Shimano SLX 20mm/Mavic EN521D wheelset£225.00

Strong centrelock hoops

BikeRadar score3.5/5

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.

Guy Kesteven

Freelance Writer, UK
Guy started filling his brain with cycle stats and steaming up bike shop windows back in 1980. He worked the other side of those windows from '89 while getting a degree in “describing broken things covered in mud" (archaeology). Dug historical holes in the ground through the early '90s, then became a pro bike tester in '97. Guy has ridden thousands of bikes and even more components the world over since then and can remember them all in vivid, haunting detail. Can't remember where the car keys are, though.
  • Age: 44
  • Height: 180cm / 5' 11"
  • Weight: 68kg / 150lb
  • Waist: 76cm / 30in
  • Chest: 91cm / 36in
  • Discipline: Strict sadomasochist
  • Preferred Terrain: Technical off-piste singletrack and twisted back roads. Up, down, along — so long as it's faster tfhan the last time he did it he's happy.
  • Current Bikes: An ever changing herd of test machines from Tri bikes to fat bikes and everything in between.
  • Dream Bike: His Nicolai Helius AM custom tandem
  • Beer of Choice: Theakston's Old Peculier (not Peculiar)
  • Location: Yorkshire, UK

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