November 11/09 16:13 pm - Shimano Dura Ace 7850 C50 Clinchers

Posted by Editoress on 11/11/09
 

Over the past couple of years we've seen the sales of aero wheels continue to rise.  More and more manufacturers are coming to the table with some good and some “not so good” products.  What is it that is so intriguing about deep-dish carbon wheels?  Could it be that more people are racing road bikes and are in need of a fast pair wheels? Partly, but it could also mean that more people are simply riding racing style road bikes and looking for the performance advantage of aero wheels. Shimano has created the Dura Ace 7850 C50 carbon clincher wheels to appeal to both the racer set as well as cyclists who are looking for a pair of fast wheels to supe up their road bikes.  Is it possible to have the best of both worlds…a wheel that can double as a race day wheel and also an everyday go-fast durable wheelset?

A pair of Dura Ace WH7850 C50 Clinchers

To answer my own questions, I've been testing a pair of the Shimano Dura Ace C50 carbon clinchers for the past few months.  It's well known that deep dish carbon wheels are ideal racing wheels.  My test was more of an attempt to figure out whether a wheel like the C50 actually has a place outside of the bike racing realm.  What I've concluded is A) the wheels are fast…really fast!  B) they are extremely durable for an all carbon racing wheel and C) being clinchers, they are more convenient to use more often than would be a pair of tubulars.  These are the exact traits I would look for in any pair of wheels whether I was racing my bike or if I just wanted to improve performance on my local club rides.

What makes these wheels so quick? To start, the rim itself is 50mm deep.  Can you say aerodynamic!  When up to speed, a rim this aero cuts through the wind and feels likes it's pulling you along.  The rims are made completely from carbon fibre and have offset spoke hole drillings.  This not only increases the rigidity of the wheel, but it also balances out the spoke tension between the drive and non-drive sides.  The rims and hubs are joined using straight pull butted bladed spokes (16 front and 20 rear).  The hubs are standard Dura Ace, complete with a titanium fast-engagement freehub body and oversized aluminum axles.  Dura Ace hubs are known for their reliability and how smoothly they spin, and these hubs did not disappoint. They remained tight and smooth throughout the entire test period.  Lastly, Shimano also opted for a laminated aluminum braking track for all of their carbon clinchers - a wise decision.  Anyone who has experienced the smell of heated carbon rims and melting brake pads, the less than stellar braking in wet condition, and the noticeable brake fade on long down hills will appreciate most what the aluminum braking surface means - smooth and consistent stopping power in all situations.

Hubs that will Spin Forever

Ti Freehub and oversized axle

My intent was to put the C50's through their paces to see how they stood up over time.  Could these wheels hold up to the abuse of being ridden all the time? Being clinchers, could they double as a wheelset for everyday use? I logged mile after mile with the C50's on my regular routes, which include flat roads, rail trails, gravel and dirt roads, through the mountains, and in the rain.  I'm typically not abusive on my equipment but I didn't go out of my way to baby the C50's. I used them as I would any pair of bike wheels.  And after months of riding they are still dead straight, round, and spinning smoothly - just what I would expect from a pair of expensive carbon wheels.

The Ride

On the road, the wheels' lateral stiffness and high spoke tension was obvious as there was no noticeable flex when pushing hard and no spoke wind-up - a must-have characteristic for a stable and solid wheel. Also, with a 50mm deep rim comes an inherent vertical stiffness. Some may find the ride harsh (I was using 23mm Vittoria Corsa Evo tires), but these wheels were designed for racing where most of the time performance wins over comfort.

50mm deep rims will pull you along

It's obvious that a 50mm deep cross section will make any bike feel fast at speed,  but what also adds to how fast the C50's really are is their weight.  Not groundbreakingly light (760g front, 960g rear), but once up to speed (~30km/h), the wheels' inertia pulls you along.  For example, on flatter roads, when using the same amount of effort, I was able to use a gear or two higher when compared to my regular box section wheels. On all but the longest and steepest of climbs (Sydenham, Rattlesnake, Ventoux) is their weight noticeable - hardly a burden unless you are climbing most of the time.  One thing I must also note, because of the deep cross section, riding in the wind will require a bit more concentration as wind gusts can throw you off your line.  This is characteristic of all aero wheels, so be aware, especially when riding with no hands or in groups.

Who needs these wheels?

For racing, one can only benefit by adding deep section wheels to their wheel quiver.  Not only are they an ideal wheel for flat-ish courses, but they are ideal for criteriums where sprinting out of corners is de rigueur.  On top of that they can also double as a great pair of time trial wheels, as a 50mm deep rim coupled with a narrow tire is a very slick TT set-up.

Gluing and maintaining tubulars is all but voodoo these days -a job often left to the race mechanic as it's tedious, somewhat messy, and very time consuming.  With wheel manufacturers like Shimano finally offering high performance and high quality carbon clincher racing wheels (that don't weigh a ton), there is no reason for the recreational rider, with an appreciation for the finer things, to shy away from 'racing only' equipment anymore.

With many high-end wheelsets being application specific these days - sub1000g wheels for climbing, mid v-section carbon wheels for general road racing, and deep v-section wheels for time trials - is there one wheel that does it all? The short answer is simply 'no', but someone looking for a wheel of uncompromised quality in a spare-no-expense, strong, fast pair of wheels should definitely consider the C50's.  Aside from making your wallet considerably lighter, these wheels will automatically make you faster; either on the race course, your midweek TT, or your weekend group ride.

The Dura Ace 7850 C50 clinchers retail for $2429.99CDN.  Included with the wheels are a pair of Dura Ace skewers, wheel bags, spoke tools, and valve extenders.  Similar to the rest of the Dura Ace line, the C50's are backed by a 3 year warranty should something go wrong.  Shimano wheels can be purchased through your local Shimano retailer and are available for 2010.  More information can be found at bike.shimano.com.

Review and photos by Chad Grochowina