Ducati Multistrada 1200 Ohlins / DES Suspension Information

See also: Ducati Multistrada 1200S ‘DES’ Suspension
(download the Ducati Electronic Suspension (DES) settings spreadsheet)

See also: MTS 1200 ABS Operating principle of the electronically adjustable suspension (PDF download 515Kb)

See also: Failure modes of the electronic suspension (external link)
A discussion on the Ducati.ms forum on what does / does not happen in the case of any failure of some aspect of the Multistrada 1200’s electronic suspension control system.

See also: Ducati DES vs BMW ESA

Ohlins Forks (MTS1200S Sport & Touring models
Instructions / guide for dismantling and servicing the Ohlins front forks on the 1200S model Multistradas. The following document is actually a Ducati Service Bulletin (No. 888 / TSB 14-002 02/2014) relating to the ‘recall’ of certain bikes in relating to an issue with the right fork bottom end but describes the dismantling / service procedure.
mts1200_ohlins_right_fork_ducati_service_bulletin_888.pdf (2.20Mb)

Ohlins Shock Schematics / Spare Parts
Shock TTX36 EC Ducati Multistrada 1200 S Ohlins TTX DU8600
(PDF download 974Kb)
CARE: Important, note that the part number listed for the rear spring is for the stronger spring not the OE Multistrada 1200 item.
The stronger spring is for ‘heavier’ riders, or those who are above average weight and also tour two up.I found that to ride solo the bike was best when set to rider + luggage. When two up fully loaded it was too soft. With the stronger spring it is just about right. Only cost around £70 too. [JohnW]

Multistrada 1200 / MTS1200 Rear Shock Removal / Fitting
After an enquiry relating to fitting the upgraded / stronger spring here’s an extract from the Workshop Manual on the removal and installation of the Multistrada 1200 rear shock absorber unit. **NB** this is taken from the ‘draft’ 2010 MTS1200 workshop manual – there may be differences to the instructions in the final version of the manual (but due to it’s format it is not easy to reproduce extracts here – I have not compared the instruction….I recommend you obtain the final version of the manual;-)
Multistrada 1200/MTS1200 Rear Shock Removal/Fitting (PDF download 1294Kb)

Ducati Multistrada 1200 DES Suspension Primer
By Ducatisti.co.uk member ‘Torxhead’ (aka Scott) 02Aug2010

I spoke to Ohlins USA rep Matt Sage (828.692.4525 x308) on July 30, 2010 to learn what I could about the Ducati/Ohlins DES suspension system. Matt was extremely helpful; I’ve been searching the web for information on these particular units, but he said that because DES is a Ducati product there is no Ohlins manual. He also said that Ducati probably wouldn’t be able to offer much information.

Forks
The DES forks employ one leg for rebound damping and one for compression damping, necessitated by the fact that it would be overly complicated to control adjusters at both ends of the fork. Ohlins refers to this system as NIX on their own products (they have no complete retail NIX unit, but all of their cartridge fork kits are NIX as are most of their racing units), and per their convention right is for rebound and left is compression. In compression, fluid flows up through the compression spring stack on the left leg and up through a bypass valve on the right leg. On rebound, fluid flows down through the rebound spring stack in the right leg and down through a bypass valve in the left leg. The resistance of the spring stacks is adjusted by actuator rods driven by servos mounted under the fork caps in accordance with the desired damping level set by the handlebar switches and displayed on the instrument panel. Fork travel is 170mm (6.7 in)

Fork preload is adjustable over a 15mm range by turning the blue hex nuts at the top of the forks. One turn equals 1mm of preload, and to adjust, first disconnect the adjuster servo wiring by pulling back the rubber cover over the electrical connector at the top of the fork and using a small screwdriver to depress the connector’s locking tab. It should be obvious upon inspection. The adjusters have no indicator lines as do some bikes; they remain flush with the fork caps and are internally threaded, mating up with externally-threaded “preload tubes” atop the springs. There’s a stop at both minimum and maximum preload. DON’T force the adjusters (they should turn easily) as doing so can distort the preload tube, causing friction on the damping actuator rod that passes through the tube to the valves located deep within the fork tubes. The adjuster servos produce very little torque and can’t overcome any such friction. Because the forks are relatively long travel (for an Ohlins road fork), Matt suggested that 55mm of loaded sag (about 1/3 of the 170mm total travel) is a good starting point for adjustment, vs. the more common Ohlins suggestion of about 30mm.

