The 1098 S uses Ohlins rear shock DU511.This is a 2 way adjustable shock with a street valving spec. It uses an 80.0 Nmm spring (1091-24-80) 160MM free length.
With 23 MM of preload on the spring. Way too much
The Aftermarket DU515 shock is similar to the stock 1098S rear shock the DU511. It is different in that is is three way adjustable and already has Ohlins recommended Track valving inside.
The problem with both is when you are trying to reduce the amount of spring preload with the stock 160 MM long spring, the double nuts that control spring preload hit the side of the shock before they get to the bottom of the threads. Before we sell a DU515 shock, we take off the nuts and machine the top one to a smaller diameter and machine a bevel on to the top edge, this allows it to go to the bottom of the threads. The other nut we machine thinner, this again reduces the amount of preload on the spring allowing us to reduce the stock preload of 24MM to what we think is a more usable 12 to 16 MM.
Now we get to the top of the line Ohlins The DU788 TTX36 rear shock. This is Ohlins newest design shock. It is 2 way adjustable and has a Hydraulic Spring preload adjuster.
The 1098 Base uses a Showa rear shock, the spring has a free length of 168MM, the one I checked had a preloaded length of 142MM, and this is 26MM of preload. Way too much preload.
The Showa spring is a very progressive spring starting at 77 Nmm @10MM and rising to 89 Nmm @ 55MM. That is Bad. See graphs below.
I believe this is too much preload it should be more like 10 to 15 MM of preload.
I believe most people over 180 lbs will benefit from a stiffer spring with less preload, lighter people can simply remove some of the pre-existing preload.
I like to use 30MM of sag as a starting point for the rear. This is for the street and for the track we are now using 20 to 25MM With the stock link.
We now have a track link that allows us to go back to 309 MM of rider sag. This link adds grip and provides a better ride and controls wheeling better.
The sag is measured from the bikes wheel up in the air or with NO weight on it, this means fully extended. They the rider sits on it and a second measurement is made.
So this 30MM is the different between fully extended to with the rider on it.
Front fork springs, the 1098S uses standard Ohlins R and T fork springs. The stock spring is a 10.0 Nmm spring (4744-10).
The 1098 standard showa fork spring is exactly the same rating 10.0 Nmm.
Both are linear springs.
The 848 uses a 9.5 Nmm front spring.
I like to start with a sag setting of 40MM on the front, again measured the same way as the shock, see above.
According to the Ducati owners handbook the 1098S fork has 8MM of spring preload and the 1098 18MM. I have no idea why this would be different from bike to bike since the spring rates are the same.
The Stock Ohlins R and T forks are FG511 forks. They use a 25MM cartridge and the Showa a 20MM cartridge. Both of these are set up for street riding. For track use we recommend either a upgraded 25 MM Superbike valve and shim stack or a newer Ohlins fork that already has this same SuperBike valve kit in them. The FGRT803 forks.
For the Showa forks they can be replaced with this FGRT803 fork. This includes the 1098 Base, 848, and 1198 Base.
The Showa forks can also have the Ohlins 25 MM Cartridge kit installed. This kit also uses the SuperBike valves.
Below are PDF files on Ohlins products, they include base line Compression and Rebound settings.
I have enclosed Ohlins PDF files for:
DU511 OEM 1098S Rear shock
DU515 Track 3 way Rear shock
DU788 TTX36 Rear shock
FG511 OEM forks Ohlins 1098S/1198S
FGRT803 Forks
FGK138 25 MM cart kit Spec chart 848/1098 Base/1198 Base
FGK138 Installation manual
Ohlins spring chart Below.
Last edited by Dan Kyle; Dec 2nd, 2008 at 1:06 pm.
Hey Dan I have a DU303 Ohlins,for my 2004 Multistrada, the remote reservoir is right next to rear cylinder header pipe and heats that bad boy right up....cant be good? thats where the gas/oil goes to cool off right? Is there any type of shield for this application?
Linear Mode
