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Discussion Starter #1
Setting up the suspension better for my featherweight butt on the 2013 848 corse special edition.
Let’s call it 145lb nekid weight 155 dressed. Rarely am I in full leathers, usually a summer jacket and jeans.

With the factory rear Ohlins and 1091-24/80 spring backed out I’m at 11mm static and add 8mm (19 total) for rider rear so a long way from where I need to be (front is 25 static and 13 rider 38 total with preload backed off completely however at that is completely mismatched to the rear and I have them 3 turns in presently as closer to 22/12 totalling 34mm. Not right but it’s more predictable presently.
The front seems easy and whilst the factory spring is close I believe a lighter spring will allow better fine tuning. Order a 9.0 spring for the Showa forks and seals and new oil and I should be well inside the ballparks to get what I need at that end.

No way in hell is the 80 rear spring suited to me despite every “table” having it for The 140-160lb range. Not a chance and I’m not going to rush out and machine my nuts down to lessen preload as it’s not even close. I’ve ordered a custom spring 57/160/70nm 7.1kg/mm or 400lb/inch depending on what you like to call it. Let’s call it basically a 1091-18/70 but in red. Bit of a guess as nothing adds up but know I need significantly lighter. It’s been somewhat possible to tame the bucking nature of the rear with dampening but I’m that far off it’s not really safe to get real keen on any corners, the rear is light, both ends tend to skip and it’s a right dog 😆
And yes I know suspension is done to death. Soz to jump in the ring straight up with this but has anyone switched out the rear Ohlins to a 75 or 70nm spring and logged some sag figures for their new and old factory spring against butt weight and preload ring position?
More curiously has anyone gone lighter than a 70?
 

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I have an 848 Evo and weigh about the same as you. The first issue is the progressive link which is designed to handle a passenger. I replaced it with a linear link from Foresaken and am very pleased with it. I then got rid of the stock shock with an Onlins TTX. Much better. The rear no longer feels rock hard and more planted. My advice would be first get a linear link then you can have a better idea what the shock is really doing.
 

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Discussion Starter #3
I have an 848 Evo and weigh about the same as you. The first issue is the progressive link which is designed to handle a passenger. I replaced it with a linear link from Foresaken and am very pleased with it. I then got rid of the stock shock with an Onlins TTX. Much better. The rear no longer feels rock hard and more planted. My advice would be first get a linear link then you can have a better idea what the shock is really doing.
I kind of wanted to keep that as I will be 2up on occasion.
Pulled the pin and ordered. 57/160/70 custom.
I guess I’ll see where that gets me solo and 2up sags and ride qual then go from there. The former being more important. If I can’t get what I want out of it I may look into getting a 57/155 65 or 70 made. But won’t know for a few weeks now and dropping back 2 spring loads and The length in one go isn’t something I want to do. Little too many unknowns.
 

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Discussion Starter #4 (Edited)
Gonna keep adding stuff here so I can find it. Might help someone some day.
Played with sag measurements today with myself and my kids for rider weight (no gear on) as they’re little and fit on the seat with me 🥰

Still factory 24/80 spring backed off to almost foul the shock. 3 thread pitches showing, lets call it 5mm above the nuts remaining.
static sag - 11mm
50kg rider- 19mm
65kg rider - 23mm
85kg rider - 29mm

May be benefit in going a shorter 6” spring (have ordered a 6”/152mm 400lb as well). Probably mod the nuts/shock to get a 5mm reduction in preload out of it. I guess I start with the new spring in the same place to get a baseline and see what changes it made. Should be some fun science in this.
 

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Discussion Starter #5
Pulled the shock off today after machining a couple frame dowels up. Pretty crappy job to do but got there. Can see how badly the tyre is wearing in the pic.
171705
 

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Discussion Starter #6
Max spring length is 140mm when the lock nut hits the shock body. Modifying the lock nut to match shock body taper and removing the mm step in the adjustment nut has me at about 144mm maximum length. May not need the extra 4mm but it’s there now if I do and if it wasn’t such a crappy job removing the shock I’d be tempted to put the factory 80nm back in and see what difference it makes but stuff that. Will wait for the first 70nm at 152mm to arrive.

171706
 

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How is the Tyre wearing badly? I didn’t spot it
 

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Discussion Starter #8
How is the Tyre wearing badly? I didn’t spot it
If you look at the tread grooves you can see a lip on the trailing edge. Indicates inadequate rebound dampening. Orange peel on lean says too firm spring and bouncing around cutting up the tyre. This is just casual weekend rides thus far on this bike for me, ridden harder it would be worse. Dunlop tyres tend to be a harder carcass so show more on the tyre than a softer carcass.
 

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Discussion Starter #9
New eibach spring is in 0600.225.400
Currently set to 18mm of preload. Maths on that being 125kg.

previous factory spring being 20mm of preload and 160kg.

I guess there’s about 10-11mm of preload I can back it out now (6mm preload minimum) compared to factory spring which stopped at 20mm preload.
Roughly measured sag with the help of my 8yo daughter and ballpark at 30mm however waiting on older hands to better check it so don’t hold me to that. Definitely a noticeable difference just pushing the back down now.
Best bit! No more ugly yellow spring 😂
171742
 
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