Ducati OEM Fork/Shock Spring Rates (Rear shock info merged in)

[Javamoose]

So, it seems like a lot of us like to switch out the rear shock on our monsters.  Popular choices seem to be superbike rear shocks with new springs, etc.

What I would like is for us to use our collective smarts on if there are other shocks out there that would be a good upgrade compared to those of us with basic rear shocks and beer budgets.  Sure, we would all love to have the case to order brand new Ohlins or Matris rear shocks, but let's be honest, who has a spare $1,800 - $2,500 to shell out for something like that.

One thing I noticed poking around eBay was there are a TON of rear shocks for KTM motorcycles that look like they could work.  I also saw this BMW R1200 shock.  The KTM ones seem to be super affordable (and I dig the white spring), but I have no idea if length, weight etc would be appropriate.

So, let's use our collective wisdom and see what we can come up with.  What information do we need to start?  Stock length?  Stroke?  Mounting?

[He Man]

theres lots of ohlins from other Ducatis that will bolt right in. 999, S4Rs are all candidates. Ive seen ohlins go for as low as 350.

Matris shocks are only $800 brand new on close out. Penskes are really well priced and i hear they work great. You dont need to spend $2500 bucks on a shock to get even close to better than u need perofrmance.

[Raux]

A chart of all the stock monster spring rates would be a great start.
I would think the Ohlins single rate spring would be what to go off of. I know the new monster stock sachs have a progressive spring so no way to get a single rate for that.

So...
If someone would fill in this chart

600-
620-
695-
696-170mm spring at 130N/mm 
750-
S2R 800-
900-
S2R 1000-
1100-170mm spring at 130N/mm 
S4-
S4RS-
S4Rt-

[Raux]

after that i suppose measuring the length of the shocks would be key

[suzyj]

695 oem spring is progressive, so no use quoting a number.  It's too bloody soft, at any rate.

I can say the 695 shock is 305mm eyelet to eyelet off the bike, same as a 999 shock.  The 999 shock is a suitable replacement, after you toss the crankcase breather reservoir in the bin and find a new home for the vertical cylinder coil.  Standard prescription for a rider of 80-85kg on the 695 is a 998 or 999 Showa shock, with Ohlins 01091-31 spring (9.68kg/mm, 160mm length).

[Ducatl]

I think all monsters have had progressive springs?

What about other domestic manufacturers that make gas charged units? Somebody like Afco might be able to make a budget-minded coil that could be tailored to each rider.



Traxxion dynamics also sells a penske unit based on the 8900 series set up for the rider but minus the adjusters and it's also significantly cheaper.

[DarkStaR]

What are the various Ducati OEM fork and shock spring rates?

In particular, I'm looking for S4 and S4R spring rates.

I've looked at various charts online, and....

www.ducatimonsterclub.it

Monster:
400:          F: ? - R: ?
600:          F: ? - R: ?
620:          F: ? - R: ?
695:          F: ? - R: ?
696:          F: ? - R: ?
750:          F: ? - R: ?
796:          F: ? - R: ?
800:          F: ? - R: ? 
S2R800:     F: ? - R: ?
900:          F: 0.6/0.8 kg/mm - R: ?
1000:        F: 0.6/0.8 kg/mm - R: ?
S2R1000:   F: 0.6/0.8 kg/mm - R: ?
1100:        F: ? - R: ?
1100s:       F: ? - R: ?
S4:           F: 0.85 kg/mm - R: ?
S4R:         F: 0.85 kg/mm - R: ?
S4Rt:        F: 0.85 kg/mm - R: ?
S4Rs:        F: 0.85 kg/mm - R: ?

Super Bike:

Super Sport:

Sport Classic:

TIA

[suzyj]

Oy!  You forgot the 695.  Which has hopelessly soft progressive springs for both shock and forks.

[DarkStaR]

Oy!  You forgot the 695.  Which has hopelessly soft progressive springs for both shock and forks.

fixed.

[Armor]

My Ducati dealer has seen springs with different spring rates come from the factory.  All bikes are not the same.

[Speeddog]

Forks

What I know for sure:

S4, S4R - linear/straight rate 0.85 kg/mm
S2R1k - dual rate 0.6/0.8 kg/mm - crossover on the rates occurs at about 1/2 travel.

What I suspect, but have nearly no data to support:

S4Rt, S4Rs - Same as S4, S4R - 0.85 kg/mm
600, 620, 695, 800, S2R800, 900 - Same as S2R1k - 0.6/0.8 kg/mm

No idea what the 696, 796, 1100 have.

Shocks

All Monsters (except those equipped with Ohlins from the factory) have progressive springs.
That would be 600, 620, 695, 800, S2R800, 900, S2R1k, S4, S4R, S4Rt.
Seem to be decent if you're under 140 lb, serviceable if you're under 160 lb or so, really not very good if you're over that.

No firm idea what the 696, 796, 1100 have, but IIRC from pictures, they're progressive as well.

[DarkStaR]

Thanks Speeddog! 

[Speeddog]

Update...

Supported by Ducati parts catalogues, and to some extent by parts I've seen:

Forks

All Monsters '02-'07 800 and smaller use the same front spring, a 34720041A.
Fork internals change, at least in the zone '04 to '05, possibly later too.

All Monsters '02-'07 Air Cooled 900 and larger use the same front spring, a 36610381A, AFAIK no big changes in internal configuration.

All Desmoquattro Monsters use the same front spring, a 34710141A, internal configuration same as '02-'07 Air Cooled 900 and larger, but valving different.

So 3 different kinds of fork springs, the dual-rate 34720041A and 36610381A, and the linear 34710141A, 2 different configuration forks (adjustable and ... not)

Currently lacking complete info on Testastretta Monsters, so I'll hold off for now.

Shocks

Everything '02-'07 air cooled used the same shock, so by default, same spring.

'01-'02 S4 has 36520401A shock, but AFAIK same spring as '02-'07 air cooled.

'05-'06 S4R has 36520521A shock, but AFAIK same spring as '02-'07 air cooled.

Currently lacking complete info on Testastretta Monsters, so I'll hold off for now.

[DarkStaR]

So...

<800 2V = 34720041A = ?
900 - 1k = 36610381A = F: 0.6/0.8 kg/mm
DQ 4V    = 34710141A = F: 0.85 kg/mm

Thanks.

[Speeddog]

So...

<800 2V = 34720041A = F: 0.6/0.8 kg/mm I *think*
900 - 1k = 36610381A = F: 0.6/0.8 kg/mm
DQ 4V    = 34710141A = F: 0.85 kg/mm

Thanks.

Edited.

My 0.6/0.8 measurement wasn't the most accurate.
The 0.85 is from a pretty accurate direct measurement and a reasonably accurate calculation.