I recently bought myself a pair of 2011 Mavic Cosmic Carbone SL wheels and wanted to share some of my first impressions/thoughts about them as they seem to be a wheelset that quite a few people are curious about.
I’ve never owned or ridden deep section wheels before, which will probably explain some of my comments below. So far, I’ve only ridden about 120km on them on three separate rides but it’s been enough to make some observations.
What attracted me to these wheels versus others?
When I started searching around for decent, sensible priced aero clincher wheels I found some reviews and comments online that really helped me. Technically these wheels are simply an alloy rim with a carbon fairing. This means that you get the durability and braking benefits of an alloy clincher combined with the carbon fairing for aero effect. I looked at tubular wheels when I was researching aero wheels but I’m not ready to make that jump yet as I’m not especially mechanically minded and the thought of changing punctured tubs frightens me compared to the simplicity of changing a clincher puncture. In all fairness these wheels maybe a stepping stone to tubulars for me – time will tell.
In my research on the Cosmic Carbone SL I read that these were strong, durable, effective (at being aero) and comfortable wheels. This combined with Mavic’s 2 year warranty and reputation for excellent back up service helped greatly too. To get the “big” negative out of the way first – I was concerned about the weight of the SLs at 1755gms in Shimano/SRAM M10 guise. I wondered about opting for either the SRs or the SLRs (with the cool Exalith brake surface and bundled Mavic tyres) but you’re only looking at a weight saving of about 140gms – not a lot in the grand scheme of things for quite a bit more cost.
In fairness, I’ve owned low profile alloy clinchers that weighed about the same as these and they seemed ok but for the last couple of years I’ve been riding clincher wheels weighing in about 1500gms a pair – so I wasn’t over the moon about pushing another quarter of a kilogramme of rims around (I’m not the most powerful of riders!). I also made the fatal mistake of looking at the weights of some of the top tubular wheelsets – like Lightweights (in tubular and clincher) and at the Cosmic Carbone Ultimates and then the SLs looked really heavy at nearly 3/4 of a kilogramme heavier than some of those wheels. Fortunately looking at the price of these high end wheels helped bring me back down to earth and put my concerns about weight into perspective.
The final piece in the puzzle was reading some answers to someone else looking at which model Cosmic Carbone they should buy and the feedback was – buy the SLs – they are the deep section aero clincher you can ride with confidence every day over any kind of road surface without any problems. Normally I’m the kind of buyer who wants to buy as far up the range as they can stretch their credit card, but with so much positive stuff out there for the SL and not being 100% sure that deep section wheels are going to be my thing on the hilly roads around where I live – I pushed the button and ordered the SLs.
The three rides these impressions are based on are a mostly flat 30km ride with someone I didn’t know well over roads I’d never seen before. A 35km blast on my own around roads I know like the back of my hand that include some small climbs and a 65km ride today with my friend Warren including some bigger steeper climbs (including one that averages 7.0%).
– They look fantastic (to me anyway). I think Mavic have done a great job with the graphics on the wheels and they look particularly good with a white bike like mine.
– I love the fact that they are an alloy rim as I can continue to use the same brake pads as my Ksyrium and Easton alloy clinchers. The alloy braking surface keeps things simple – no issues swapping between my other wheels & good stopping in all conditions.
– They’re incredibly comfortable. The Diablo I’ve been riding them on so far is a stiff race bike – but these wheels definitely make the bike more comfortable. This is always a big plus in my book – comfort is very important to me.
– They roll really nicely. Once you’re up to speed they roll along beautifully and that may even get better as they do more miles.
– The weight – yes, they are a bit heavy but once you get them rolling they hold their momentum incredibly well and if you get onto someone’s wheel you’ll work at least 10% less than normal to stay there.
– They are definitely fast. I’ve set personal bests on every ride I’ve done so far with these wheels including the 7% climb I mentioned above.
– The Mavic brand gives me confidence that the wheels will be durable and in the unlikely event there is a problem that Mavic will help me sort it out (not to mention the 2 year warranty)
– The weight. At low speeds, climbing steeper hills, changes of pace – in all of these situations the wheels “feel” sluggish. In fact on my ride with Warren today I wondered out loud if I should keep them at one point – it was just feeling like a big effort to get them spinning.
The strangest thing about these wheels so far is that for a good chunk of the riding I’ve been doing – they’ve felt slow. My head has been struggling (as have my legs) with the feeling that the “extra” weight feels slow and is making my legs battle more for speed. However, the data recording my rides says otherwise and not just the data – my riding companions on both the first ride and today with Warren have said the wheels are fast and that I’m riding fast with them. I’ve done personal best times on all 5 Strava segments that I’ve ridden on in the last two rides including today when I felt sluggish for the whole ride.
On my ride today I kept thinking that they will be great training wheels as the extra weight I’m pushing with them (on the rims) is going to strengthen my legs more over the next few months than the lighter alloy clinchers I’ve been riding as I felt like they were hard work to push over the rolling hills around where I live. Then I looked at the data and thought – maybe that 250 gms over my normal wheels is just the price to pay for better speed once you’re at speed. I seem to be getting some benefit even at 15-20kmh when climbing, which isn’t something I was expecting to find.
Perhaps some of this is simply in my head as I think I should be riding faster on the Cosmics – so I’m pushing a bit harder as it’s going to be embarrassing when I’m passed by a guy (or girl) on a £400 clunker whilst riding these wheels and I know it will happen at some point as I’m not that fast. I think another factor is that my NeilPryde’s have standard double chainsets on them and I’m also still adjusting to them after the best part of 10,000km on a compact with a 12-27 rear cassette. My legs have definitely been feeling the difference. So in this respect I feel the Cosmic Carbones are a small double whammy for my legs.
The early conclusion:
Overall I’m really impressed. The Cosmic Carbone SL wheels look fantastic on the bike, are comfortable, roll well, brake well and most importantly are fast for reasonably sensible money. Throw in the 2 yr warranty and the reputation for durability and dependability and it looks better and better. The downside is the weight – but it’s also definitely an upside and for me right now, the jury’s still out on whether the extra weight is really a problem. It’s definitely making my legs work harder especially combined with the gearing I’m using – but I’m seeing the benefits of greater speeds on the rides I’m doing.
Sure if I’d had a couple of grand lying about (or more) I’d be riding some very light deep section tubulars now but these would not necessarily be wheels that I’m happy to ride everyday over any road surface like I definitely am with the Cosmic Carbone SL.
I’m looking forward to getting more rides in so I can see if I still feel the same after another 500 or 1,000km on these wheels.
Thanks for reading.
If you’ve found this post useful, please consider subscribing to girodilento premium today to help us produce more great content. Subscribers also get access to our pro cycling coverage, premium interviews and the ability to give suggestions for future posts.
You can subscribe now for less than 10p per day by clicking on the green button below: