M1100S rear shock spring preset length

[dennisd]

My Ohlins DU7380 FINALLY came in today.

Before I tear into things I'd like a favor from someone with a M1100S.  Measure the stock adjusted length of the spring; the way it came from the factory.  I want the actual compressed spring length, do not include the adjustment rings or the collar at the other end; only the spring itself.  This will give me a good starting point before I adjust the actual sag.  I weigh 175 and I think that is what the bike is set up for stock.  This way I won't be starting out in the dark.

[dennisd]

Common guys, somebody's bound to be able to help me out here.  I know I can do it from scratch, it would just be so much easier knowing a starting point.

[ungeheuer]

Not sure I've quite understood what you're after here.... But... the rear spring on my M1100s at its current adjustment for the 80kg me, measures 165mm - nobody on board.

That help, or did I miss something??

[dennisd]

Sorry, I guess my description of what I am wanting to know is kind of confusing.  What I want to know is, what the installed spring length is, the way it came from Ducati with the shock fully extended, no load at all on the rear wheel (the same as it would be if the shock was not installed in the bike); in other words spring pre-load.

Your info should help me though since I'm the same weight.  Did you have to adjust that from the way it came from Ducati?

[BK_856er]

I think you are asking about spring preload.

It might be different for progressive springs that you generally find in OE applications, but for an Ohlins linear spring a good number is about 15mm.  That's the difference between the free length (off shock) and installed length (on shock, off bike or bike unweighted).

Whatever the number was from the M100S is not really relevant anymore.  I don't think you want to try and match the preload unless you are reinstalling the exact same spring.

A proper weight linear spring will have a preload around 15mm and appropriate free sag and rider sag for your weight and tastes.

It's a good idea to check rear unweighted ride height before and after the shock change to confirm that it is unchanged.

Hope that helps.

BK

[Raux]

the 1100s has the single rate ohlins spring on it, that's why he was asking for that i think.

[dennisd]

Sorry I was a little confusing with the wording on my question.

The info I needed is in my shop manual under (insert drum roll here) "Setting the rear suspension" 

Now I just need the free time to get it installed.

[dennisd]

For the record, the 1100S spring preload is 19mm giving a standard length of the preloaded spring with the rear wheel raised off the ground (this is what I wanted in my original question, just didn't word it right) of 150mm +/- 1 mm.

[BK_856er]

For the record, the 1100S spring preload is 19mm giving a standard length of the preloaded spring with the rear wheel raised off the ground (this is what I wanted in my original question, just didn't word it right) of 150mm +/- 1 mm.

What is the OE spring rate that goes along with that factory installed length specification?

(just asking for the sake of completeness)

BK