Durability
I’ll start right out by saying that I don’t have enough time to say whether this will or will not be a durable post, but I can make some educated observations based on the design. The Transfer post is a cable-actuated hydraulic post – it is not a mechanical post like the DOSS. So, making the jump that I made in the intro that the durability of the DOSS might be representative of the Transfer could be a bit of a stretch. However, one would think that Fox would take the know-how they developed with the DOSS and apply it to the Transfer, and that they likely held it to the same high standards for product testing.
Before I jump into the next bit, let’s talk some general seatpost tech details. Hydraulic posts are filled with air and oil. The air acts as the spring while the oil is used to control the motion of the post. It locks it into place when the valves that allow it flow are closed and those same valves slow the motion of the post upon return. Most hydraulic posts use an IFP or Internal Floating Piston to keep the air separated from oil. This is a simple piston with seals around it. The most common failure modes of hydraulic posts all involve air displacing oil. Once air is mixed with the oil, the oil is no longer able to lock the post into place.
The key internal differences between the Fox and other hydraulic posts that might affect durability are: 1) it has a pressure relief valve that compensates for temperature variations or external pressure variations that come from elevation changes. 2) it uses a spool valve to control fluid flow. This is opposed to a simple orifice like on other droppers. And 3) they have tried to minimize hydraulic pressures inside the post.
The combination of the three changes is likely to keep pressure from spiking and breaking the seal around the IFP, potentially reducing the chance that the Transfer will turn into a suspension post because air ends up in the wrong place. Of course that’s all hypothetical, and the limb I’m on is starting to feel pretty weak. With more technical information I could make a better stab at this, but in lieu of that, I’m just going to keep riding the post to see how the durability plays out and I’ll update this review with any new info.
Comparisons
Vs. KS Lev
I quite like the light action of the KS Lev posts, and with the addition of a Specialized or Race Face lever, the ergonomics are great.
The downfall of the KS posts is less than ideal durability and an awkward installation process.
I hope the Transfer will be superior on both counts. So far I can only tell you that it is easier to install.
Vs. Rock Shox Reverb Stealth
I prefer the lever on the Transfer and I enjoy the ease of installation and servicing provided by the cable actuation. I’ve not been impressed by the reliability of the older Reverbs, but I haven’t had the chance to try the new, simplified version.
I’ve had good luck with the Transfer so far, but I wouldn’t have expected to encounter issues yet either. Based on past experience and the lever, I’d choose the Transfer.
Vs. Thomson Elite Covert
These two posts are very similar. The one spot I really give the Fox the edge is with the lever design (if you’re running the underbar version in place of a front shifter). That’s enough that I’d choose the Fox though. With the Thomson I’d have to buy it with a lever and then also buy the Thomson under bar lever. Note though, that the Fox lever is compatible with the Thomson post. So, if you already own the Thomson post, I’d recommend going out and buying a Fox under bar lever.
Bottom Line
The Fox Transfer post is a great option, and it works smoothly, and the lever is ergonomic and easy to use. I see the less expensive performance post being really popular as black blends in better with most bikes than Kashima gold. I’ll be continuing to ride the post and will report back on its durability. If it beats out the KS posts, I’ll have a new favorite.