Öhlins RXF 36 Fork Explained - How does the Ohlins TTX 18 cartridge work
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- Опубліковано 27 лип 2024
- Robbie explains what's unique about the Öhlins RXF 36 Fork TTX 18 air cartridge and how to set it up. He then runs through some setting measurements on the Andreani DS1 Air Spring Dyno and takes a look at the results.
Ohlins has really created an awesome bit of MTB suspension.
The RXF 36 in our shop: bit.ly/rbc_rxf36
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Nice and clear info!
Thanks!
Excellent video and good information. Would be curious how to change the air spring cartridge out to change the travel.
Great suggestion! thanks, if you send me an email I will reply with the details - rbcbikes@gmail.com
Great video. Thanks
Glad you liked it!
Hi, I also have rxf 36.. i didn't use my bike for like 2mos. And now my fork drops its travel. I mean it looks like it looses air on the main chamber. I have tride pumping it up to recomended psi but my fork still seats low on travel. I hope you can help me with this issue. Thanks
Hi Robbie I just bought a bike with an ohlins rfx 36m.2 and I find that if I pump up the main and the ramp up chamber they equal out each other after I let the bike sit for a few days I run 70psi in main and 190psi in ramp up I always fill up the main chamber first and then the ramp up could this be the reason to my issue or doesn’t it really effect it?
Hey mate...I'm having bottom out issues too...I'm 82kg and I've got 10psi in both chambers over the recommended...it's on a 2022 crafty carbon xr ebike
Hi, could you do a video explaining how to change the tune on the negative air chamber, by changing the ‘tokens’?
Hi Gus, thanks for the message. When the Öhlins M2 fork ships to you it will have one token in the negative chamber and should have an additional one in the box. For a better small bump remove the token in the negative chamber (this can increase the progression on the positive side) for a firmer ride and for less push in the midrange, add the additional token. (this will make the small bump harsher) I recommend that for a lighter rider wanting a better feel on the fork (60kgs and below) to remove the token, and for heavier riders 120kgs to add a token. However its good to experiment and see what's best for you. The Öhlins has a great air cartridge platform to work from and you will be able to get the best tune by trying out the different options. For the start I would just work with the standard setting (with the token in) and work with the ramp up chamber to find your sweat spot.
Hi, I have seen a few people looking for info/video on removing the negative air chamber spacer and tools required for the job, I'm playing around with air pressures but it would be good to feel the difference without the spacer Installed, any advice or info would be appreciated. Good videos, keep it up 🤟
I also want to ask a question, can an air damper like this in the video "stuck" inside and reduce the travel of the fork?
Hi Antonis, yes there are a number of issues that can cause this problem. firstly its possible that the oil in the lower legs gets ingested into the negative chamber, this will limit the travel. Öhlins requires that the fork is serviced every 50 hours to ensure that the negative chamber is kept clean and free from lower leg oil. Have the fork serviced by an authorized service center to prevent this. Secondly, if the air is released out of the positive chamber quickly then the air piston will go past the equalizer ports and the negative air will push the fork down in the travel. to fix this, pump the positive chamber and equalize the fork by holding the wheel and pulling the handle bars up to allow the piston to equalize the positive and negative. If the pressure in the negative chamber is too high it will not be possible to repair it like this you will need to open the air cartridge to equalize this.
Hi, is it normal for the rxf evo air´s ramp-up chamber to lose air after every ride? If not, do some parts require replacement?
Hi Risberr, thanks for your message and support of our channel. Its not normal for the ramp-up chamber to lose air. There is a quad lip seal on the ramp up air piston which might need replacement; but first check if the air is not leaking out the valve! Remember that because the air chamber is so small and the pressure in the ramp up chamber is very high, when you put on the shock pump to check the pressure you will automatically lose up to 50psi into the air pump! This will make you think that the ramp-up chamber is leaking air. If you are unsure then take the fork to your nearest Ohlins service centre for a check and seal replacement.
What happens if i use co2 or nitrogen to pressurize the positive and negative chamber
Hello Robbie, i did change the all kit in my rxf 36 but at the end when i start putting air into the rach. And finish. And go to the main camber the psi is equal the rach.. I let the air go a BOTH chambers are empty... Can you help me... What i did wrong
@iceagle58, thanks for your message and support of our channel. So as I understand that air in the ramp up chamber is going directly to the main air chamber. When you did the service did you replace the quad seal on the ramp up chamber piston and have you remembered to refit the ramp up air piston and push it all the way to the top? My recommendation is to remove the air cartridge and check you have fitted the the ramp up piston. If you took off the main air piston when doing the service there is a O-ring under this so when it goes back remember to include this as well as the Loctite to ensure that piston does not come apart. I think that you have left some part out, please check your procedures and try again. Let me know how it goes.
Robbie is there any videos of changing the length of travel via the air tube.
@jexvi, thanks for your message and support of our channel. Changing the travel requires either a complete air cartridge in the travel length you require or the other option is to replace just the positive air chamber in the travel you require. This second option needs a 26mm soft jaw and some additional understanding so my recommendation is to go with the complete cartridge then its possible to easily swap out when you need to. To replace the complete air cartridge you only need a Shimano cassette tool, 14mm socket and 10ml of lower leg oil.
Nice video to watch even though I already knew it. Anyway I've got DH38 fork and I wonder what is maximum psi I can run in ramp up chamber? I couldnt find this information anywhere...
ZX agent, thanks for your message and support of our channel. What is your weight and bike model and what sag do you run? I will confirm once I have the details.
