FSA OS-99 road stem review

Lighter than carbon, strong as can be

Our rating 
3.8 out of 5 star rating 3.8
USD $99.00

Our review

Strength and substance - but not weight - over style in a stem with enough fore and aft variance for most riders
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The US$99 FSA OS-99 alu road stem doesn’t have the gloss carbon weave flash of its popular brethren, but at 98g, is one of the lightest stems available, which gives it instant street cred in our book.


As the new standard diameters have encroached and finally settled (1-1/8-inch steer clamp/31.8mm handlebar bulge clamp), manufacturers like FSA can focus on thinning the material a bit more. At first glance there’s not much difference in its appearance, but the forged alu OS-99 can certainly boast a number of features: titanium hardware (two pinch bolts and four face-plate bolts); CNCed 7075-T6 aluminium, and a 35mm stack height (which is pretty standard, and makes it easy to retrofit).

While a removable face plate makes dialing in your position a little easier, it’s still a challenge sometimes to get the right stem rise to put you in the correct position on a road bike. The +/- 6 degree rise of the OS-99 stem provides enough variance for most riders, but can be limiting to those needing a higher position if you’ve run out of steer tube spacers (this is why it’s critical to measure before you cut the steer tube).


After a few rides I settled into a comfortable position with the -6 degree position. It’s a little tedious fiddling with four face plate bolts, but the weight saving is worth the hassle. Overall, the FSA OS-99 road stem gets my vote for the best plain-looking stem on the market. Compared to heavier and flashier carbon stems, you can’t go wrong.


© BikeRadar 2008

Product Specifications


Name OS-99 stem (US) (08)
Brand FSA

Cap Bolts 4
Weight (g) 98
Available Colours Black Anodised
Steerer Size 1 1/8
Material 7050 Aluminium CNC Machined
Stem Length/Reach Options 100mm 110mm 120mm 130mm 80mm 90mm