Shimano SLX 20mm/Mavic EN521D wheelset review

Strong centrelock hoops

Our rating 
3.5 out of 5 star rating 3.5
GBP £225.00 RRP | USD $372.42
Shimano SLX 20mm/Mavic EN521D Wheelset

Our review

Burly new oversized hubs laced onto classic hardcore rims to create a tough centre lock disc wheelset
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Shimano’s 20mm hubs are always proper barrels, but combined with Mavic’s classic all-mountain rim these SLX hubs form a formidable trail/freeride light wheelset.


The rims are the ancestors of the old 321 – effectively the first mid-width trail rim – and they’ve inherited the same superb strength and stiffness.

There are 32 well tensioned DT Swiss Competition double-butted spokes hooking into the large flanges on the oversize front hub, so you get maximum gain from your 20mm axle setup in terms of tracking accuracy.

The quiet running rear isn’t quite as tight as it uses a conventional flange, but it certainly doesn’t wander however hard you try to warp it through turns.

The fast reacting freehub helps offset the heavy weight too, making it a decent trail wheel despite straying over the 2kg mark.


The adjustable bearings will give impressively long life if you look after them, although centre lock-only disc mounting is restrictive.

Product Specifications


Name SLX 20mm/ Mavic EN521D Wheelset (09)
Brand Shimano

Weight (g) 2110
Front Wheel Weight 969
No of Holes (Front) 32
No of Holes (Rear) 32
Rear Wheel Weight 1141