Easton EC90 SL

The carbon fiber clincher is a problem child. It shows flashes of brilliance, can be faster than a power outage and melts down under high stress or when taken out of its preferred environment. The reality is that for most riders in the U.S. they work fine under most circumstances.

But if you live on the west side of Los Angeles, or anywhere near the Santa Monica Mountains, then you know at least two riders who have melted a set of carbon clinchers. The problem has to do with the crazy, winding nature of the roads that tumble down the canyons to the ocean. They’ve got all the ordered predictability of a schizophrenic’s one-sided conversation. And they are steep as Ferrari prices. That’s not necessarily a bad combination, but what it means is when descending those roads you brake frequently and forcefully. Heat buildup is a given.

And there a bunch of cooks scattering from this kitchen.

I won’t go into whose wheels I’ve destroyed, but I can say I’ve personally seen wheels from Reynolds, Enve, Bontrager and—gasp—Lightweight, all delaminated on descents. Typically, what I see is the brake track melt at one point and air pressure push that portion of the brake track out. I’ve never seen a Zipp wheel fail there, nor have I seen a set of Easton carbon clinchers fail in that way. The issue here is entirely heat buildup. Easton’s approach is a bit different from its competitors. Based on what I’ve learned from engineers I’ve spoken to, Reynolds, Enve and Bontrager all use resins (possibly the very same one) that cures in the 300 to 325-degree range (Fahrenheit). Lighweight is using a resin that cures at a temperature slightly above 350 degrees F. Easton has gone an entirely different route. The brake track on the Easton carbon clinchers (no matter which model you talk about) receives a ThermaTec coating which insulates the brake track from heat. I’m told it insulates the rim up to temperatures of 500 degrees.

Let’s back up a second. I’ve mentioned six wheels by name. I know there are more carbon clinchers on the market than that, but these are the six I generally see on the road and, more important, the ones I’ve been able to learn something about. To their credit, I’ve heard that both Reynolds and Enve have been really terrific about warrantying their product.

Easton’s approach with the ThermaTec coating is a novel approach in the bike biz. I haven’t run across another wheel taking quite this approach. Practically speaking, the braking experience is a bit different. The surface is banana peel slick. The first time I hit the brakes on my way downhill I immediately noticed slightly reduced braking power. It’s something I got used to pretty quickly though. The other thing you notice when riding these wheels is that the pulsing feel you get under braking with most carbon fiber wheels because one section of the brake track is just a little grabby, like the one sticky spot on a counter as you wipe it off, well that feeling doesn’t happen with the EC90 SLs. These wheels offer the most consistent brake response of any carbon wheels I’ve ridden, but they do require just a bit more braking force than with an aluminum rim.

I’ve taken these wheels down the two most notorious descents in the Santa Monicas, Tuna and Las Flores. Not a single issue. That said, because this is a coating and not a different resin used throughout the wheel, I suspect it is very important that you make sure the brake pads contact only the ThermaTec surface. An improperly adjusted brake pad might result in an expensive headache.

The EC90 SLs feature a 38mm-deep rim. This is the shallowest carbon rim Easton currently offers. It’s enough to offer some aerodynamic advantage once your speed is above about 28 mph, but it is still shallow enough that it doesn’t get pushed around a lot in crosswinds. The rim width is 20.5mm, the same as many other existing Easton rims. I’ve become enamored of some of the winder rims out there that give tires a bigger footprint and would be willing to accept a slight weight penalty to get that. Speaking of weight, Easton says these run 1530g. My scale agreed—1528g. To get there they use 18 spokes front and 24 spokes rear. The front are laced radially while the rear are 2-cross on the drive side and radial on the non-drive side. All the nipples are alloy.

I’m told that impact resistance was one of Easton’s big issues in building these wheels, that they wanted unassailable impact resistance. I’m told these carbon rims are more impact resistant than their aluminum rims. These are no wilting lilies. The rear wheel is available with either a Campagnolo or Shimano freehub body. And if, like me, you have a bit of everything, changing out the freehub body from one type to another, the operation is easier than pumping gas.

