Mavic launch Cosmic Carbone 40 clincher

New 1,545g carbon clincher wheelset from French wheel brand with TgMAX braking surface

by Mat Brett   March 13, 2013  

Mavic’s first ever carbon fibre clincher wheelset uses a new 40mm rim that features an aluminium and carbon fibre construction, with a proprietary heat treatment process, TgMAX, to prevent overheating during prolonged braking.

The 40mm rims use a lightweight alloy extrusion with a carbon shell bonded around it, with the inside filled with foam. They’ve been shaped in a wind tunnel, and have a noticeably rounder and fatter shape than the previous Cosmic wheels, more in line with the likes of Zipp and Bontrager.

One of the problems with carbon rims in the past has been the build up of heat on long descents. Friction from the brake pads causes heat and that affects the structural integrity of the rim. In plain English, things can become dicey when the resin gets hot. The biggest concern with carbon clinchers is the heat buildup that can lead to inner tubes exploding or, worse, a structural failure of the rim. I've experienced exploding inner tubes and it’s not a pleasant experience, I can tell you.

Solving this problem has been the big development with these wheels. Mavic have developed TgMAX technology, which consists of two types of resins and using a proprietary heat treatment process to construct the braking surface. The glass transition temperature is the point at which the resin gets hot enough to revert to its liquid state. Mavic’s testing on a 10km downhill with a 100kg rider revealed temperatures at the braking surface can exceed 250°C.

Mavic claim their testing shows that they've been able to reduce the braking distance compared to other carbon clincher wheels in the wet. They also claim, because of the aluminium and carbon construction, that the wheels are much stiffer than other aftermarket wheels, reducing rim deflection between the brake pad by 50%.

Ease of maintenance has been a consideration and the spoke nipples are easily accessible at the rims. Mavic’s Fore technology uses threaded inserts at the rim, and there are no spoke holes in the rim bed. No hidden nipples mean you don’t need to remove the tyre and rim tape to adjust the spoke tension here.

At 1,545g, these aren't the lightest wheels. For comparison, Zipp claim 1,475g for their 45mm-deep 303 Firecrest clinchers. The Cosmic Carbone 40s aren't far off, but it appears Mavic haven't been too concerned with weight, but focused on safe and reliable braking. They're pitching the wheels at sportive and gran fondo riders, a big market for carbon clinchers, and amateur racing cyclists who want an affordable wheel that balances stiffness, weight and aerodynamics. They’re priced at €2,000, but there’s no UK price yet.

Mavic continue to produce wheel and tyre systems, and the wheelset weight with thir 190g Yksion Pro clincher tyre is 2,085g.

We can’t wait to get our hands on a set and see just how good the braking surface really is, because they sound very promising.

www.mavic.com

12 user comments

Oldest firstNewest firstBest rated

Inner tubes (maybe only latex ones?) can fail from the heat of braking on a descent too, can't they?

two wheels good; four wheels bad

posted by cat1commuter [1380 posts]
12th March 2013 - 13:51

2 Likes

cat1commuter wrote:
Inner tubes (maybe only latex ones?) can fail from the heat of braking on a descent too, can't they?

Yes they can, both regular and latex tubes. Carbon rims just can't dissipate the heat generated from braking as quickly as aluminium rims

David Arthur's picture

posted by David Arthur [1749 posts]
12th March 2013 - 16:38

2 Likes

looking good for clinchers ...

posted by Karbon Kev [682 posts]
12th March 2013 - 18:30

3 Likes

I dont see the point though...

Cosmic SLE - 1620g - Exalith Braking, Clincher
Cosmic SLR - 1595g - Exalith Braking, Carbon Spokes, Clincher
Cosmic Ultimate - 1185g - Carbon Braking, Tubs

At 1545g I think I'd rather take the longevity of Exalith and Clincher over the 50/75g savings from this new wheel??

Oh and they're new hubs rattle like a pig!! Sounds like keys jangling.

posted by charlierevell [34 posts]
12th March 2013 - 22:09

2 Likes

What's this - no disc brake options?!

Pah! Crying Crying Crying Crying Crying Devil

posted by cllr hodgen [45 posts]
13th March 2013 - 15:02

0 Likes

What's the point of making an aero aluminium rim and then giving it a cosmetic carbon wrap? Other than aesthetics and reduced braking capabilities that is?

Surely the point of carbon is to reduce the weight, if you’ve got an aluminium core you’re adding weight, or are Mavic saying that alu is actually a better and lighter choice than carbon when it comes to clincher construction? Thinking

posted by bikewithnoname [33 posts]
13th March 2013 - 15:38

0 Likes

Coming to a London winter commute near you................

Mavic hubs are sh*t too.

posted by 6654henry [58 posts]
13th March 2013 - 16:08

2 Likes

There aren't any hills/mountains big enough in England to worry about brakes over heating Wink

Municipal Waste's picture

posted by Municipal Waste [196 posts]
13th March 2013 - 19:05

1 Like

there are in wales Wink

posted by welshcyclistguy [14 posts]
13th March 2013 - 23:06

3 Likes

Long ago Mavic used to be world's finest, these days are long GONE, there is so much better wheels with half price tag i.e. Miche, Rar, PMP,Marchisio, the list is long..

posted by Vinerman [40 posts]
14th March 2013 - 7:25

0 Likes

£2,000. Why????

For £285 and just 100 gms more you could buy a pair of Campag Zondas. I've just replaced my 7 year old pair which have only needed truing once it all that time - and that was after a single spoke replacement. If you want to carry less weight up hill lose some weight.

My back wheel was hit with a stone which caused a 3cm crack in the rim. I sailed down a 2 mile hill and home and I only noticed the damage when I got the bike home and hung it up.

I suspect with carbon 'catastrophic failure' could have been the result and I wouldn't be writing this at all.

Silly me. You're probably right....

MercuryOne's picture

posted by MercuryOne [1093 posts]
14th March 2013 - 16:36

0 Likes

Or, maybe, it wouldn't have broken at all Big Grin

Basically it's impossible to tell what might have happened so suspicions are fairly pointless

posted by atlaz [158 posts]
14th March 2013 - 16:57

5 Likes