Ohlins Nix30 2014 R Forks

After a few tries, I ended up with this shim configuration. It provides firm but comfortable sportsbike suspension performance.

Front NIX30 left fork compression stack
8/26/0.10
8/24/0.15
8/10/0.15 crossover
8/22/0.10
8/20/0.15
8/18/0.15
8/16/0.15
8/14/0.15
8/12/0.15
8/10/1.3 clamp (Ohlins 18037-01)

Rear TTX36 compression stack
6/20/0.10
6/18/0.10
6/8/0.20 crossover
6/16/0.10
6/14/0.10
6/12/0.10
6/10/0.10
6/7/1.5 clamp (Ohlins 01449-04)

I think this should improve any Speed Triple R or RS with Ohlins NIX30 forks and TTX36 shock, at least for road use.

You could pay a suspension specialist to install these specific stacks, rather than a vague “make it much softer at both ends”, as I did originally. Neither I nor the specialist could know just what was needed to make it satisfactory for me. As it turned out, the changes necessary in my shock were much more extensive than I expected.

I would also specify new oil in both forks and new fluid in the shock if the bike has done more than about 10000km. Also, a new o-ring for the shock’s compression valve.
I’m not equipped to refill the shock, but at 48000km my shock fluid looks a bit old, and the fork oil certainly did.

I set the damping and preload at both ends at Triumph’s default values for road use, except the shock’s low-speed compression damping, at 8 clicks out, since the low-speed part of the stack is much more compliant now.

If there is any interest, I can detail how I did the work myself for a few hundred dollars.
IanB

 

Hi Ian,

I have a 2018 Speed RS too, and was looking at changing the (too hard) suspension when I bumped into the elaborate description of your efforts. The results sound exactly like what I'm looking for.

Bought the parts for dismantling the fork (at GB motorcycle products), and have taken the compression fork apart. My original FL9280 compression fork shims are exactly as listed in your article. Next step is to get the required new shims and some oil.

Could you share what tools you used for the shim upgrade of the TR9110 shock? And which nitrogen kit you bought off ebay? And what oil make & type did you use? I've seen that "5" is not really comparable for e.g. Silkolene, Motul, Ohlins.

kind regards,
Alex Schoots

 

Hi Alex,
Re the oil, lolachampcar recommends Mobil 1 ATF, the (LV) low viscosity version. I cannot get that in Australia, although there is an alternative here. I happened to have 3 litres of Silkolene from a previous suspension modification in a Daytona 955i 12 years ago. It was nominally 5 weight, but you need to check the Centistokes @ 40 degrees C viscosity spec for the oil. Ohlins 5 weight oil is 19, the LV ATF is 34, Silkolene 5 weight is 24, good enough. I'd use a quality fork oil with a number around there.

For the shock I bought a needle valve exactly like this on Ebay.au.
https://ebay.us/m/ky348s
Beware with this one though. The threaded “nut” that secures the needle bottoms on its thread before the needle seals on the spigot. I inserted a small rubber grommet between the nut and the needle base to apply force on the needle base against the spigot. That worked fine. I discovered this while using the tool to depressurise the shock before I removed the compression valve the first time. I thought there had been no pressure in the shock, the gauge showed zero, but the pressure had leaked away, explaining the brief hiss I heard. You could use a small nut or similar instead of a grommet, or buy a different needle tool. You should see pressure on the gauge before you press in the Schrader valve core to release the pressure. BTW, it may take some force to insert the needle into the shock remote reservoir. This seems to be normal. I lube the needle with a silicon based grease each time.

GENERAL CAUTION: You must ensure the shock is completely depressurised before loosening the compression valve. Otherwise you’ll lose shock fluid, and displace the piston that separates nitrogen from shock fluid in the remote reservoir. You’ll then need a suspension specialist equipped to position the piston and vacuum refill the shock. Support the shock securely with the valves uppermost while the compression valve is out, to avoid spillage and air entering the shock.

