IndustryOutsider is supported by its readers. When you purchase through links on the site, we may earn an affiliate commission. Read more here.
At last count, there were eight complete, or partially complete bikes in my house. (And at least three outside, but who’s counting?) And friends are always bringing me other bikes to tinker with or adjust. So when Serfas offered to let me try out some of their folding multi-tools, each of which has a built-in CO2 inflator, there was no shortage of available subjects to test them on. With 13, 15, or 17 functions, each of these tools packs plenty of features, but you’ll need to choose wisely. Read on to see which one is best for your needs.
Despite its compact size, the $36 ST-13i manages to offer 13 different functions. A U-shaped piece of steel is folded over, forming the base for this tool, with the CO2 inflator at one end, and the various other bits lined up in two rows on the opposite end. You’ll find 1.5, 2,3,4,5, and 6mm keys taking up one side, with a bottle opener/flat blade screwdriver keeping them company. The remaining Torx 25 and 30, along with the phillips screwdriver and 8mm allen key, fold out from the other side. Being so compact could be a disadvantage on fasteners that require plenty of torque, but that’s a plus when dealing with carbon fiber that can be damaged if overtightened. Given the choice, this is the one I’d be most inclined to carry.
Moving up in features is the ST-15i, which is the largest of the trio, mostly due to the inclusion of a pair of tire levers, one on each side. This has the same tools as the ST-13i, less the bottle opener. That pair of tire levers count as a single function. A handy hinged compartment stores three glueless patches, and a square of sandpaper, which count as two. But you won’t feel short-changed the first time you have to patch a tube that’s got some talc, as the sandpaper may make the difference between the patch sticking, or you walking home. As the bulkiest of the bunch, it’s not my favorite, but it does allow you to really tighten down bolts when necessary. I seem to gravitate towards rims that run large and tires that run small (in diameter), and break more than my fair share of levers. The included ones also have sharper edges than you would want to give a ham-fisted operator like myself, but if your tires aren’t overly tight to the rim, and you’re patient when changing flats, then having some tools, levers, and a CO2 inflator all in one place is probably worth the weight. Looking at it that way, the MSRP of $40 is pretty reasonable too.
Boasting the most functions and highest price, the ST-17i has 17 features and a $45 MSRP. That gets you 2,4,5,6, and 8mm allen keys, 25 and 30 Torx, both screwdrivers, a chain cutter, chain retainers, as well as 3.23, 3.3, 3.45, and 3.96mm, spoke wrenches and the CO2 inflator in a package not much larger than the 13, and about about 2/3 the size of the 15. Squeezing a chain cutter into such a compact tool requires a bit of dexterity use. The handle is flat, and one of the retainers will get overly friendly with your thumb. But if you need one in a pinch, this will get the job done. Using the CO2 is easier if you unscrew the handle for the chain cutter out of the way (it locks in position via a well-placed magnet). Once out, and you’ve also got an emergency spoke wrench.
None of these are intended to replace full-size tools. They’re for quick adjustments and road/trail side repairs, and at that, they work as advertised, without being so big or weighing so much that you’re tempted to leave them at home. Serfas seems to have found a good balance between features, ergonomics, and price. And honestly, the CO2 inflator is not only a functional addition, but the color is eye-catching, and seems to make them a bit more desirable. Your friends may be envious, even as they watch you fix your ride.