fork rebuilding

The older V4 Ohlins (non gas charged) forks called for 230mm air gap without spring and preload tube. Should be the same forks. I had a 1199S shop manual but don’t remember where I have it stored. The air gap is listed separately in the manual from the procedure on how to rebuild them cause Ducati.

Found it. In the 1199S shop manual they list the fluid volume, not air gap.

Thanks guys, great info! I doubt my Ducati ever had the forks serviced in its lifetime, so this oil is probably 11 years old if not more. But the bike only has 6000 miles on it. I’ve only owned it about a year and a half. It sat parked much of its life- :-(

So just measure 155cc fluid then and add, per leg. Why do I see all the guys in the videos sucking out excess fluid above a certain line? Like 150mm down from top? I think there’s a correct air gap spec to go along with the fluid volume spec- anybody know what it is?

By the way, I’m using Liqui Moly motorbike fork oil, 10W medium.

SuperDomestique said:

The 23 V4R service manual that’s been circulating mentions measuring WITHOUT the spring and preload tube.

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I can't read güd

Take this with a grain of salt, I hung out with Dan Kyle as he overhauled a set of forks a couple years ago and this is what I remember him doing except he didn't wait for things to drain since he opened the cartridges. Do this on your known good fork. These are steps I would take:

1. Disassemble fork top cap/preload assembly
2. Measure and record with welding wire the distance of top of oil to top of fork tube uncompressed.
3. Remove spring and repeat measurement with fork compressed
4. Fully empty fork and cartridge into pan and measure the volume with a graduated cylinder. Cycle fork repeatedly and let hang upside down overnight
5. Clean everything and do your overhaul with new seals and bushings
6. Reassemble everything up until spring installation
7. Add 250-300 ml (or 50 ml plus what you measured in Step 4) fork oil and cycle fork/cartridge (you'll hear squishy sounds in the cartridge until it's fully bled)
8. Use your fluid level syringe set it at the height you got in Step 3. Aspirate out remaining oil
9. Install spring and repeat measurement in Step 2
10. Install top cap/preload





Also check out this thread When to change fork fluid?

greggiacona said:

By the way, I’m using Liqui Moly motorbike fork oil, 10W medium.

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I would recommend against using anything other than Ohlins R&T 43 or Shell Donax TA. Dan Kyle stressed only use Ohlins fork oil in Ohlins forks

SuperDomestique--I really appreciate your feedback in this thread! Great info--I'll have it nearby as I proceed.

Your graphic included in the last post is from the R1M service manual--I've got that same PDF saved and the fork pages printed. I can't use those exact same R1M fluid volume specs because the R1M uses a different Ohlins electronic fork that the 1199S, yes?

The other poster above showed 155ml fluid in the 1199S service manual--The R1M shop manual indicates 263ml. So--I can't really use the R1M service manual as an accurate guide, right? Even so, the construction of both Ohlins forks seem very similar---

By the way---am I draining oil not only from the lower fork leg, but also the internal cartridge? The R1M manual indicates the cartridge cannot be drained--?

I've not yet seen the inside of my forks so it's still somewhat of a mystery what's inside. I do have the fork in the vise and top cap loosened. I plan to disassemble and

drain tomorrow AM-

Also--

I found a nice vendor on Etsy who makes custom fork clamps for use in a vise. Here's his contact info at Etsy:


Nate is the owner--good guy--he contacted me personally to confirm my fork sizes.

Greg

SuperDomestique said:

I would recommend against using anything other than Ohlins R&T 43 or Shell Donax TA. Dan Kyle stressed only use Ohlins fork oil in Ohlins forks

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I knew somebody would mention this. Too late--it's ready to go, in the garage--will be fine--Liqui Moly is a fine brand--I'm not concerned! It's metal and fluid---Ohlins metal is not seriously different that another manufacturer's metal.

greggiacona said:

I knew somebody would mention this. Too late--it's ready to go, in the garage--will be fine--Liqui Moly is a fine brand--I'm not concerned! It's metal and fluid---Ohlins metal is not seriously different that another manufacturer's metal.

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It’s the viscosity that I’d be worried about if the cartridge is open. The valving is specific to the viscosity is what I was told.

But I’m not sure if the oil in the fork lowers is the same as the cartridge. I’m 60% sure it’s an open bath cartridge. I don’t remember him adding oil to the cartridge and then to the lowers. Maybe the NPX has a closed cartridge due to the nitrogen pressurization?

The 155 cc reference to oil level could be actually millimeters like in the R1 manual Step 9 diagram (a). That’s why I’d be measuring oil level as I disassemble and reassemble. Don’t be surprised if the oil volume that you drain isn’t 155 cc (=ml)

The bushings in ohlins forks are glued in with red loctite. They are coated so if you're not seeing brass leave them alone (I got 40K street miles out of a set). If you see brass then you can heat them up with a heatgun and wait until you see the white smoke. Then you can knock them out with an appropriately size socket or whatever else you got thats the right size. On the earlier manual forks the cartridges are also loctited so you have to heat them also to change the shimstack. You should be able to pump out the cartridges but if not leave the caps off and turn the forks upside down for a couple of days. And as has been said use the right ohlins fork oil. The true viscosity relative to other oils will be different. So typically an ohlins 5 wt has greater flow characteristics relative to other 5 wts. Ohlins will have a oil height vs air spring graph for that fork to help you choose oil height relative to your use.

SD--got it, thank you for that-I do agree that the 155cc probably is a mistake--I think it means 155mm from the top for air gap.

All the videos I've seen have guys adding 500ml of fluid to the fork without a spring I think-- and then they're measuring 150-155mm from the top and sucking excess out, once spring is installed. I need to verify this--anybody?