RECOMMENDATION: Replace the 22mm x 2mm o-ring on the compression valve while you have it out. It’s easy to damage. Also have some shock fluid (not fork oil) handy to top up the level to the top of the thread before reinstalling the modified compression valve. It will overflow as you screw in the valve and prevent air bubbles.

For the nitrogen, I bought this kit in Australia. It’s a disposable food-grade cylinder, with gauges, a hose, and a schrader fill nozzle.
https://ebay.us/m/XNw6gq
You can buy these components separately, but you need to ensure it’s a double gauge regulator for disposable bottles, not any normal size gas regulator fitting. The kit is simpler. This regulator controls the shock pressure, the gauge on the needle valve only measures it. The kg/cm2 gauge scale effectively reads atmospheres, or bars, since 1kg/cm2 (or 10 tonnes per sq metre) is very close to atmospheric pressure. The twin tube shocks are not very critical of pressure. Six to ten bars is OK, enough to prevent cavitation. I set the regulator to 10kg/cm2, and the needle valve gauge stabilises at about 9 before I withdraw the needle from the shock.

I bought an Ohlins 1860-01 tool to remove/insert the compression valve. It was hard to get, I have not seen another online.


You need to remove the compression adjustment knob using a philips screwdriver, carefully. Ensure the screwdriver tip engages the screw head securely, not too big or small, you do not want to damage that screw. If it's very tight you may need to restrain the knob. I used a hose clamp around the knob with a layer of tape under it. Remove the two detent balls and springs. Then the 5mm holes are available for the pin tool. When reassembling I use some grease to hold the balls in place while installing the adjustment knob.

Instead of the Ohlins tool, you could use a pin wrench, with 5mm pins. I torque the valve to 10Nm (1kg metre), but it’s not critical. With a pin wrench I’d use a spring balance. For example, if I place the hook of the spring balance on the wrench 150mm from the centre of the valve, to get 10Nm I’d need to apply 1000/150 or 6.7kg. I’ve been using a spring balance as a torque wrench forever on motorcycles.

Removing the 6mm circlip that retains the shims on the valve body can be difficult. I initially used 2 stout paper clips and 2 pairs of pliers. Reinstalling the clip is a hassle too. For my third go at the shock’s shim stack I bought a pair of Knipex 4611A0 external circlip pliers, with 0.9mm pins for circlips 3-10mm. Expensive, but anything with 1.2mm or larger pins won’t work. If it’s not specified, you won’t know.

Of course, you need some way of supporting the motorcycle while you remove the rear shock. I have an ABBA stand that supports the bike by its swingarm pivot bolt at each side, so I can remove the shock and swingarm from a bike without a centre stand. On the Daytona 955i I used a 4 foot length of 1" steel water pipe through the rear of the bike somewhere, supported on 2 milk crates each side with 90mm x 45mm wood spacers. Whatever works.

I hope this helps.
IanB

 

Hi Ian,

Thanks for another extensive and detailed description. With respect to the oil to be used I took some time to dig up the datasheets of a range of oils.

As the shim damping operation is related more to the dynamic viscosity than the kinematic viscosity I've calculated the mPa.s in addition to the specified mm2/s.

