COSMIC CARBONE SL upgrading to COSMIC CXR 60mm / 80mm (COMETE)

This is not a review, just a brief jotting down of a few wheel-based experiences.

I did a lot of the Age Group racing 4 or 5 years ago and it seemed that very many age groupers had the COSMIC CARBONE SL wheels. I was no exception. Maybe I just noticed them more as I had a pair AND because they have COSMIC emblazoned on them in thick white lettering.

At the time, I got mate’s rates on a pair from somewhere in Brighton (I think £600-£700??? for the pair, I forget) but they were coming in at over the £1000 mark for the pair at normal retail prices.  I had the metal rimmed, 52mm ones and subsequent full carbon versions pushed the price up WELL over £1000.

I’ve been using the CXRs for the last 3 months for IMUK, for HEVER and for several other races and TTs of various distances. Often with another ‘special’ disk swapped in on the rear. I did NOT get mate’s rates on the CXRs but a rear will be something like £750 (60mm) to £900 (80mm) and a front something like £700 (80mm) or £625 (60mm). So those prices are broadly indicative of an equivalent MAVIC replacement  for the CARBONE SLs.

WERE THEY BETTER? It’s virtually impossible to say. I could cite a few PBs on the new wheels compared to the old wheels but I would certainly hope that I have got fitter in the intervening period. They certainly look sweeter 😉

WHAT’s NEW?

I’d say they seem pretty much like a totally different wheel to me. Ok it’s round with spokes. but you get the point.

The wheel width is wider at the rims (27mm)  in line with general trends for wider wheels/tyres. This made it a PITA to get onto my TT bike as I ran out of adjustment on the brake calipers. So I had to file the brake pads down before I could use them

The rim sidewall is carbon ‘fairing’ bonded to an aluminmum rim (see comments below, ty) and so this requires Exalith pads (link to: mavic.com). Exalith pads are a harder than normal compound and can be used on ‘normal’ rims but wear our normal rims faster. The RIMS are almost “serrated”. As my newly filed pads settled in they made a REALLY loud screeching noise. In my personal experience the braking was notably superior with these wheels on my TT bike which has a pretty rubbish (ineffective) brake lever setup. I actually stop now rather than wondering if I will…always nice to know.

The innermost part of the fairing is more rounded near the centre than that of the CARBONE SL, presumably that’s more aero?

Apparently the CARBONE SL are1755g and the CXR is 1590g.

However the biggest difference is where the rim sidewall meets the clincher tyre. MAVIC add a ‘blade’ (part of their CX01 technology) – essentially this is a wheel-sized, circular ring that clips on to the wheel and snuggles up to the tyre. There’s one for each side and they create a ‘clearly’ more aero surface between rim and tyre. This BLADE is not integral to the wheel being able to be used to get you from A to B; so if you got a puncture you would not have to re-attach the BLADE. Re-attaching the blade is fractionally fiddly but I was lucky enough to never have to do that on the road. It would add an element of annoyingness to a group ride.

The BLADE may not be legal under UCI rules as it is non-structural but it’s fine for your average triathlon 😉

So if you look inside the wheel, between the rims there are two ridges; one to retain the tyre and the other to retain the BLADE. You can perhaps just see that on one of the above images.

I’ve already said that the braking seems better. I couldn’t tell any difference with the handling. The CXR did have more wind noise and that could imply wasted energy and less aeroness. That comment was not as scientific as a wind tunnel mimicking your daily wind vectors…but I don’t have a wind tunnel.

WORTH THE UPGRADE:? I think you might soon find the CXRs hard to get hold of. They might be a bit faster than the CARBONE SL, I guess. If you’ve just smashed up your old wheels then, yes, go for it. But I can’t see a particular reason to upgrade. Although ‘blowing some cash’ is often as good a reason as any 😉

Don’t get me wrong, I like the CXR more than the CARBONE SLs and they seem to me to be a better wheel.

2018: The COMETE is the replacement product for 2017/8 and beyond. (Link to: MAVIC.com)