The longer travel of the DES fork compared to a normal Ohlins R&T unit also means that the standard fork spring has a relatively low rate of 6.0 N/mm (34.26 lb/in), compared to a common rate closer to 10Nm/mm; because there are TWO fork legs, the front spring rate is 12.0 Nm/mm (68.52 lb/in). Optional springs in 7.0, 7.5, 8.0 and 9.0 (and maybe higher) N/mm are available from Ohlins at about US$135 per pair. I’m in the process of calculating what the initial spring compression is with the adjusters backed out completely based upon comparing the bike’s weight with the static sag, but I’m not there yet – stay tuned! Matt said that the actuator rods are popped off the servos to change the springs, and snapped back in upon reassembly. He cautioned that dropping them into the fork will require a front end disassembly to retrieve them, and that care should be taken to not bend them while they’re out lest they bear against the preload tubes and overpower the servos. It would seem that one could remove the fork cap, servo and actuator rod as a unit after disconnecting the wiring, but perhaps this raises the risk of bending the actuator rod while it’s out of the fork since it could not then be laid flat. Not having actually done this I can’t speak with authority, and I didn’t think to question him about this.

Fluid level in the forks is not so critical that if must be reset if the springs are changed; only reasonable effort is required to drain the old springs of fluid. Any fluid that remains on the old springs will have negligible impact on the proper operation of the fork. The fluid itself is critical, not as to its viscosity but as to its composition. Ohlins strongly recommends that only Ohlins fluid be used for its particular lubricating qualities which they claim greatly reduce stiction. As to viscosity, Ohlins forks all use the same fluid, as compression and rebound damping adjusters obviate the need to change viscosity to alter damping.

Shock
The DES shock is an Ohlins TTX unit, which stands for “twin tube”, er, “X”, I guess). The shock piston is a solid unit, with the spring stacks contained in the head of the unit. On compression, the piston (which is solidly mounted to the shock shaft) rises in the inner tube pushing the fluid above it through the compression stack, after which it circulates down through the outer tube to fill the void left by the rising piston. On rebound, the descending piston pushes the fluid down and out of the inner tube and into the outer tube, where it flows up to the rebound stack and then into the inner tube to fill the void left by the descending piston. Because the fluid flows in a continuous circuit, the remote reservoir requires only about 1/3 of the pressurization of a single tube shock, whose reservoir pressure must be high enough to prevent cavitation downstream of the spring stacks. Shock stroke is unknown by me as of yet, but I’m working on it!

As with the forks, the resistance of the spring stacks is adjusted by servos in the shock body in accordance with the desired damping level set by the handlebar switches and displayed on the instrument panel. Unlike the forks, because both spring stacks are in the shock body it would appear that the servos act directly upon them without the need for long actuator rods.

Shock spring preload is adjusted by another servo on the shock body which, I presume, is geared to a threaded adjuster on the upper spring perch. Again, adjustment is in controlled by handlebar switches and displayed on the instrument panel.

The standard shock spring rate is 85 N/mm (much stiffer than the fork springs because: a) there is only one spring; b) there’s more weight on the rear of the bike (approximately 45% front, 55% rear with rider, by my calculations); and c) the swingarm has a certain leverage ratio, meaning that one inch of wheel travel moves the shock only some fraction of an inch. More weight divided by less travel equals a higher spring rate. Since many Ohlins shocks seem to have a stroke length of about 55mm, I’m guessing that the ratio is at least 3:1 (calculation in process; stay tuned for this as well). An optional spring of 100 N/mm is available from Ohlins for about US$90.

The DES shock does not have a ride-height (overall length) adjustment as is common on other Ohlins shocks. Those shocks typically have a threaded coupling where the piston rod meets the lower shock mount which can vary the length of the shock itself independent of preload adjustment. Oh well, I guess we can’t have everything! Matt suggested that 55mm of loaded sag was also a good starting point for rear preload adjustment.

Miscellaneous
Matt had just returned from Laguna Seca, and I suggested that Ohlins must be pretty chuffed with Yamaha’s 1st and 3rd in MotoGP and 1st and 2nd in AMA Superbike. He informed me that Kenth Ohlins had bought the company back from Yamaha two years ago. Good on yer, Kenth!