2014 Ursus C25 and C50 carbon fiber road bike wheels use a woven copper brake track

Italian wheel manufacturer Ursus has turned to metallurgy to combat heat related braking issues on their carbon rims.

The 2014 Ursus C25 and C50 carbon clincher wheels get a new 1mm thick copper weave in the brake track that they say drastically reduces braking temperatures. It’s bonded in during construction, so it shouldn’t wear off. That’s combined with their HTG high temp resin to dramatically reduce heat buildup. They’re saying braking temps can run as high as 300-400 degrees C, and these reduce it down to 70-100 degrees C.

Weights are 600g front /750g rear (C25) and 695g/845g (C50). Retail is $2,400 per pair. Both are 20mm wide at the outside, and they’re 25mm and 50mm deep respectively.

Closeups of the copper and the actual production finish, plus their new mountain bike wheels, below…

2014 Ursus C25 and C50 carbon fiber road bike wheels use a woven copper brake track

A close up view of the copper weave.

2014 Ursus C25 and C50 carbon fiber road bike wheels use a woven copper brake track

On production models, it won’t be quite so coppery looking. Here’s a finished wheel…

2014 Ursus C25 and C50 carbon fiber road bike wheels use a woven copper brake track

…and a close up of the production brake track.


They’ve also added mountain bikes wheels to the line. The top model is the carbon rimmed Diablo, which comes in 27.5″ and 29er. Rims are reinforced unidirectional fibers that are 25mm wide and 20mm deep. They’re built with Sapim spokes using Ursus’ SLN (Self Locking Nipple) system that places nylon bushings around the nipple to prevent binding or loosening. They come in at 615g F/783g R for the 27.5″ hoops and 650g F/825g R for 29ers.


Below that are two alloy models below it called Viper and Spark, both with anodized black aluminum rims. The Viper (above) comes in all three wheel sizes with an 18mm deep asymmetric rim, offsetting the spoke bed for more even tension. They’re built with the SLN nipple system, but use different rim widths and spokes for the larger two wheel sizes. The 26″ is a bit lower end with Sapim Force spokes and a 22mm wide rim…and it’s a bit heavier for it The 27.5″ and 29er get CX-Ray spokes and a wider 25mm rim. Weights are 730g F/855g R (26″), 650g F/818g R (27.5″) and 685g F/815g R (29er).


At the low end are the Spark, a basic alloy wheel. It also comes in all three wheel sizes, uses SLN and has a 23mm wide/18mm deep rim. Weights are 900g F/1140g R (26″), 925g F/1165g R (27.5″) and 975g F/1195g R (29er).



  1. So how exactly are a $2400 pair of 600+ gram 25mm deep Ursus copper/carbon rims superior to a $160 pair of 450 gram 25mm deep H+ Son Archetypes?

  2. This is really exciting! I ride carbon tubulars. But I would consider these clinchers before I would consider disc brakes. Besides, Lightweight, Zipp, Reynolds and Enve now have resins to cope with heat dissipation.

  3. Malol, the same was said for MTBs 15 years ago. Now, you wouldnt have your mtb any other way.

    The manufacturers are going to shove it down our throats. There is no point in resisting.

    Jump on the band wagon. Embrace it!

  4. Alex K: The UCI has not approved disc breaks for road bikes as of yet so that is why there is so much attention to money spent on improving rim brakes.

    MaLóL: I will disagree with you. From personal experience, disc brakes perform much better in wet and sloppy conditions than the rim brakes do. In normal, dry conditions, your argument may be valid.

  5. I hope they make an option to have the copper visible if that’s feasible from a performance standpoint. It’d look great on a black frame.

  6. @Malol: It is exactly the other way around. Reliable day to day performance of disk brakes vs. useless gram counting for show.

  7. LOL. More disc brake for road bikes chatter on Bike Rumor. I wonder how many of the advocates for disc brakes on road bikes have much of a racing resume beyond cat 4, because I haven’t heard a single person in my local scene pining for them. And I live in the Midwest, where we get a lot of terrible weather. A lot of talk about tubeless, nothing about disc brakes.

  8. Reynard, your “scene” is not the world. Perhaps you should move somewhere with real mountains and rain. In places like the PNW its not unheard of for commuters to burn through an aluminum rim in a year. And it’s not unheard of to burn through a set of pads racing in a downpour.

    Aris, brakes don’t work from heat, they work on friction, which heat is a product of. Simple physics.

    One of the long standing problems with carbon is that it retains too much heat and can compromise the resin (and glue in the case of tubulars). Which is the high temp resin is even mentioned.

  9. Right, and your scene isn’t the world, either. One size fits all doesn’t work in clothing, and doesn’t work in bikes. It seems like the industry is bound to push this on everyone, regardless of need. I can’t see them taking hold for a while since there’s no UCi approval and you’ll be totally hosed by neutral support at crits and road races. I can’t wait to see a dude who needs a wheel and support has nothing with a disc.

  10. All I’m saying is that there are enough places in the world to justify their use. And from what I’ve heard, UCI is looking at the issue and it is likely only a few years away from approval.

    The industry is pushing it, but there are a lot people who want it too, even if they aren’t where you live.

    Not sure why you’d take pleasure someone else’s misfortune though, that’s pretty low.

    And earlier I meant Alivs, not Aris.

  11. @alvis: there is an optimum temperature range for brake pads, and it’s pretty low. It is certainly well below the high temperatures that can be generated on CF rims, temperatures that can reach glass transition temps.

    Where does the energy go? The energy is distributed through the copper to a much larger area and is lost much more quickly through convection. The thermal conductivity of copper is roughly twice that of aluminum (from 0-250°C), but that larger conductivity is offset somewhat by the smaller volume and surface area of the copper mesh in these wheels compared to that of an aluminum rim.

  12. Reynard2ki, you need to take off the binary blinders. Yes, there is no doubt the fraction of road bikes sold with disc brakes is going to go up significantly, maybe even dramatically, over the next few years. That does not mean that all bikes will have them. There will likely be a market for rim brakes for a very long time to come.

    Are disc brakes going to make it into the road racing scene and even the pro peloton? Yup. It’s going to happen no matter your snark.

What do you think?