Thanks for your reply. I am riding Propain rage 2019, weight 67kg with eq and like to run about 18-20% sag
Hi ZX Agent, I recommend 210PSI in the ramp up chamber and 95PSI in the positive chamber, remember to first empty the positive chamber then fill up the ramp up chamber and then only pump the positive chamber to the recommended pressure.
For the Max pressure I would not go over 240PSI in the ramp up chamber.
@@RBC_tech Thank you!
New Ohlins user here, heavier than average and I cannot seem to get enough rebound damping. Even with the dial all the way in, it still feels way too "bouncy" and I tend to deflect off stuff. Is there an alternative tuning or shim stack I should be considering?
I’m going through the same problem myself…I think the only way is to run a softer set both on main air and bottom out… I’m guessing tho 😂
@@midlifesendermtb2178 Sooo, I actually ended up getting a custom tune on my Ohlins 38 m.2 fork and I could not be happier! A heavier Rebound and Compression tune allows me to have the dials closer to the middle of the range, which obviously gives me more leeway to tune it to my liking.
It sucks that I had to do that, but after the tune I can say that this is the best fork I have ever ridden! Extremely supportive through the mid stroke and very active feeling throughout the travel. Then, obviously you can use the bottom out chamber to customize the progressivity.
The shop I used was referred to me directly from Ohlins. Happy to share their information if you want...
@@FernFlowMtb thanks for replying mate…. I’ve only had this fork for about a month…I’m in Australia so I’ll have to find someone over here… it’s can be a very confusing fork aswell, especially the bottom out…I think a custom tune could work fit me aswell.. I’m 100 kilo.
Gave you a sub aswell lol
@@FernFlowMtbwho did u use to tune your rxf38?
@@justinstelz3024 I used a place called Revolution Factory Suspension in Arkansas. Would definitely recommend giving Mark a call if you’re in the market
Hello where i can buy the positive chamber,because i have a 140mm and i want a 170mm
Hi Antonis, You have a choice to purchase a complete air cartridge at 140mm or just replace the positive chamber shaft to the 140mm shaft. The 140mm shaft will need to be fitted at your Öhlins service center so contact them to arrange to have this fitted.
Awesome vid. Didn't know the tokens reduced travel on other forks.
Glad it was helpful!
They don't reduce travel. They reduce the amount of travel you use for the same amount of force applied to the fork. Which is the point of using a spacer because you are using too much travel for a situation and bottoming out
@@devinwillis7787 Correct, see my reply to Sean on the same comment.
@@RBC_tech I do not get it. Tokens replaces the air in air spring. The air can be compressible but tokens cannot. In case where there will be no air in air spring (both positive and negative side), piston would hit the tokens stoping fork compression. Without them it will be stop by the end of air chamber. In that way of thinking, travel of fork with and without tokens are not the same. What changes would made adding the air to this theoretical model would does? The air chamber with tokens is shorter. The air chamber with 120mm length and 170mm with 5 x 10mm tokens will need same pressure to close up. But from the out site shorter will be clearly bottoming out where longer would look like redy for more.
@piotrekh7606 Scott uses air very successfully to reduce travel and change the progression curve in their proprietary NUDE shocks. By moving the remote to the middle position, the NUDE shock reduces the amount the shock will compress by 30%, this is achieved by cutting off a portion of the air chamber, effectively adding and removing tokens at the push of a button. All air chambers work on progression when compressed. So if you start with a fork that has no tokens and has 80 psi with a rider of 80kgs the chamber will get full travel, adding 2 tokens with the same 80psi pressure will change the progression curve making it harder to get full travel with the rider on the same course. Adding more tokens make the air ramp up super aggressive so that the 80kg rider will not be able to compress the fork completely due to the increased air ramp up at the end of the stroke. The Ohlins air chamber uses a dynamic ramp up chamber which has its own progression curve that allows for full main chamber compression with good support in the mid stroke and at the end
I cannot get my RXF38 M.1 to stop bottoming out. 205lbs riding weight and I keep having to add air pressure to the ramp up chamber. Ohlins recommends 210psi and I'm currently at 260psi and it's still bottoming out. Any ideas? Any help you can provide is really appreciated. Thanks.
Hi Mike, thanks for your message and support of our channel. Please can you provide me with the following details. What air pressure are you adding in the positive chamber and what bike are you riding, how much travel does the fork have? Please be sure to follow the setup guide, release all the air from the positive chamber first then pump the ramp up chamber before inflation your positive chamber to reach 25% sag (my recommendation for this fork)
@@RBC_tech Thank you for responding! I'm currently at 115psi in the main chamber as anything more makes the fork feel much too harsh and traction seems to suffer. I'm riding a 2021 Commencal Meta Power 29 Ohlins Edition. The fork has 170mm of travel. At 25% sag the fork bottoms out. I started out with Ohlins recommended settings and the fork bottomed out too easily which is why I've had to keep adding pressure to the ramp up chamber. Nothing seems to work. Thoughts? Thank you for your help.
Hi Mike, thanks for the update, ok this is super strange, the only think I can think is the token in the ramp up chamber has been removed. There is a +- 6cm orange air token in the ramp up chamber that controls the progression of this chamber, to check its still there you will need to remove the foot nut and check inside the ramp in chamber if this is there, it will slide out once the foot nut has been removed.
@@mikeoxley9796 Did you sort out the bottoming out issue?
@@jonnywilson9117 I had to send it in for warranty. No word on what the issue was yet. No matter what the air pressure was, no matter what level of compression I had it set at, it would blow through it's travel.
can i use this in my m.1
100% yes, the air cartridge is the same on the M1 and M2 apart from the negative chamber which has a scraper wiper and bigger volume on the M2.