Vorsprung Smashpot Coil Spring Fork Conversion Kit

Smashpot vs. Stock ZEB

The first-generation ZEB Ultimate has a lot going for it, but its lack of midstroke support was essentially a deal breaker for me; as I’ve hopefully made clear in the “Setup” section, above, fork support is a real priority of mine, and the original ZEB left a lot to be desired there. (The new 2023 ZEB is a big step up in that regard — full review of the new fork coming soon.)

When set up to my preferences — which, again, centered around a very stiff spring for support — small-bump sensitivity is improved by a bit with the Smashpot, and midstroke support is on a completely different planet. But if you opt for a softer spring rate and more balanced setup, the Smashpot has the potential to make a very substantial difference in terms of sensitivity and traction, while still improving midstroke support, too. The Smashpot is undeniably heavier (by a lot) and does give up some fine-tunability as compared to an air-sprung fork, where you can make adjustments by whatever infinitesimal increment you want with a shock pump, for free, but the suspension performance of the Smashpot is so clearly superior to that of the stock fork that I think the overwhelming majority of people will be able to find a setup that works better for them, even if it’s not strictly 100% optimized (I’d love… about a 48.5 lb spring, I think), at least if they can overlook the weight penalty. And the flip side of losing the micro-adjustability of an air spring is that a coil stays consistent and doesn’t require periodic pressure adjustments to maintain a given spring rate, and doesn’t accumulate friction nearly as significantly as an air spring as service intervals wear on.

Smashpot vs. Secus

As impressed as I was with the Smashpot, in a roundabout way, trying it only made me appreciate the Secus even more. The Smashpot does clearly have less friction and therefore better small-bump sensitivity and traction, but the Secus does a remarkable job of emulating the overall spring curve of the Smashpot and therefore getting me the improved midstroke support that I sought out of the original ZEB, all with a much more modest weight penalty (about 130 g), and while preserving the adjustability of an air spring. And as someone who’s generally more focused on getting the support I want out of a fork than finding maximum sensitivity and traction, that’s a tradeoff I’m pretty happy to make.

But there are definitely folks who would be better off with a Smashpot, too. In very general terms, I think they break down into a few groups:

(1) People whose top priority is sensitivity and traction. The Secus can make a real improvement over the stock ZEB on that front without completely sacrificing midstroke support too badly if you chose to set it up with sensitivity in mind (check out our Secus review for a whole lot more on that) but it can’t match the low friction and initial smoothness of the Smashpot, no matter what you do with the setup.

(2) Set-and-forget types who don’t want to deal with maintaining air pressure or servicing their fork as often to maintain performance. The caveat here is that the Smashpot doesn’t actually change the manufacturer’s recommended service interval for whatever fork you might have, and you still need to take care of the lower leg oil, wiper seals, and damper as per usual. But due to the extra oil volume in the spring leg, and the elimination of a bunch of dynamic seals in the air spring, a Smashpot-equipped fork’s performance definitely does not degrade as quickly as an air-sprung one does as the last service fades into the rearview mirror. And the spring rate won’t change due to gradual air pressure loss, changes in temperature, and so on.

And conversely, the Secus is likely a better option for some folks:

(1) Riders who want some combination of improved midstroke support and/or small bump sensitivity, but can’t stomach the weight of the Smashpot, especially if improved support is the higher priority.

(2) Folks who really care about dialing in exactly the right spring rate and want to preserve the ability to do so quickly and easily with a shock pump.

(3) Bike flippers who want to be able to sell their bike in the stock configuration, and move the upgrade over to a new bike. A Secus installation is easily reversible; a Smashpot one likely isn’t, somewhat depending on the specific fork in question.