MAVIC COSMIC SLR 45 & 65 disc review
Disclaimer: the wheels are sponsored however the views are my own, unfiltered and based on 12 months of honest use.
A long, long time ago, as a teenage rookie triathlete, my parents upgraded my 18-ton aluminium road bike with a set of Mavic Ksyrium SL rims (some die-hard cyclists out there might remember the famous red spoke and hub). I felt like the bee’s knees speeding up the climbs on my featherweight aluminium hoops and although I changed bikes regularly over the next 15 years or so, those incredible wheels stayed true.
Fast forward to 2022 and although I still have the red-spoked treasures, carbon rims and disc brakes have taken over. Yet in a funny twist of fate and what seems like a bit of a circle closing as I enter the last seasons of my career, I have been lucky enough to get support from none other than… Mavic.
I have been training and racing on two sets of wheels, the MAVIC Cosmic SLR 45 disc and MAVIC Cosmic SLR 65 disc for the last year. I have put them through their paces on a 47cm Trek Madone SLR road bike and an XS Orbea Ordu TT bike; the 45s have done about 9000km, the 65s around 2000 (any other bike training was indoors). Here are my impressions after 12 months on the road.
First things first, I’m no wheel expert: I’m a 55kg, female triathlete who often trains and races in the mountains.
I’m looking for a wheel that is reactive when I need to get up out of the saddle, that doesn’t mind getting knocked around on less-than-pristine roads, that won’t blow me off the road when it’s gusty and, last but not least, that I can get off the rim if I puncture.
So did the Cosmic SLRs deliver??
Handling and reliability
One of the biggest differences between Mavic and other wheel brands are the flat steel spokes and external nipples. Their Fore Carbon technology means the nipples screw into metallic inserts on the lower bridge of the carbon rim, leaving the higher bridge intact and thus adding stiffness and removing the need for rim tape (weight gained, less friction). The bulky spoke nipples might not the most aesthetic (and probably not the most aero either) but from a stiffness and reliability point of view I was pretty impressed.
My main training machine is the Trek Madone, which is pretty bulky for a little girl. The bike was in fact utterly listless with its original Bontrager hoops, but the Cosmic 45 SLRs completely transformed it. The wheels are reactive and easy to get moving on the climbs, smooth and fun, and efficient out of corners. I even have (relatively) fond memories of my VO2 max winter hill reps: despite their 45mm section, the wheels jump when I jump and when you’re a climber, that’s definitely what you’re looking for. They also hold speed well, both up the hills and on flatter sections.
As for the 65s, I put them on the Madone for a few flatter rides and both the bike and the wheels really came into their own. Fast and smooth, a joy to ride! Having said that, the 65s handled well uphill too. Though obviously a little less reactive that the shallower model, I didn’t particularly notice their weight.
I experienced much the same on the TT bike. The 45s made a bike that is a bit of a truck quite pleasant on hills and out of corners. The 65s are fast and steady on rolling courses and were my choice for all my Ironman races this year.
In the wind
With the flat spokes, I was a little worried about handling in crosswinds and on descents, especially as a smaller rider. As it turned out, crosswinds were absolutely no issue. I rode a 45 front/65 rear combo in proper gusts at IM Lanzarote and a 65 on the front at IM Israel in strong winds and didn’t think twice.
I had a few wobbly moments on breezy descents at higher speeds, mainly with the 65s when the front wheel caught the air, but nothing that wasn’t sorted by feathering the brakes a little.
Weight always seems to be a massive question but from experience it really isn’t in the real world for any effort that isn’t an all-out uphill QOM attempt. If anything ever felt heavy to me, it was the bikes rather than the wheels.
Official weights per set:
- 1470g for the SLR 45
- 1540g for the SLR 65
Sturdy does it
The 45s in particular were put through their paces on rough Andalusian roads all winter and pot-holed French roads all summer. Despite a few nasty noises when I hit larger bumps, they haven’t budged and are still perfectly true. I am admittedly not a heavy rider, but the wheels have surpassed my expectations in that regard.
I have heard of riders having issues with Mavic freewheels but with a max power under 1000w, that’s clearly not a problem I am likely to experience and I unfortunately can’t provide any input there. Both sets of wheels are still rolling like new.
To tube or not
Like many triathletes, one of my main worries is to puncture in a race and lose bucketloads of time struggling with a wheel while everyone else flies past. I have smaller hands that cannot manage without tyre levers, so being able to repair a puncture quickly and get back on the road is paramount.
These wheels are tubeless compatible with a hooked profile. (This adds a little weight but is apparently preferred by Mavic for safety, as most riders tend to use excessive tyre pressures and they don’t want to risk them bursting off.)
I rode the wheels all year with a classic tube setup. I know, friction of the inner tubes, weight and all that… But honestly, I just don’t want the whole mess of the sealant; I hate the way it gets everywhere, clogs up the valves, leaves a mess all over the road and bike if you do actually puncture. Wrestling a tight tubeless tyre off the rim is a job too, and one I don’t want to have to deal with during a race. So I prefer the ease of mind and use that tubes provide. (Don’t judge me.)
I use 25mm Conti 5000 tyres on both sets. I did actually struggle to get them off several times in training as the tolerances seemed to be very tight, but I finally figured out that by making sure both beads were properly unclipped and shoved into the rim bed all the way round (something I haven’t necessarily had to do with older, non-TL tyre-wheel combos), I could pop them out easily. In fact, Mavic have this exact procedure explained in their Youtube video.
Lesson of the day: always practice before the race (I have it down to 3’18 in my living room).
Aesthetics & sound
As someone who doesn’t really like SHOUTING, I really appreciate the soberness of the Cosmic design. Customisable stickers are available (and I probably should have used them for a little more brand visibility when racing) but to be honest I have been more than happy riding a classy, streamlined set of wheels with just a touch of yellow to remind me of Mavic’s cycling history. The large spoke nipples aren’t wow, but I can overlook that for the reliability they provide.
Sound-wise, if you’re looking for that sexy rear wheel buzz when you’re coasting, the Instant Drive 360 freewheel is disappointingly silent. Mavic however have a trick up their sleeve, as you can easily remove the silencer joint in the freewheel body by following the instructions in their Youtube video.
This review was actually supposed to be shorter but I got a little carried away, which is what usually happens on my bike anyway.
In a few words, I found both the Cosmic SLR 45 and 65 models to be reactive, smooth and reliable. The 65s are fast and fun. I rode the 45s for most of the season and from a versatility point of view I couldn’t have asked for a better option.
With this range of wheels, I don’t think Mavic was going for flash but rather for a versatile, high performance option that would go the time and distance. Quietly and efficiently, true to their history. And though there may be no red spoke anymore, that has been exactly my experience this year.
Any questions, drop me a message!
*A massive thank you to Guillaume Martin and the whole team at Mavic
**Detailed specs and wheel info can be found here: SLR 45 disc / SLR 65 disc