Now that 29ers are rapidly gaining acceptance, the list of aftermarket upgrades is really starting to increase, with wheels a particular area of increased development. We have just got our hands on Reynolds’ new 29er carbon fibre wheels, one of the first of a crop of new carbon wheelsets on the horizon.

Hot off the production line, it’s clear that Reynolds have put a lot into these new wheels. We’ve managed to squeeze in a first ride on them, and before we carry out some more testing, here’s a first look at what could make these wheels a must have upgrade for 29er riders. And further below, we’ve got an exclusive interview with Aaron Packard from Reynolds.

In the past couple of years the company has been readily adopted by road cyclists, with an extensive range of carbon wheelsets, but it hasn’t made quite the same impact with its mountain bike offerings. That’s set to change as they’ve invested loads of time into these updated 29er wheels, with major changes right across the wheel from rim to hub.

Each wheel is built by hand in the company’s own production facility, allowing extremely precise management of every step of the process, as well as ensuring quality control is right up there. They use continuous fibres of carbon, laid in place meticulously by hand, which creates a better structural finish.

At the rim Reynolds have widened it out to a 21mm internal width, while the depth is now 28mm. The extra width will give a better platform for tyres from 2in up to 2.3in, and prevent them rolling as they would on a narrower rim. Boosting the depth obviously adds more meat to give the tyres the desired durability and strength to shrug off aggressive riding.

The internal shape of the rim has been improved too, with new lip designed to give tubeless tyre beads a better seat and ensure a good airtight seal. As the photo shows the rim is supplied tubeless ready, but using a rim strip.

There’s no problems with compatibility, the hubs can be used with just about any axle standard currently doing the rounds. That means 9mm and 15mm bolt-thru for the front, and 135mm QR and 135mm/12mm thru-axle on the rear hub – you get a bag of axle caps with the wheels to set them up for you bike. 24 DT Revolution spokes front and rear lace the rims and hubs together in a 2-cross pattern. Weight is 1596g for the pair.

We say

2012 is the year of the 29er mountain bike and carbon wheelsets are set to be a big part of that rapid growth. Many manufacturers are adding carbon fibre 29er wheelsets to their line-ups, and these Reynolds tick all the boxes, offering a great value to performance ratio. We’ll have first ride impressions once we’ve ridden them some more.

Interview with Aaron Packard

Keen to know more about the development of these new wheels, we put a few questions under Aaron Packard’s nose, the Design Engineer at Reynolds.

Bikemagic: Can you tell us a little about the carbon fibre construction of the rims?

Aaron Packard: Without revealing any of our trade secrets or proprietary process, I can tell you that a lot of engineering goes into our rims. The rims are constructed out of a unidirectional prepreg which means that we can orient the fibers in the directions that make the most sense for a particular area of the rim. Consider for instance the channel of the rim. It needs to be able to handle not only the pressure from the tire but also tolerate localized impacts from rocks and other trail debris.

The sidewalls on the other hand are designed to take the loads from impact and transfer them across the rim’s cross sectional area. In addition, the sidewall has to provide stiffness and strength to the rim while carrying the shear stresses induced from braking.  There is a lot going on in a bicycle wheel when you are riding it and the challenges are to make sure that all of the variables are taken into account so that an accurate mathematical model can be constructed during the design phase.

BM: They’re specifically designed for mountain biking?

AP: Unlike some companies that will just take a standard road rim and market it as a 29er, we specifically designed our 29er for mountain biking. That’s why we started out with a blank sheet of paper when designing it.

We made a list of what characteristics we wanted to see in the wheel: stiffness, weight, strength, weight, durability, a profile that interfaces with the tire to provide a good contact patch while riding…

The list consisted of a full page of measurable requirements that we call our “50 questions”. After spending days creating multiple models of different 29er rim profiles, some of which I changed by only tenths of a millimeter, we settled on a profile that was a good blend of what we were looking for.

BM: Did you face any particular challenges making these new wheels?

AP: A concept that looks good on paper is one thing but how does it perform? That’s why we do a lot of testing. To make sure that we have a wheel that meets all of our design requirements we test all the components individually and then together as a system. For instance, we put the rims through a rigorous impact test that increases in severity until it fails. By analyzing the failure mode we can assure that the rims are not only robust but light weight.

BM: The rims are only part of the story, what’s the deal with the hubs?

AP: We also worked with our hub suppliers to develop a hub that meets the demands of racing, training, and general riding. No, they aren’t DT internals but after quite a bit of testing, they’ve taken everything that we’ve thrown at them.

BM: How much testing and development has gone into these wheels? Do you test them yourselves on rigs, or rely on real world testing for data and feedback?

AP: Lab testing is critical but by no means the whole story. Besides, you can design a test that makes almost anything look good. The real test is how the wheel performs under a rider in the real world and by real world I don’t mean a nice spin around the block.

During the development of the 29er we tested sets of wheels in the Cape Absa Epic in Africa, we had local pros hammer them into the ground, and we sent wheels to 24 hour races.

As you can imagine, that’s a lot of work that goes into a wheel and we wouldn’t be doing all this if we didn’t whole heatedly believe in the 29er. As a wheel company we’re here to support it.

BM: Do you see 29er as a big growth area for Reynolds?

AP: Not only do we expect to see the 29er continue to gain traction in the mountain bike market but it will be a jewel in the Reynolds product line for years to come.

£1499.99 from www.upgradebikes.co.uk | www.reynoldscycling.com