Wondering whether the wise on this board can tell me for sure whether the S4Rs (Testastretta) uses a rear suspension linkage identical with that on the 2005 S4R (Desmoquattro).
I'm still trying to get the harshness out of my S4Rs rear Ohlins on compression. Thought was to go with the DU 333 shock Ohlins offers as the aftermarket replacement for the 05 S4R. My local Ohlins contact confirms that is valved considerably softer than the OEM Ohlins on the S4Rs. But that leads him to suspect the Rs has a different linkage.
We are going to firm up the spring rate and run the stock shock with a version of the DU 333 valving that is a bit harder, and try it out.
But it would help if anybody could confirm there were no changes between the models.
I've already had one revalve done on the stock S4RS ohlins. We took some compression damping out across the board, left the same spring. Result was a significant softening of the low-speed action, with the harshness moved further into the mid-speed range and a loss of ability to soak up the biggest hits, esp two-up.
That followed a discussion I started here:
http://ducatimonsterforum.org/index.php?topic=7996.msg130987#msg130987 (http://ducatimonsterforum.org/index.php?topic=7996.msg130987#msg130987)
I'll let you know how Plan B works.
BTW: part of the reason we are going for a stiffer spring is my Monster does a lot of two-up work.
Just a quick question for you. I did not see this in your post. Did you replace the spring? Not sure why you want to go softer if your riding 2-up?
G'Day Icon,
the problem we wanted to work on initially was the harshness in the compression damping. This was felt one-up or two-up in conditions that went nowhere near bottoming out the rear shock. Sag numbers one-up were theoretically fine with the stock spring.
Softening off the damping in the first revalve got rid of some harshness, so that was a step forward. It also made it clear that without the fierce stock compression damping, the stock spring is a bit wimpy for the roads over here, and way too soft for two.
So with this change, we'll be stiffening the rear spring from the stock 10.5 to a 12.3, sticking with the stock rebound stack and fitting the compression stack from the DU 333 (looks like we'll be using the identical DU 333 spec on compression, not a firmer version as in my first post).
BTW: For those interested, I've now seen the valving specs for the DU 333 aftermarket Ohlins and the DU 5034 Ohlins supplied stock with the S4Rs, and while the spec is slightly different, the basic design, number and order of shims, etc is strikingly similar. In other words, the stock shock is not a 'second rate' Ohlins mechanically, it just uses a different valving spec. For example, on the compression side of the main valve, each uses a stack of 10 shims, and only the top four shims differ betweent the two shocks.
I'll post more about this in a few weeks when I've tried out the latest changes.
S4Rs has the same rocker part# as an S4, so from that I'd say it's the same as all '02 and later.
How much do you and your pillion weigh?
Hi Speeddog, thanks for that.
I'm about 75kg (165lbs), my passenger's 55kg (120).
So from your comments on my previous thread, we're about the same weight as you and yours.
I note you said then that your bike worked well for you two with the preload maxed out.
However, we've tried that and want more - possibly because we do more two-up riding than solo.
With the stock spring preloaded enough to give passable sag with both of us on board, there is almost no free sag and so the rear shock often tops out sharply.
Plus, it compresses too hard on big hits.
I'm looking for a setting that is great for two and okay solo.
Thanks again for your input on the part numbers - that helps a lot.
Edit: Yes, we've got a custom seat that is comfy for two.
I've got a 10.2 kg/mm spring.
I've got the sag set for me on the bike, and I'm maybe 2mm into the preload adjustment on the hydraulic adjuster.
For 2-up, I crank the adjuster all the way up.
That adds about 9mm of preload.
It's pretty good that way for 2-up.
But, I don't do a whole lot of riding 2-up, so I'm going at a conservative pace for sure.
And the roads here aren't that rough.
A 12.3 spring will be pretty good for you riding 2-up, but IMO it's going to be really stiff solo.
You may be able to find an Ohlins hydraulic preload adjuster, that'd make the transition from 2-up to solo setting a *lot* easier.
Speeddog,
I think I'll add the hydraulic adjuster to my order tomorrow. Your info on the rocker part Nos has helped with that. Sounds like we'll be close to what we want with the latest mod.
I was holding off on the remote preload thingy with the idea that eventually we'd get the DU 333 with remote compression adjuster, and sell off the stocker. I like the idea of having the compression adjuster to hand on the forward frame rail, as when the setup is right, a couple of clicks while riding can set you up a bit better for twisty stuff, while a couple of clicks softer can be better when cruising.
I think the stock spring is a bit soft over here even solo. Have certainly felt it bottom at high speed. So interested to try the 12.3. I'm hoping that if I back off the preload for solo work, will still get a good result.
I'm still a bit worried tho with your comment on the previous thread that you are on full soft with compression adjustment for your DU 333. But hoping stiffer spring and mainly two-up will sort that out for us.
If not, we can always do another refinement - ain't Ohlins wonderful.
My Ohlins man has fears the Monster linkage is dodgy. I'm hoping he's wrong. From the way the shock works on big, slow hits - dips in the road hit hard as opposed to sharp bumps hit hard - I think the linkage is okay and the valving's the issue.
I've no idea on what valving my shock has in it.
I'd like it to be more compliant on the sharp bumps; less high-speed compression damping.
I've struck a compromise by backing off the adjustment all the way, but with that the slow speed compression is a bit soft.
It's just not far enough 'off' to justify opening it up to change it.
The Monster linkage starts out at about 3:1 at full extension, down to 2.3:1 at half travel, and finishes up at 2:1 at full compression.
That's with the pushrod set at stock length.
Speeddog those are interesting numbers. Tell of a sharply falling rate rather than rising rate from the linkage. Which is just what it looks like.
Not necessarily a bad thing but nevertheless a bit of a worry and helps explain why we've had big-hit issues after softening the compression valving across the board - by going down one mm on the 'fulcrum' shim at the bottom of the compression stack.
If the effective leverage of wheel on shock increases dramatically as the shock compresses, then we need really firm valving to absorb the big hits. And if it is 50pc greater at small deflections, we need really soft valving for the little hits.
It is sounding like my Ohlins man might be on the case re the linkage. Please keep this to yourself while I sell my bike. [evil]
At least the Monster has plenty of travel to work with. Would love to hear from Ducati on this, but my contacts dont extend that far - assuming anybody there has more than half a clue on suspension, which might not be justifed.
I think you're 'reading' my numbers wrong.
It starts out at a high leverage, ~3:1, so it's soft near full extension.
Then the leverage drops, s it's stiffer at full compression.
Hmmm, 1:1 would be the shock mounted vertically on the swingarm near the rear axle with no linkage at all. 3:1 would be like having the shock 2/3 toward the pivot with no linkage.
So at the higher ratios, axle movement compresses the shock less. Which means slower. So I guess you're right, and the rate rises with compression. Which means there's reason for hope.
If I can get the rear suspension working as well as the front, I'll take back my slur on Ducati's suspension people.
Thanks again for engaging.
You've got a pretty tough dilemma, trying to get it set up for both solo and 2-up.
IMO, you can get a good compromise setting.
The hydraulic adjuster will help a good bit.
Let us know how it works out. :)
Okay, sorry for the long wait, but have posted long report on the modded set-up here:
http://ducatimonsterforum.org/index.php?topic=31701.0 (http://ducatimonsterforum.org/index.php?topic=31701.0)
Short version: big improvement all round, stiffer spring still okay solo, agree mid-speed compression damping still firmer than ideal but DU 333 valving much better than stock.