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Discussion Starter #1
What type Ohlins fork springs do I have to order to fit the stock Ohlins forks on a S4RS ? Does the R&T series spring fit ? Some websites have directed me to them, others don’t have the S4RS listed for fitment. Do they use the same springs as any Superbike forks ?
 

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Discussion Starter #3
Thank You, Belter. Not quite clear . Are you saying the Ohlins fork type is fg3380 ? Are you saying those are Ducati part numbers or Ohlins Part numbers ? Sorry if I’m dense.
 

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the ohlins part/specification number for those forks is fg3380, might have fg338 on the bottoms of them. that is the ohlins variant of the road going forks fitted to lots of things particular in this instance to the monster s4rs. they might, for arguments sake, be "the same fork" as what's in a 999s, but the 999s will have a different number (fg335 in my listing).

things like springs and valving will most likely vary between the spec, and all that is specified in this oem application by ducati, not ohlins. if you bought "the same fork" from ohlins it would have a different spec number (probably an fg7xxx number) and different valving and springs as they generally don't agree with what the oem ask for.

so if you talk to ohlins about it, you call them fg3380 and they know what you're talking about. ducati monster s4rs or the ducati part number - 34023291a or 34023301a - mean nothing to them.

the ohlins spring series used in that fork is given on the spec sheet as 4744-xx, where xx will be 80 or 100 or the like for the rate in n/mm. so if you want to order springs for them from a supplier you want an ohlins 4744 in the particular rate you desire. the following link is simply an example of this.

https://www.omniaracing.net/en/fron...forks-cartridge-nix30-pair-04744-p-20734.html

i hope this has been helpful.
 

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Discussion Starter #5
Very helpful, thank you. I’ve found those springs listed as replacement for Superbike forks and also they are used on the 30 mm replacement cartridges. Strangely, most sellers don’t list them as fitting the S4RS.
 

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Call Fast Bike Industries in Hendersonville NC. They are the Ohlins Sale & Service representatives for US. Here is the website with contact info. Fast Bike Industries Contact. They are very knowledgeable and can order any part from the whole Ohlins catalogue directly from Sweden. They did my 1098 front fork conversion for my S4R with race valving and weight appropriate springs on used 1098 forks I bought on ebay.
 

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Discussion Starter #7
Thanks, haloguy628.
 

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Discussion Starter #8
Can anyone verify the stock fork spring rate for an ‘07 S4RS ? I read that they come with 9.0 in them. If so, I need to wait until I disassemble the legs to see what is in there because that’s what I thought I needed.
 

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Discussion Starter #9
I bought 5w fork oil because the forks have always seemed harsh to me regardless of settings. Does anyone know what they had in them from the factory ? It seems as if I remember reading it was 7 1/2 w.
 

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If you look in the back of the owners manual is sometimes tell you the recommended oil. Sometimes even spring weights.


Sent from my iPhone using Tapatalk Pro
 

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Discussion Starter #12
Thanks , belter. I was almost right.
 

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the cst rating is far more accurate than the manufacturer's weight.
And it also depends on what Ducati puts in them when assembling the bike. The Ohlins that you get from Ducati are not the same as what you would get if you buy directly from Ohlins. Like the manual specifies, anything in the 7.5 range is close enough that most people will never know the difference. Regular old ATF is perfect and one of the most stable hydraulic fluids you can buy.

Think about it. Forks will rarely change temperature from ambient. No matter how hard you ride. Look at what the fluid in an auto trany for a car has to endure.
 

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Discussion Starter #15
I usually use ATF in forks, but I thought it was closer to 10w . I use it because it usually works fine and I’m cheap. I bought 5w because these forks seem extremely harsh regardless of settings. I’ll also change springs if necessary after I find out what’s in there now.
 
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Discussion Starter #16
I’ve disassembled the forks. The springs have no part number on them but each has one groove cut across the end coil, which must be a form of identification since it would serve no purpose other than causing the end coil to break off. Does anyone know what this groove is supposed to mean ? Other than that, the fork oil was very dirty and somewhat green. What color is Ohlins fork oil normally ? The needle valves under the bottom of the oil tubes were covered in black deposits and didn’t want to come out. I calculated the spring rate and though I assumed it was going to be really high my results were 9.0 Nm, very close to the recommendation for my weight, 8.8. I was hoping to find very stiff springs to account for the harsh ride. My Showas on my SS ( GSXR internals) put these things to shame on rough roads.
 

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I don't know which forks you have, but on FGRT forks (1x98s, pani) the oil is almost like water. Clear and very light weight.
 

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1309 is clear.

ohlins do tend to make the oil rather dirty and sludgy at the bottoms.

the forks should have 1309 in them. the forks come from ohlins assembled via brembo to ducati - they don't touch them.
 

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No fork oil is going to stay this way very long.




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Discussion Starter #20
I held the jar of old fork oil up to a light and you can’t even see light through it. Whatever oil it was appears to have been green when fresh, but black now. I’m replacing it with 5w, 85/125. Since it has the correct springs for my weight, maybe this could help the ride a little.
 
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