X-Fusion O2 RCX shock review

Updated rear suspension

Our rating 
4.0 out of 5 star rating 4.0
GBP £339.99 RRP | USD $380.00
X-Fusion O2 RCX rear shock

Our review

Internal changes make X-Fusion’s proven O2 shock a top-class performer and proper Fox hunter
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X-Fusion have made massive advances with their forks in the last couple of years, and subtle changes to their shocks have now put them right up with the established leaders. Structurally, the O2 RCX hasn’t changed since we last reviewed it, but the detailing of the latest shocks makes a huge difference. 


The shock is impressively smooth and supple straight away; previous models took several hours to free up. With the RCX compression damping lever fully open, it’s so plush over small stuff it feels as though you’re not running enough pressure at first. Start pushing hard, though, and the new damping tune does a brilliant job of keeping travel working within its mid-stroke sweet spot most of the time.  

The low-speed compression damping added by the intermediate 2 and 3 settings is exactly that too – actual low-speed compression damping rather than a fixed-position platform damping setting. 

This means control of suspension movement from small-sized or slow-speed body weight/braking pedal movements at any point in the stroke, not just at the start of travel or a specific sag point. This lets you select a soft or firm baseline that still sucks up bigger hits or drops without any sense of wallow or bounce before it regains control.

It remains consistent throughout the stroke, too, whether the suspension is unloaded coming out of a compression or you’re deliberately squashing the bike into a berm. 

X-Fusion have also introduced a range of different pre-order tunes for different bikes. If the VPP2 we’ve tried on a test rig is anything to go by, they’re well worth having too. Even with the ballpark pressure setting, the combination of positive pedalling and stability through corners instantly made the Santa Cruz feel sharper and more precise than with the Fox CTD we took off. 

On deliberately testing sections – jumping off boardwalks onto rocky upslopes at full power or turning in across root spreads – the rear end was remarkably glued. It wasn’t kicking around or squatting even out of deep compression under maximum power, and kept consistent traction whatever the rider or trail were doing. 

It’s a sign of how good the shock is that it pushes the ride emphasis back onto the fork, and we suddenly became really aware of how well set up – or not – the fork was. 


This article was originally published in Mountain Biking UK magazine, available on Apple Newsstand and Zinio.

Product Specifications


Name O2 RCX shock (13)
Brand X-Fusion