Suspension upgrade question

[diamonddog-2]

So the 2001 M900Sie project is coming along. I got the Arrow slip on exhaust mounted. Got the carbon fiber cowl/upper fairing , windshield and belly pan fairing mounted up.  Almost finished with the full service. I also found what I hope will be an upgrade in sticky tires [going from the older Michelin Pilots to a set of Dunlop Sportmax Qualifier] for fair price
Now I'm working on a couple of updates for the suspension.  New valves, springs and oil will be done to the adjustable forks.   I'm wondering about the rear shock.  I'm not sure if my riding style would demand a huge [expensive] upgrade?  I was thinking about a Ohlins DU 044 that seems like a good value for the street riding I do. The adjustability doesn't seem to be all that important like the  the Ohlins DU 440 would provide. The 044 is also about 60% of the cost of the 440
The bike has 31K on it but is still just a freakin grin machine.     It's in great shape and worth putting a few $ into where needed. I'm hoping to feel a little more secure on cornering and twisty roads with the tires/suspension upgrades.   A craigslist guy has a Sachs shock off of a 01 900ie that had 6K on the bike....but it looks different than the one on my 01.  The one for sale has a piggy-back reservoir on it with a black dial on the top. I assume it's for adjusting the damping ?   I'm just not sure going from my stock Sachs to a different Sachs with more adjustability is an improvement? $150 for the Sachs  $600 for the Ohlins 044   $1000-ish for a 440

What do you, oh great and powerful duc wizards, think of the above?  Any thoughts?

Thanks!

[Speeddog]

I'm pretty sure that Sachs is from an SS and it's not going to work.

I'm currently running a Penske emulsion shock on my M750, it's an excellent shock for the $.

[diamonddog-2]

Thank you Speeddog.  I had been looking at the Ohlins in order to keep the suspension more like a later model S M900. I believe they came stock on them?.....however cash funds being what they are,
and now, after hearing first hand about them, I'll take a serious look at the Penske as a substitute for the Ohlins.

Just curious. Can the Penske be rebuilt if needed....like the Ohlins?  Maybe they're not all that expensive to replace?

Thank you.

[ducpainter]

I run the DU-440, and like it a lot.

I do use the compression damping adjustment. Our roads can require some adjustment over the course of a ride.

[Speeddog]

Yes, some later 900's came with the Ohlins, had a remote reservoir on a hose.
Reservoir fit under the rocker on the crossmember, with a special bracket.
You could get an Ohlins and replicate that configuration.

Penske can be rebuilt, revalved, etc. same as Ohlins.

Either shock will be markedly better than what you have right now.

Most of the Ohlins that I've run across, OEM or aftermarket/off the shelf, have valving that's got too much compression damping, IMO.
And the external adjustments won't fix the issue.
I had one of the M900S OEM Ohlins on my M750, and I opened it up twice to alter the shim stack.
Then I got the Penske, bolted it in, and the single adjustment knob got it 99% as good as my revalved Ohlins.

The advantage of the Penske is that they're custom making it to your order.
IMO, this allows them to get it much closer to 'right'.

They're both good shocks.
I've talked to a number of suspension gurus that say "Penske (Ohlins) is the bomb, that Ohlins (Penske) stuff is shit!". 
The way Penske does things makes more sense to me.
But there's tons of Ohlins stuff out there, so I've gone to a good bit of effort to figure out how to make them work well.

I've not tried an 044 Ohlins.
There are folks here that have them and like them.

[diamonddog-2]

Thank you ducpainter.  I gotta admit, I've just never fooled around much with the adjustability on my shocks much. Maybe a simple pre-load adjustment with 2 up riding......but then again, I've never owned a Ducati with front and [possibly]  rear adjustable suspension either.  If it was somebody else's money, I'd tell 'em to go big or stay home, on the porch with the little dogs!    

Thanks again Speeddog. I like the voice of experience.  I looked on ebay for Ducati Penske shocks but nothing popped up for fitment on my bike. I'll keep looking around for one to compare. The 044 is closer to my budget of around $500

[S21FOLGORE]

The advantage of the Penske is that they're custom making it to your order.
IMO, this allows them to get it much closer to 'right'.

Totally agreed on custom made rear shock. They are worth their weight in gold.
I have had Fox, Works Performance (sadly, they closed down recently) custom built shocks in the past, and have Ohlins DU-333 (which I believe only available as custom made) on my S4R now.

To me, it (custom rear shock) is a "must have" because I weigh only 125lb.

Well, my case is a little bit too extreme, but, the rear shock that has correct spring rate and valving (for your weight and riding style) is worth spending extra money (and waiting time).

