The oil used in the BikeYoke Revive dropper post is a custom blend of oil and an additive that is designed to work in varied temperature conditions and provide both a smooth and consistent action. It is a key component of the dropper post system and should be replaced during a full service that is usually only required if the post is not working as expected or if you accidentally spill some — as I did. The oil can ber purchased directly from BikeYoke, but if you need oil in a hurry or you’re wondering if some suspension oil you already have will work, then read on.

BikeYoke Revive cartridge service

The BikeYoke Revive has a user serviceable cartridge system that allows you to replace the oil in the dropper post without having to send it back to the manufacturer. This is a great feature because it means you can keep your dropper post running smoothly without having to wait for a service or pay for one. The cartridge system is a simple design that allows you to remove the cartridge from the post, drain the oil, refill it and then reinsert it into the post.

I am not going to go into the details of how to service the cartridge in this post, but I will say that it is a simple process that only requires a few tools and some oil. You can follow along with the BikeYoke published instructional video on how to service the cartridge.

BikeYoke Revive oil

There are two recommended oils for the BikeYoke Revive dropper post:

• BikeYoke Sanguine dropper fluid - 250ml
• 96% Mobil DTE 10 Excel 15 with 4% r.s.p No Stick Slip additive

The Sanguine dropper fluid is the oil that BikeYoke sells directly and is the recommended oil for the dropper post. It is also very reasonably priced so if there is stock and you can wait a few days then I would recommend buying it from your local BikeYoke distributor.

From what I can glean Sanguine is actually a pre-mixed version of the Mobil DTE 10 Excel 15 with the r.s.p No Stick Slip additive. This makes sense because the only way to buy the Mobil DTE 10 Excel 15 is in 20L drums, which is a lot of oil for a single dropper post service.

Speaking of which the Sanguine dropper fluid is sold in a 250ml bottle which is enough for a few services given the small oil capacities of the dropper post.

Oil capacities

The BikeYoke Revive dropper post comes in a few different lengths and each length has a different oil capacity.

So as you can see the oil capacities are not large so you’ll get a few services out of a 250ml bottle of the Sanguine dropper fluid, or any other oil you choose to use.

Selecting an alternative oil

Whilst BikeYoke are quite clear about the oil they recommend for the dropper post they do note that the best performance will be achieved with the Sanguine dropper fluid. That said from forum posts by Sacki of BikeYoke they have been discussing the use of alternative oils from the beginning and have tested a few.

Early discussions on the forums reference a specification of 15cSt at 40°C for the oil, but recent technical documents from BikeYoke mention that Sanguine is a 16cSt oil at 40°C. Something within a reasonable range of this should work well in the dropper post.

Do note that we’re talking about cSt here and not the weight of the oil, which does not directly correlate to the viscosity of the oil. Also, this can be noted with the mm²/s unit that is sometimes used to denote the viscosity of oil, but is the same as cSt. You want a suspension oil that is as close as possible to 16cSt or 16mm²/s at 40°C.

Note that this value is taken from the oil and pressure specifications for BikeYoke products document.

Alternative oils

I have found a few alternative oils that are close to the 16cSt at 40°C specification of the Sanguine dropper fluid. These oils may be easier to find as they’re more commonly used in motorbikes.

You are sure to find more oils that are close to the 16cSt at 40°C specification of the Sanguine dropper fluid, but these are the ones that I have found. I managed to find the Motul factory line fork oil 2.5W at a local motorbike shop, and it has worked well in my dropper post - I have not noticed any difference in the action of the post.

Refilling the oil

The easiest way to measure and refill the oil in the dropper post is to use a syringe. I got a syringe from my local chemist and whilst it was only 5ml in capacity with a few syringe refills I was able to measure out the correct amount of oil for my dropper post.

Pressurising the post

Once you’ve changed the oil you will need to repressurise the post with air and a shock pump.

The post is designed to work with a pressure of 250psi, but you can run it at a lower pressure if you want a softer/slower return or a higher pressure if you want a firmer/faster return to maximum height.

Conclusion

The BikeYoke Revive dropper post is a great post that is easy to service and maintain. The oil capacities are small so you’ll get a few services out of a 250ml bottle of the Sanguine dropper fluid or any other oil you choose to use. My post has been running well with an alternative oil and I have not noticed any difference in the action of the post. I do not ride in freezing weather though so if you do then you may want to stick with the Sanguine dropper fluid or performance maybe be affected.