Many riders carry some form of multi-tool and tyre inflation device. The Serfas ST-17i combines both, with a CO2 tyre inflator (Presta valve only) and a comprehensive multi-tool in a 115g package that we're pretty sure McGyver would've wished he’d had.
The multi-tool was fully functional, with common sizes of spoke nipple, screwdriver, Allen keys and Torx keys covered. Strangely a 3mm Allen was amiss from the tool, which is odd – it's a more commonly used size than the included 2mm key. The stubby 8mm Allen was hollowed – a classy weight reduction trick. The T30 bit was a nice touch – it's something you need for most chainring bolts and is often excluded from multi-tools.
Using the 67mm (2.6in) tool as a handle for the chain breaker meant there was plenty of leverage available. The little open wrench/spoke wrenches doubles as the pin driver handle, and afforded plenty of leverage. Magnets hold the handle in place when not in use. We especially liked the chain-shaped nook that held the chain link in place during operation.
The threaded CO2 inflator was controlled by slowly undoing the CO2 canister (not included). It's sealed when tight; loosen it and the gas is released. Given it’s for emergency use only, it worked well, but its vertical nature meant it was fiddly to use with the canister situated between the spokes.
Assuming you don’t already own a CO2 chuck or multi-tool, the ST-17 represents decent value. It’s not the most ergonomic tool on the market, but for emergency use, it means fewer pieces to lose.
UK customers will need to buy online – shipping from the Serfas website costs USD$16.90.