The SKS TwentyNiner floor pump has been a mainstay in our workshop now for years. A lot of companies have started making ultra-low pressure pumps recently to cater to the needs of fat bikers, and SKS has been among them with their Big Wheel pump. The biggest selling point of those pumps is the ability to read small pressure changes on their dials and to have accurate (or at least repeatable) measurements down in the 10-20 psi range. And while that is great for a fat-only pump, a lot of times the gauges miss out by not going up quite enough to give a broader spectrum of use for other low-pressure tires like the 20-30 psi range for cyclocross and the 23-40 psi range for mountain bikes.
So that’s why we looked to the next SKS pump up the line, the Twentyniner. It’s an oversized barrel pump with an easy-to-read gauge that goes up to ~85 psi/6 bar. That’s a bit higher than we might have initially hoped, but in the end let us cover even more ground. Check out how it has done for us after the break…
The two stand out features of the SKS Twentyniner Floor Pump are probably the big gauge and the large diameter barrel.
The gauge is 80mm/3.14″ in diameter and is clearly marked in 1 psi increments up to 85 psi and in 0.1 bar increments up to 6 bar. The gauge’s needle tapers fairly thin at the point so it is easy to see the difference of even 0.05bar, but a bit harder to read anything closer than 1 or 2 psi.
Paired with that visibility, we actually started doing a bit more mixing of measuring in bar and psi depending on the occasion, which I have to say I was leery of but wasn’t such a big deal. Measuring it against a pair of digital pressure gauges (one from SKS and the other from Topeak), the Twentyniner was the first floor pump I have used that accurately reproduced pressures below 30 psi.
The large barrel uses a 40mm/1.6″ diameter and a very long throw to pump tires up quickly. The Twentyniner pump actually sits taller than most standard pumps as well, at 71cm/28″ which means you don’t have to bend over as much, but with a 53cm/21″ stroke may actually be a bit more work for shorter users. It uses a wide flat base that gives it the needed stability to really lever on that long handle, and includes a couple of attachments for pumping things other than tires.
Its head is a fairly typical auto-sensing design for either Presta or Schraeder valves. The odd thing about it is that the lever down (perpendicular to the valve stem) is locked, while lever up is unlocked. This is the opposite of most other pumps, so it took a bit of getting used to, and out of habit I tend to still close the lever whenever I am done with the pump adding a step when I need to pump the next tire again.
The large volume was great when pumping up actual 29″ mountain tires, and even more so when dealing with bigger enduro and plus sized rubber. Once we got it up to the 25 psi range, each full stroke would add around 2 psi, making it fairly easy to dial in the desired pressure. On the other side one of the big reasons we look to the SKS Twentyniner pump in the first place was for cyclocross, and dealing with a 33mm cross tire a full pump might jump 5 psi or more, so we learned to deal with lots of half pumps to get to the desired pressure.
This worked well enough for getting a good estimate for trail riding or starting out on a training ride, but when it came to racing we always broke out the handheld digital gauge for the 0.5 psi increments that made the difference between traction and too much squirm in the corners.
While we would probably been a little happier with the pump at the offset if the gauge had only gone up to 45 psi/3 bar, after using it for a while it became the go to pump for gravel and mixed surface road riding as well. Maxing out at 85 psi, it covered all the ground we needed for pretty much all of our road riding on fat rubber. Here in Prague we don’t ride many tires narrower than 28s on the road, so the Twentyniner pump did a great job of getting those up to pressure quickly.
Another side (and unexpected) benefit of the big barrel is that this pump has done an excellent job at seating tubeless tires. While the auto-sensing head only works when it feels resistance (so it won’t pump air out of the correct opening when there is zero resistance), it was easy enough to screw off, and the hose fits perfectly and snugly on a Presta valve. Like this we seated road, cross, cross country, and even tight-fitting enduro tires, all without the need for a compressor. It certainly isn’t the design intent of the pump, but it saved us a bit of running around to go to a compressor and back, and made tubeless setups a bit less painless.