So, if you are thinking spending $500 for off the shelf stuff, I would say order this one
(This is the one Speeddog mentioned.)
https://www.penskeshocks.com/product/8900-emulsion-single-adjustable/

yes, it's going to be $700, $200 more than you would like to spend, and it's not the flashiest one, but,...

it is going to be made to your spec (rider weight, riding style, etc)
it is user rebuildable. (You can service / rebuild by yourself)
8900's PDF manual


If you are going to keep the bike long, I think you will be a lot happier with this in a long run.

[diamonddog-2]

Thanks everybody. I always appreciate the input from experienced Duc riders.  I just have to ask, is the difference in custom shocks really THAT much?  ["worth their weight in gold"] I've ridden stock suspension, then switched to Fox on 1 bike, upgraded to Power Works on 2 others [R.I.P.?   ] and sure, I felt the difference. However, it sounds like off the shelf isn't all that much better than a stock shock, whereas a "custom built" is almost, like, worlds ahead?  I'll spend the dough if you guys think the ride difference is that much better than something off the shelf.  I mean, I'm strictly a street rider with maybe a 'come ride at our track school for the weekend to be a better rider' on the horizon next year.  I just want to get better at riding....even after 40+ years of 'scoots.  I know it's possible to spend a lot of $ on the shock but for my street riding style, the question keeps coming: is it worth it?

Last weekend, I talked to a service guy at Omaha Ducati who had suggested the DU 044 Ohlins. He had said they would set it up for my correct weight, etc. before shipping it out. Does that sound like the same thing that Penske would do or might there be a difference in how the either would be prepared?  If set up for my weight, figure there's much difference between the 2?

I LOVE my Ducati and don't see parting with her anytime soon [heck, I had my BMW K100RS for 21 seasons] I just get a buzz from how the S sounds and how it feels when I crank on the throttle. Next, I wanna ride wheelies.....maybe. 

Thanks for the discussion

[S21FOLGORE]

“Worth its weight in gold” ?
To me personally, yes.
Being featherweight, nothing off the shelf works for me.
You know what it's like to be 125 lb? When I sit on the brand new Ducati, the rear suspension doesn't stroke at all.
I would be riding a bike with rear suspension always topped out (that would induce rear tire sliding out at the corner) if I don't get custom made rear shock.
Too stiff spring doesn't inspire confidence. I would be riding with zero feedback from the rear tire with the stock shock. Not fun, and not safe.

Now, if you weigh somewhere around 150 - 160 lb. spring  in the stock shock or off the shelf aftermarket shock may work.
However, if you are, say 175 lb and the stock shock is designed for 145lb to 180 lb, you may be at the end of adjustment range when you set up the suspension for your particular requirement. That will limit what you can do with the suspension set up. Also, the shock is not performing at its best.

As for Ohlins vs Penske, I would say, get the one you like. The price, the look, the color, whatever the reason, if you like one better than the other, buy that one.
Or, if you know any local suspension specialist, and he's selling either one of the brand, you can order through him.
They both ask your weight (fully geared), riding style (track, street, both (which can be tricky)), and you may add more info (eg, carrying a passenger frequently). So, yeah, both Penske 8900 and Ohlins Du 044 would be made / set up in the same way.

I just remembered that I actually have Ohlins on my NA6 Miata, too.
IMG_0681

So,... I guess I'm a Ohlins fan.

[diamonddog-2]

Ohlins fans are everywhere! .....  whether they realize it or not?

But seriously, I guess it didn't occur to me how your weight of 125lbs would completely throw off the suspension. I weigh anywhere between 180 - 190 and just figured most suspension would be fine.

It was just brought to my attention that there's a Duc "specialist" in my area. A guy named Doug Lofgren.  He may be helpful in dialing in my front and rear suspension as well as the engine. It backfires a bit. Maybe that's normal for Ducati with K&N filter, Arrow slip-ons and a Power Commander?....

Anyway, you guys have given me a couple of different ideas to mull over, improve the bike's suspension and maybe not break my budget.    Penske vs. Ohlins  Custom shocks vs. off the shelf.  It's good to have choices.

[Speeddog]

Depending which year and model, you're going to get different levels of benefit from aftermarket shocks.

The aftermarket Ohlins that I fitted to my S4 was better than the stock Sachs.
But it was definitely not optimum.

Typically Ohlins shocks are offered with the 'correct' rate of spring installed, but still a baseline valving setup.
Penske comes with both the spring and the valving assembled to what they think you need.
You may like something stiffer or softer.
As S21 said, if you're ~150 lbs, you're reasonably matched to the OEM suspension on Gen1, 2, and 3 Monsters.

I don't race, I ride street.
I work to tune them for best performance on the street.
Maximum bump compliance while preserving a relatively stable platform.

Race setup is working towards lowest laptime while not abusing the tires.
Different goals.

Just because you're not racing doesn't mean you don't deserve good suspension, or won't be able to tell the difference.

