:53:14 PM
Interesting.  I'm not really against progressive springs, more Ducati's choice.  Way to soft 'till near the very end.

Yes, with OEM preload and oil level, they're awful.
Unless you're 140 or so, then they're just crappy.

It's been quite a while, I'll dig through my notes and get some more concrete answers.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: JonS2R on June 17, 2019, 07:15:14 AM
Hmm, do you think I could get away with running one .90 spring? Since I still have the set that came on my bike...

Thanks for all your help!
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: Speeddog on June 17, 2019, 09:32:14 AM
Quote from: JonS2R on June 17, 2019, 07:15:14 AM
Hmm, do you think I could get away with running one .90 spring? Since I still have the set that came on my bike...

Thanks for all your help!

IMO, it would certainly be better than running two .90's, or two OEM.

I hesitate to recommend it, not knowing how you're getting fork work accomplished.
If you're paying a tech to do it, then I think that a 0.9/OEM is not the best place to start, as it might take yet more internal fiddling to get it 'right'.
If you're DIY and game to spend the time, then go for it.

<rant>
Take specific and detailed notes of what springs and oil you're running, damper screw settings, how it feels when you ride it with those settings, etc. etc. etc.
Make your best effort on this, it is unlikely that you can take too many notes.
If you do not, it is nearly impossible to avoid getting lost and thus making wrong adjustments and wasting resources.
I've been doing R&D testing as part of my job for over 3 decades, my FHE is that crappy/no notes = you're make the beast with two backsed.
I see amateur racers that run season after season with no log book at all, so they've no accurate records of when what was done, nor what settings used, or results.
No checklist of what equipment to bring, no checklist of what pre-race tasks need to be done.
They have no idea why the bike doesn't behave the way it used to or why it breaks down all the time.
Honestly, it's an absolute disaster.
And zipties as structural fasteners....it makes me weep.
</rant>

There's a couple of annoying traps you can fall into with running different springs in each side:

Your forks have top-out springs in them; small springs in the damping cartridge that keep the fork from topping out with a clank.
With the front wheel not supporting any weight, as you add/remove preload, the forks will extend/retract a little bit, as you've got springs pushing against each other.
Different rate springs make the forks extend/retract different distances for the same # of turns on the preload.
So even moderate changes in preload can make it really hard to get the axle in or out.
Countermeasure:
Install the forks at the same outer tube height, with zero preload.
The stiffer spring's preload adjuster is the 'master', and the softer one is the 'slave'.
Fit the axle *only*, adjust the 'slave' preload such that it slides in and out easiest.
*Write that setting down* IE master 0, slave 1/2 turn.
Run the master preload in a couple turns, adjust the slave again.
"master 3, slave 4 3/4" (or whatever)
Step up a couple more times.
Finally, run the slave all the way in, and adjust the master.
"Master 13 1/2, slave 17"
That's your max.
You've now got a table to refer to for settings.
With that, you can avoid a lot of aggro and fuxxored parts.

Set the total length of the springs + spacers the same each side, as OEM and aftermarket springs are almost never the same length.

Racetech springs are often a bit smaller diameter on the inside, and they hang up on the plastic cup gizmo that's on the damper rod.
Remove said cup if that's the case.
Title: Re: S2R 1000 suspension adjustment: rambling thoughts and questions
Post by: koko64 on June 18, 2019, 08:10:29 AM
Awesome advice [thumbsup]