SRAM X0 XG999 cassette review

Lightweight nine-speed cassette

Our rating 
4.0 out of 5 star rating 4.0
GBP £250.00 RRP | USD $300.00
Sram X0 XG999 cassette

Our review

Cutting-edge design delivers the shifting goods
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SRAM hasn’t given up on nine-speed components, despite being a company that’s at the forefront of the new 10-speed technology.


This frankly beautiful X0-level XG999 cassette is hewn from a single billet of stainless steel, with SRAM employing their PowerDome technology to hack away every last gram of unnecessary material.

This highly intricate piece of engineering has to be seen to be believed. Each of the eight sprockets – the 11T sprocket is separate – is joined by small spacing arms and drops the overall weight to 175g. This saves a huge 100g more than the same ratio X0-level PG990, and about 50g more than a Shimano XTR nine-speed cassette.


The shifting is typically slick with SRAM chains, but we tried it with Shimano and KMC chains too – just to be completely sure – and it performed flawlessly. If weight-saving is your goal, then this upgrade will make your lightweight wheels even flightier.

Product Specifications


Name X0 XG999 Cassette (10)
Brand SRAM

Weight (g) 175
Features Gear 11-32 (11-12-14-16-18-21-24-28-32)
Chain Speed Compatibility 9