[koko64]

My track bike is very very firm which is perfect. It would be excruciating on the road.
My street bikes are set compliant for our crap roads.
The rear Ohlins on my M900 is on minimum comp damping for the local potholes and ruts.

[Moronic]

My experience with Ohlins is a match for Speeddog's.

And from his experience with Penske, it sounds like they have a better handle on what valving works well for a typical Duc on the street.

More generally:

- The ride is controlled mainly by the valving on the main piston, which is on the end of the shaft and hidden away in the body of the shock. That valving relies on a stack of shims which have successively smaller diameters as they rise away from the piston. The shims cover carefully designed holes in the piston, and collectively bend under pressure to let the damper fluid flow past. The design gives you damping that is progressive: the shim stack opens further under big hits than small.

- A shock manufacturer or specialist can adjust the ride by substituting different shims, or a different combination. But it's essentially a suck-it-and-see process, guided by past experience. And they have to pull the shock apart to do it.

- The external adjusters have a minor effect by comparison.

- Usually, the external rebound adjuster controls entry to a bleed passage that allows fluid to bypass the main shim stack. Because the bleed passage at any particular adjustment is a constant size, there is no progression. So you don't want that passage to be very big, by comparison with the main valve. Consequently its effect is always marginal. (Although very noticeable as fine-tuning if the main stack is about right.)

- Typically, the external compression adjuster is even weirder: it controls the rate at which fluid moves from the main part of the shock into the remote reservoir. Fluid goes there as the shock shaft moves deeper into the shock body. Because the shaft takes up space, and shock fluid is not compressible, the fluid has to go somewhere. It goes into the reservoir - but only as much fluid as the shock shaft displaces, which is not much. Generally, there is some progression in the valving here, but the valve is still very small compared with the main valve, and so once again it is good for fine-tuning only.

Add it all up and you are relying on the manufacturer to get the main valving right. They will use a shock dyno, which can measure the resistance of the shock under rebound and compression over a range of shaft speeds. Doubtless they also have mathematical modelling which helps.

But given the big number of bikes out there, it is not likely they do much (or any) field-testing on most bikes. And different bikes put the shock in various places, and use various linkages that affect shaft speeds in various ways.

Finally, even if they did test everything extensively, what their tester liked and what you like might differ.

I've gone into all that detail just to help answer your questions about the benefits of various shocks. I thought the background might give you some perspective.

Generally, going from stock to Ohlins or Penske will bring you a better main valve - more progression and more subtlety. That's even without adjustments. If you get an adjustable, then - all else equal - the adjustments will also be much more effective and precise than on a stock adjustable.

In reality, whether you realise those theoretical benefits will depend on how well the main valving works for your application. In other words, on how close is the manufacturer's best guess to what you really need.

Which brings me to the final benefit of a good aftermarket shock: you can work with a suspension shop to get the main valving adjusted, and the available range of adjustment is very wide. But as Speeddog notes, you can still end up dissatisfied. In which case you can try again ... and again. (See my sig line for - a lot - more.)

The happy ending is that once you do get it right it can be almost unbelievably good, and it will stay that way (albeit ideally with a service every 20,000 miles or less). Will you notice the difference from stock? Certainly. Will it be worth all that trouble and expense? Your call there.

Again in general, the harder you ride, the more benefits you will notice. But you don't have to ride at track speeds to notice. Broadly, the key difference will be that the bike seat no longer bounces up and down in response to the road. The seat, and you on it, stay steady, while underneath the wheel moves up and down just as much as required and no more. That means the steering geometry stays steady too, so the bike steers very precisely. It's a remarkable feeling. But unfortunately, even an expensive aftermarket shock can't guarantee it.

[silas]

I have the DU044 Ohlins on my 98 M900. Havent messed with it since installation. Only $600 or so. Big improvement over oem shock (before it blew its seals at 35k miles & its used replacement blew also). I have about 3000 miles on it now. Feels less harsh. I got it from Hippie at Racing Sport Services in Braselton Ga. The improvement was realized even more after I recently had my adjustable forks re-sealed, re-valved, and set up by an expert (GMD Computrak). The bike now feels somewhat stiffer for the curvy roads, as desired.

[greenmonster]

My experience (and waving a blue-yellow flag ):

1. M900 -97:
a. Big difference w just getting an Öhlins spring for my weight on the Sachs.
b. Got a 046 from a 851, switched over spring, dialed preload, set standard settings-done!
  Just works, not harsh, you just forget it`s there cause it just works.

2. 907IE:
a. Penske, 4way fully adjustable, fine shock, works very well.
b. 046 w correct spring, see 1b….

3. MTS 1100:
a. Original 3way Sachs, surprisingly worked quite good!
b. Öhlins S46, 3way, original, little soft spring.
  See 1b….

Maybe try correct spring first? Big difference, original way soft, you could ride w less rebound.
But you won`t be unhappy w the 044.