After work blast (see post #5, example of Dave Moss Suspension Settings for one rider - Page 2 - Ducati Supersport 939 Forum
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post #11 of 16 (permalink) Old 04-14-2019, 07:08 PM
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Originally Posted by A8tomic View Post
Thank you so much, @theresanothersteve . I don't know how I missed the preload info in your post originally. Excuse my newbyness, but where do you measure sag?
I'm really excited to try this. I'm about (exactly) 100kg; no Italian jockey!
Google it, or go to the Dave Moss Tuning web site, there are a lot of very good videos showing how it is done. Suspension for mortals is another good resource, available on YouTube.

It's a two or three person job unless you have a motool or other electronic sag tool. You basically need to measure your suspension fully unloaded (extended), under the weight of the bike (free sag) and with the rider. There are a couple of people who suggest compressing the suspension (with rider on) and letting it settle to take a measurement and unloading the suspension (again with rider on) and taking a measurement and then averaging the two to take stiction out of the equation.

The process is similar for the forks and the shock (rear suspension).

It is important to have free sag on the rear. The bike should settle about 10mm (sag is best measured using the metric system, it makes the mathematics mush simpler) under its own weight. It should sink a further 25 to 35 mm under rider weight. If you can't get those figures you will need to consider a new rear spring.

With the front suspension you will want about 40 mm total sag. If you weigh the same as me you will be winding the preload all the way in (clockwise) to even get close. And, even though the sag is almost right, the front still bottoms out. Now I've gone for a stiffer spring I can get the right sag, the adjusters are in the middle of the adjustment range, and most of the time I have 25mm of travel left (measured with a zip tie around the fork tube). I can still use up most of the travel (8mm remaining), but that's from demon braking from high speed. If you use most of any suspension adjustment (preload, damping) you should modify the suspension (get a suspension specialist to do it) so you can get the ideal setting with the adjuster about half way through its adjustment range.

As you've probably worked out you are aiming for the bike to use about 1/4 to 1/3 of its suspension travel to support the rider. This leaves 66 to 75% to compress over bumps, while the rider sag will extend into depressions. The aim is for the mass of the bike to remain travelling on a level plane while the wheels follow the road surface. Damping controls the speed the suspension moves, both in reaction to an irregularity but also recovery.
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post #12 of 16 (permalink) Old 04-18-2019, 07:18 PM
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At the risk of pestering you, @theresanothersteve , could you let us know the p/n for the front springs you used for your 100kg self? Also, the settings you provided above were for the old (oe) springs, then you added the 2-3 clicks for the new, right?
I did search for setup vids (and did watch several DMT vids) before asking here, but info for our exact bike and weights is priceless, so thanks again!
-Tom
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post #13 of 16 (permalink) Old 04-19-2019, 12:10 PM Thread Starter
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Thanks Steve, you've taken a lot of the mystery out of it for me. I've got a couple of my kids all weekend so wont get the chance to have a go at adjusting it...or be able to go for a ride, and the weather is expected to be a perfect 20-23c all weekend.

Something to look forward too next week though.
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post #14 of 16 (permalink) Old 04-21-2019, 02:49 AM
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Originally Posted by A8tomic View Post
At the risk of pestering you, @theresanothersteve , could you let us know the p/n for the front springs you used for your 100kg self? Also, the settings you provided above were for the old (oe) springs, then you added the 2-3 clicks for the new, right?
I did search for setup vids (and did watch several DMT vids) before asking here, but info for our exact bike and weights is priceless, so thanks again!
-Tom
Not sure of the part numbers, but I think @grond1234 and @Rhino have posted them elsewhere.

The settings in this post are for the oem springs, just to give you blokes a starting point.

After installing the new springs Dave suggested a complete change in SAG, particularly at the rear and a new set of compression and rebound settings for front and rear.

I'm guessing most people on this forum aren't going to do the job themselves, but get a race shop to fit the springs. They should be able to do a basic setup for you. We can then compare how the settings of listed felt, how the race shop setup feels, and the suggestions Dave made. Note that I made a couple of other small adjustments, after all Dave wasn't here to see the bike and I wanted to go back to the feel it had pre new springs.

UPDATE: Part numbers: here!
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post #15 of 16 (permalink) Old 04-21-2019, 09:42 AM
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Ohlins front Spring part number 04744 -95
The - 95 relates to the Spring weight. The come in 80 , 90 ,95, 10, 10.5 the OEM is an 80
You can mix springs to get the result you want eg a 90 + a 10 = 190 and 95 + 95 =190
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post #16 of 16 (permalink) Old 04-21-2019, 01:49 PM
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Then getting home and parking her up, I've always got to turn back and take a look at her as the metal contracts and ticks...I've had her over three months and still get a kick from thinking "I've got a Ducati". I've said that in a few posts now, but it hasn't worn off at all.
Don’t worry....it gets even better with time.

Pay attention to psyopper’s posts...that guy is full of Ducati model history and he’s a great member of the forum.

Sorry....back to suspension.

So, lemme get this straight.

I twist this little tube, it gets loud, I go forward really fast and it makes me smile...is that how it all works?

Last edited by NothingClever; 04-21-2019 at 01:55 PM.
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