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Mavic unveils Cosmic SLR 45 Disc tubeless wheelset

New all-rounder design drops weight over previous designs by eliminating the need for tape

Mavic is launching a new carbon Cosmic SLR 45 Disc wheelset with Road Tubeless technology that’s said to be easier to use than previously with a fully sealed upper rim bridge that saves weight by eliminating the need for tape. The wheelset is designed for an all-round rider/racer looking for a single do-it-all option.

2021 Mavic Cosmic SLR 45 Disc  - 6.jpeg

Here’s the key info in brief from Mavic before we start:

  • Rim: 45mm deep, 28mm outer width, 19mm inner width, NACA profile
  • Mavic’s Fore technology keeps the rim upper bridge solid to make the rim stiffer
  • Fully sealed UST (Universal System Tubeless) rim doesn’t require tape, saving approx 60g per wheelset
  • Refined rim bed shape makes it easier to mount tyres from any brand
  • Infinity hub platform designed to offer stiffer axle and greater bearing durability
  • Double butted aero-profile spokes
  • Wheelset weight: 1,470g
  • Price: £1,650
  • Available from mid-September 2020

Mavic says that its aims with the new wheels were to reduce weight for faster climbing and snappier accelerations, and to make running tubeless tyres easier.

2021 Mavic Cosmic SLR45 V1 PSD.jpeg

In order to save weight, the Cosmic SLR 45 Disc uses a rim laminate that’s lighter than that used for the existing Cosmic Pro Carbon SL Disc, and eliminating the need for tape sheds more grams. Whereas the Cosmic Pro Carbon SL Disc has a ready-to-ride weight (complete with tape) of 1,590g, Mavic claims a weight of 1,470g for the new Cosmic SLR 45 Disc wheelset.

2021 Mavic Cosmic SLR45 Fore Carbon rim cut.jpeg

You don’t need tape because the upper rim bridge is sealed. Spokes screw into a co-moulded metallic insert that doesn’t sit in the upper bridge. Mavic says that the fact there are no holes in the upper bridge also increases stiffness.

Mavic has slightly updated the the design of its UST rim contours for model year 2021. A wider central groove is designed to make mounting tyres easier, including tyres with wide beads. The hump that ran on either side of this central groove has been removed for easier tyre removal, although Mavic says that the tyre still remains locked on to the rim even at very low pressure.

2021 Mavic Cosmic SLR 45 Disc  - 2.jpeg

Starting with model year 2021 wheels, all Mavic Tubeless wheels will be compatible (safe and easy to use) with all ETRTO-compliant tubeless tyres, ETRTO being the European Tyre and Rim Technical Organisation which seeks to align standards to allow the interchangeability of rims, tyres and valves.

The rim is made to a NACA (National Advisory Committee for Aerodynamics) profile designed to minimise drag and increase stability, and the elliptical spoke shape is said to save the equivalent of 4 Watts at 40km/h over a standard flat spoke (ie you’ll be able to maintain 40km/h at a slightly lower power output).

2021 Mavic Cosmic SLR45 Infinity Disc hub V1 PSD-5.jpeg

Mavic says that the Infinity hub platform offers optimal spoke tension and swapping between a quick release, 12x135 and 12x142 thru axles is a tool-free job.

2021 Mavic Cosmic SLR 45 Disc  - 3.jpeg

The rear hub uses Mavic’s ID360 free wheel system which engages in 9° when you start to pedal thanks to its 40-tooth double-ratchet design.

The axle is 2.5mm thick which makes for greater stiffness, Mavic says. A removable rubber damper allows you to decide between a loud or a quiet freewheel sound, and we know that many people are particular about this!

2021 Mavic Cosmic SLR45  V1 PSD-6.jpeg

Mavic says that the Cosmic SLR 45 Disc tubeless wheelset is “equally at ease on hilly roads and mountain passes, from perfect tarmac to broken roads”.

Mavic divides its range into four performance levels (S, SL, SLR and Ultimate), the Cosmic SLR 45 sitting on the second tier. Although Mavic tyres will still be available after-market in 2021, they'll no longer come as standard with wheels.

Get more info over at

Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.

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