In my previous review of the EA90 SLX wheels, several readers wrote in to report their troubles with the bearings in Easton wheels. My EC90 SLs came with ceramic bearings; I’ve not had a bit of trouble with them and these, in theory, should be a bit more finicky than the steel bearings found in my previous wheels. They’ve been flawless in operation and they turn as fast as tables at a McDonald’s.

One thing you’ll notice in Easton’s product description is the phrase “acoustically tuned.” What that means in bike speak is that Easton trues their wheels with the aid of transducers. A transducer is a kind of microphone. The wheel builder—yes, all of Easton’s carbon wheels are built by hand—will pluck each spoke as he tensions and trues the wheel. Think guitar string. Once plucked, the tension on the spoke will determine what pitch the spoke vibrates. If all the spokes have equal tension, a true rim will run straight.

Easton sells the wheels alone or in pairs. The front goes for $850—the cost of many high-zoot wheelsets, while the rear goes for $1250. Given what some of their competitors’ wheels go for, this seems reasonable. I won’t call it a great deal, but I believe the value is there because of the level of confidence I have that I’ll get home with both wheels intact following a big descent. Riding home with your rear brake opened up to keep the pads from rubbing the bulging brake track and worrying with each bump that the bead will blow off the rim makes for a really stressful 20-mile return trip. “Blows” would be the technical term.

My general feeling has been that if you can’t ride a product anywhere you would ride your traditional equipment, it’s not ready for prime time. I’m not talking putting a 100g road stem on a downhill bike. I mean that a product intended for the road should work anywhere road bikes are expected to be ridden. Some of the companies offering carbon fiber clincher wheels (and honestly, this applies to some of the tubular wheels as well) are playing fast and loose with people’s safety in my opinion. It’s not many people as I expect there are only a thousand or so cyclists who regularly ride in the Santa Monica Mountains. But everyone I know who owns a set of carbon clinchers has a story of melting one or more wheels. On the other side, I’ve got a buddy, a big guy who likes German technology, who has stopped as many as three times on the way down a descent just to make sure he didn’t kill his wheels. I have to ask, what’s the point?

I can’t help but wonder what circumstances could bring riders problems elsewhere. There are some twisty, steep descents in New England. And I’ve raced some short, tight crit courses that required lots of braking. If there’s a chance that a wheel won’t survive under reasonable use, should it really be on the market?

We’ve got a ways to go, I think. Easton, at least, has given this some thought and devoted some of its considerable technology to addressing the problem. These are terrific wheels.

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  1. Cam

    I generally agree the EC90SL’s are great wheels, having ridden a pair extensively for 12 months in all conditions.

    My wheels pulse slightly, but not nearly as much as cheaper ODM (third-party branded) wheels. The lack of braking power (with the supplied Swiss Stop pads) on wet descents warrants caution – compared to a machined aluminium sidewall.

    The R4SL freehubs are superior to the last generation, which regularly failed. Changing the freehub body is, as you mentioned is child’s play via two 5mm hex keys.

    The EC90SL clinchers that I own have only been trued once in the last year. Given they have also been on dozens of international flights during that time (my frame was cracked under compression whilst in the same bike bag as the wheels), their robust build is noteworthy.

    Actually, I never traveled with expensive carbon wheels prior to owning EC90SL’s, due to concern over perceived fragility and application limitations (when tubular was the only standard available in a full carbon rim). Now I don’t even think twice about which wheels to choose before jetting off.

