Serfas ST-17i CO2 multi-tool review

CO2 inflator and multi-tool in one

Our rating 
3.5 out of 5 star rating 3.5
GBP £27.89 RRP | AUD $64.95 | USD $45.00

Our review

Compact space saver and quality construction, but why no 3mm Allen key?
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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.

Product Specifications


Name ST-17i CO2 multi-tool
Brand Serfas

Weight (g) 115
Included in Multi-Tool Allen Key Set Chain hook Chain Tool Flat Screwdriver Nipple tools Phillips Screwdriver Torx T25 for brake disc
No. of Tools Included 17