• Mobil 1 ATF LV HP = Kin visc @ 40°C = 27 mm2/s, density 835 kg/m3 @ 15°C; 22.5 mPa.s
• Silkolene RSF 5 = Kin visc @ 40°C = 24.1 mm2/s, density 851 kg/m3 @ 15°C; 20.5 mPa.s
• Silkolene RSF 2.5 = Kin visc @ 40°C = 13.6 mm2/s, density 819 kg/m3 @ 15°C; 11.1 mPa.s
• Ohlins R&T (01309) = Kin visc @ 40°C = 20.0 mm2/s, density 854 kg/m3 @ 15°C; 17.1 mPa.s
• Ohlins # 5 = Kin visc @ 40°C = 20.0 mm2/s, density 840 kg/m3 @ 15°C; 16.8 mPa.s
• K-tech HPSF-017 = Kin visc @ 40°C = 17.5 mm2/s, density ca 850 kg/m3 @ 15°C; 14.9 mPa.s
• Motul # 5 = Kin visc @ 40°C = 18.0 mm2/s, density 834 kg/m3 @ 20°C; 15 mPa.s
• Motul # 7.5 = Kin visc @ 40°C = 24.7 mm2/s, density 837 kg/m3 @ 20°C; 20.7 mPa.s
• Putoline GP 5W = Kin visc @ 40°C = 23.4 mm2/s, density 898 kg/m3 @ 15°C; 21.0 mPa.s
• Putoline HPX R 5 = Kin visc @ 40°C = 21.7 mm2/s, density 855 kg/m3 @ 15°C; 18.6 mPa.s

You've used the Silkolene 5 which is 20.5 mPa.s, I have opted for the Motul 7.5 which is 20.7 mPa.s and available here in the Netherlands. Other -very- close alternatives are the Mobil 1 ATF (22.5 mPa.s), Putoline GP5 (21 mPa.s) or HPX R 5 (18.6 mPa.s).

cheers, Alex

 

Hi Ian,

Thanks for your help / advice. I was under the impression that the shock would need to be dis-assembled completely for a change of the shims stack. I now realise that it 'only' requires relieving the nitrogen and carefully removing the compression adjuster for access to the shim stack. I will certainly do this myself now I know this.
The shock is already out of the bike, I have a couple of supports that slide on the (fixed / non-foldable) footrests of my rearset.
All I need now is the needle kit (found it on Amazon NL), a pin wrench and suitable circlip pliers.

Why is nitrogen used BTW? If the purpose is to prevent cavitation (boiling) of the oil, the pressure is important, I would say air should work just as well as nitrogen.

cheers, Alex

 

Hi Alex,
Back in 2013 with the Daytona's Showa rear shock I did use air, because I had a foot pump that would go to 200psi. It worked fine. As with tyre retailers here in Australia trying to get you to fill your tyres with nitrogen, any advantage is small. Nitrogen, like any gas, or mixture of gases, obeys the gas law PV=nRT. Air may contain water vapour which could condense out. It also contains oxygen, in the same periodic table group as sulphur, so can have a similar effect on natural rubber and vulcanise it slightly, making it harden. N2 has a similar molecular size to oxygen, so leaks at about the same rate as air (contrary to what the tyre people say), which is about 78% N2, 21% O2, .
Nitrogen (in the form of N2 gas) is cheap, and relatively inert chemically because of its strong triple covalent bond. I'd be happy to use CO2 in a shock, and the small canisters I carry to inflate a flat tyre are CO2 as well.

Yes, modifying the compression stack in an Ohlins twin tube shock is quite simple, otherwise I'd pay a specialist to do it. The advantage is being able to specify exactly what shim stack you want. In another forum I saw that a specialist here in AU had changed the piston in a TTX36 shock from a plain one to one with a compression shim stack, to allow greater oil flow (through both piston and valve) for high speed suspension travel. It was probably very expensive to do that, and in my view, unnecessary.

BTW, unlike the shims in the fork, which are 8mm ID, the shims in the shock are 6mm ID. Four years ago I had a specialist reduce the damplng in my shock. He did it by reducing the clamp shim diameter from 10mm (Ohlins 01449-03) to 7mm (Ohlins 01449-04). This is actually a 6mm ID shim, 8mm OD, with a 7mm diameter lip. Otherwise, a 7mm clamp would be only 0.5mm thick from ID to OD. This part number 01449-04 does not seem to be very available, so you may need to order the 8mm OD clamp 01449-01. It should not make too much difference. The significant change is the thinner shim stack, only 30% as stiff as the original.
IanB