    I’ve had no production-based issues with my wheels, but personally saw a pile of MY2011 EC90SL clincher wheels whose rims had failed (either blown/warped sidewall, or cracked rim at spoke port) at an Asia-based warehouse in August of this year. Apparently, a batch-related issue…

    P.S. Unless something has changed, the statement “The EC90 SLs feature a 38mm-deep rim. This is the shallowest carbon rim Easton currently offers. ” is not correct. Easton make a 24mm EC90SLX – the favourite wheel of Cadel Evans which Easton would have canned last year if he didn’t like it so much. (Easton’s North America rep mentioned that to me at Eurobike this year.)

    P.P.S oh, and these wheels can be purchased almost anywhere online for sometimes half the MSRP, thanks to Easton’s loose supply chains.

    P.P.S I understand if you edit the last two bits

    1. Author

      All: Thanks for sharing your experience.

      Cam: I should have clarified that the 38mm-deep rim is the shallowest carbon clincher rim. The SLXs are tubies and as a result, different in my mind. Interesting about the failed rims you saw. I’d be curious to know the full story. I’m aware that Easton, like many manufacturers, will make running changes to product and it would be interesting to know if those rims were indeed a bad batch or prior to a running change.

      An interesting aside regarding the Eastons is how they test them: Big guy, 50-lb. backpack, standard Ultegra pads, not Swiss Stop.

      I think I’m going to let readers update us on where they see good pricing in the future. Not everyone (“everyone” being defined as the folks with the company whose product I’m reviewing) has been thrilled when I report what I’ve seen on the web. Price parity results in better service to the consumer; it’s up to the manufacturers to pursue it.

  2. Florian Goessmann

    A few observations after riding the EC90 SL myself on a day to day basis for about 12500km now:
    – I have melted one rim (rear wheel). Steep descent on a very hot day. I think it was a construction rather than design fault and Easton replaced the entire wheel with no hassle.
    – The bearings are the weakest link: Front wheel bearings preload had to be adjust after almost every ride with only 3000km in total done on them. The bearings of the first rear wheel fared a little better and only started to behave like that after about 6000km. The bearings on the replacement rear wheel I got where dead on arrival! I since replaced all bearings with industrial stainless steel ones and have had no issues since. Preload stays set and rolls smooth. The original bearings never ran smooth but ‘crunchy’.
    – Breaking is good, even in the wet
    – Even strong cross winds are manageable


  3. Champs

    Yet I’d rather have a disc-specific rim and be done with it. So long as rim wear, brake fade, pad materials, and the grating sound of pads on carbon are distant memories, I’ll cope with a few non-rotating grams. I *love* the mechanical front disc on my Litespeed commuter so much more than cantis, and the

    even if the weight savings and possible aero edge of a rim without brake tracks is just an illusion. What I know for sure is that ENVE 29er rims

  4. Champs

    Wow, my phone completely botched that. TLDR: cut the rim brake BS, give me disc brakes. There are more pros than cons, even if you take out promising-but-not-proven advantages.

  5. Sam

    Glad to see someone on your side of things naming names and taking some carbon wheel manufacturers to task for building products that regularly fail at performing their intended duties.

    I’ve always found it mind boggling that durability ceases to be of importance at the highest price point, but thus is the way of innovation–faster and lighter seem to best stronger more often than not.

    As a cyclist who rides roads of all sorts in all conditions, I am extremely reluctant to invest in a set of full-Carbon wheels, though at 6’3″ and 155lbs wet, I suppose I’d do ok. Good thing my lack of funds makes it a non-issue for the moment.

  6. mark

    I’ve seen a set of EC90SL tubulars survive a head-on impact with a shed at ~50kph. They were slightly out of true but structurally intact afterwards. Can’t ask for much more than that in the way of impact resistance.

    I find it ironic that Easton has internal nipples on their tubulars but external nipples on their clinchers. The other way around would make more sense. Regluing a tubular just to true the wheel is a major PITA, whereas remounting a clincher is no big deal. That said, my EC90 aeros haven’t needed to be trued, but we’ll see if that changes when I race cross on them next season.