My concern is---how expert are these Youtube dudes--maybe they're doing it incorrectly? that's why I'm seeking OEM specs/values/measurements.

baggerman---so, your message is to not worry about the oil in the sealed cartridge, just dump and replace the oil in the lower fork, yes?

I really appreciate all those who assist on these forums.
I'm jumping into this deeper tomorrow AM-
Greg

The oil in the cartridge is not sealed in. Back the damping needles out and turn the fork upside down. The cartridges will empty after a spell. You're draining the cartridge thru the low speed damping orifices (orifii?). Same thing when you fill it. It will take the cartridge awhile to fill. The manual ones I pump full. I haven't serviced a set of these forks but 460-500 cc is typical for most ohlins. Use their oil. It really is better. If you've not lived with Ohlins before get used to changing seals. Keep the tubes clean, make sure the fender fully protects the lower leg. Use the lastest revision seals. The Ohlins are a bit of a PIA but they simply work better IMHO. As superD said Dan Kyle is a good guy.

Unfortunately Dan died a year or so ago. Super nice guy. He showed me around his shop and he has an amazing motorcycle and bicycle collection (cars too).

Honda or SKF seals seem to be better quality that the Ohlins ones if I remember correctly. This is what I’d use instead of the Ohlins ones

SuperDomestique said:

I would recommend against using anything other than Ohlins R&T 43 or Shell Donax TA. Dan Kyle stressed only use Ohlins fork oil in Ohlins forks

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Do you know what the OEM fluid is? Then again, I can't readily find Shell Donax TA.



An old post from 2021...

Shazaam! said:

There’s confusing information in the Manuals regarding what hydraulic fluid should be used in Ducati forks.

Shell Donax TA should only be used in Showa forks.

Shell Advance Fork 7.5 should only be used in Ohlins forks.


The Ducati Owners Manuals and Workshop Manuals fail to make this distinction. They suggest that these two fork oils offer equivalent damping properties. They don’t. They have significantly different viscosities.

Here are the fork manufacturers specified products for Ducati forks:


Showa — Suspension Fluid SS-08 (10 Wt): Measured 36.5 cSt @40C

(Pro Honda SS-8 (10 Wt) Fork Oil is the same fluid)



Ohlins — Front Fork Fluid 1309 (9 Wt): Measured 19.0 cSt @40C


Compare Viscosities:

Shell Donax TA: Measured 34.9 cSt @40C

Shell Advance Fork 7.5: Measured 22.0 cSt @40C


Ducati has over the year) changed the recommended fluid for Ohlins and Showa forks. AGIP was specified before Shell — of course, AGIP was the sponsor for Ducati racing activities before Shell took over — so it's no surprise to see only Shell Products recommended in the Owners and Workshop Manuals.

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All-excellent info thank u-
Greg

bp_SFV4 said:

Do you know what the OEM fluid is? Then again, I can't readily find Shell Donax TA.

Ohlins Front Fork Fluid #5 1 Liter 01330-01

HHR Performance presents the Ohlins Front Fork Fluid #5 1 Liter 01330-01 01330-01 and other parts you need available through hhrperformance.com, Sandpoint, ID

hhrperformance.com

View attachment 52649
An old post from 2021...

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I saw this. But if it were me I’d use Ohlins R&T

I saw a couple of listings on seller's websites which says Ohlins R&T oil is only for their R&T products.

I'd have to dig through my emails, but I think Dave Moss said to use 5wt oil in my forks when I asked. In the early Panigale V4 models he advocated going to heavier oil, which is why I asked.

Ohlins #5 oil is 7.5wt, which is a ridiculous shameful product naming scheme problem. The Swedish seem just as ...... as the Italians as coming up with useful names for products.

I also barely recall watching a Dave Moss video where he speaks to centistokes measuring scheme. R&T has a different, but the significance of which is unknown, different centistokes value despite being having the same 7.5wt value as compared to Ohlins #5.

This is perhaps the best Ohlins fork service guide video I've found, even though it's off an Aprilia RSV4:

SuperDomestique said:

Unfortunately Dan died a year or so ago. Super nice guy. He showed me around his shop and he has an amazing motorcycle and bicycle collection (cars too).

Honda or SKF seals seem to be better quality that the Ohlins ones if I remember correctly. This is what I’d use instead of the Ohlins ones

FORK SEAL KIT (OIL & DUST), OHLINS 43 MM, GREEN - InnTeck USA

OIL SEAL DIMENSIONS: 43 x 55.1 x 9 mm DIRT-SCRAPER DIMENSIONS: 43 x 55.55 x 5 mm SKF seals have been designed and manufactured to obtain better performance than with traditional ones and consequent increase of: Durability Performance and smoothness (as per video below) Fork’s protection from...

innteck-usa.com

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I did not know he died. I seem to remember talking to him last year when I bought my TTX. Must have been the year before. Bummer. Good guy.

Turns out when I put my fork spring compressor on the cartridge like the one in the video above and draw down the spring, it does not release the upper cap. The lower silver bracket should separate from the upper cylindrical cap but it’s not.

I’ve compressed the spring all the way down to top of the gold outer tube. It brings the entire upper assembly with it:-(

I do see a slight separation at the seam so I know they are indeed not connected.

If I were able to draw the spring down more, perhaps it may pull that silver lower retaining cap down, but I’m out of room because I’m at the top of the outer tube.

So- can I just put my 19mm wrench on that lower nut and hold the top nut on the cap and break loose? Without compressing the spring?

I may need a specific tool to get to that 19mm lower nut.

Greg