    1. Author

      Mark: That’s quite the testimonial. I wouldn’t trust any of my aluminum rims to survive that. I mean, I’d be grateful if they did, but holding my breath wouldn’t be my first course of action. And ditto on the hidden nipples on the tubies. There’s not a scenario where that makes sense.

  7. Wayne

    “My general feeling has been that if you can’t ride a product anywhere you would ride your traditional equipment, it’s not ready for prime time.”

    Well said.


  8. noel

    I think you’re referencing a set of Reynolds I melted and warrantied. I should say that i raced 2 full seasons of two or three categories a weekend 2’s or 3’s… hundreds of races on those things, a couple of years of 15-20 hour a week training rides… and then all the riding post-racing and two full rides from norcal to socal down the whole coast by the time i melted a rim over-breaking down Tuna. I only trued them once after a last lap crash at Manhattan Beach. No servicing. I just now changed out the spokes…So for me… I think they’re the most durable wheel i’d ever used.
    I’d also say Tony destroyed the braking surface on his Eastons within weeks, warrantied them and then resold them after the hub got wonky. Same goes for Greg.
    Its always tough to abstract and generalize off of one set of wheels… but…. I’ve got 3 sets of Reynolds… and while having to mind the braking on technical descents is a nuisance… I can’t think of a carbon clincher that doesn’t require letting the wheels roll to avoid melting out the resin.

    1. Author

      Noel: If your set had been the only ones, I wouldn’t have mentioned it. Reynolds are one of several sets I’ve killed. Your use of them points out how great this stuff is 90 percent of the time, but they really haven’t been standing up under descending for lots of people. I think the fact that they work so well in most circumstances leaves people think they will work well in all circumstances, and that’s just not the case. As to your point about needing to let a carbon clincher roll on a descent to avoid melting the resin, Zipp is literally the only manufacturer I haven’t heard of having a descending failure. That’s not favoritism on my part; I think it has to do with them using a resin with a much higher (roughly 700 degrees) cure temperature.

  9. noel


    Loan me yours for January? Imma need to unselfconsciously brake down Tuna and bring the funback into life for 2012.. and it’s on you to make that happen. Otherwise… it’s a life of Fernwood and ridicule.


    1. Author

      Noel: If loaning a set of wheels is what it takes to get you down Tuna instead of Fernwood … done. You can still ridicule me, though.

  10. Dave

    I saw a guy melt a Zipp 404 descending down the mountain to the start of the last stage of Killington Stage Race this year. Happened pretty much right in front of me.

  11. Noel L

    Let me be another one to add to the list of melted rear wheels. Easton replaced the entire wheel without hassle, but I’ve since sold the set.

    I too believe that anything on my bike should be rideable 100% of the time. Carbon clinchers aren’t there yet.

  12. Tom V

    Here’s a novel idea. How about riding the Santa Monica mountains on a standard box section pair of alloy clinchers instead of trying to pose like a pro on a 45mm deep carbon clincher which does very litle to actually make you go faster??? Using carbon clinchers fora recreational ride is the definition of poser and stupid combined. It amazes me how many cyclist attempt to look like UCI eurotrash pros while putting out 300 watts max sustained. LOL

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  14. antonio

    seeking some suggestion on EASTON EC90 SL – I recently purchased a pair and have about less than 800,mi. on them and my rear finally failed.
    I read and did my research prior to my purchase and took a chance hoping this would not happen but surprisingly it did! It happened on a long descend, steep and with several switchbacks & turns. Through it I heard the ‘humping” sound I I knew it immediately as it was very obvious the rim-wall was un-even.
    being aware of this potential, I always feathered & alternated my braking cautiously but much to my surprise they failed.
    I really hope Easton may provide me with a new pair?
    Anyone have experience with returns? I no longer have the purchase receipt but the wheels are practically new!
    Would appreciate responses.
    Thank you.

    1. Author

      Antonio: My knowledge of others’ experiences with issues with their wheels is that they are really responsive. You can reach them here.

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