These days aero is everything. Once, they were just special race-day wheels of the elite riders. Today, deep carbon aero wheels are far more mainstream. From cyclocross to sportives and general riding, we seemingly can’t get enough of the deep, fast hoops.
Aero road wheels can be the best way to buy more speed, drop weight and add stiffness to your bike. Depending on what type of riding you do, picking the right aero wheel can transform your riding experience.
In the UK in the early 90’s, aero wheels began to find their way from triathlon and time trialling into road racing. At this stage, carbon wheels were comparatively expensive. Traditional, aluminium component manufacturers, such as Mavic and Campagnolo, released deep section aluminium wheels – these were aero, but very heavy, compared to specialist carbon manufacturers offerings such as those from F.I.R. and Corima. The early flat-sided, deep V section wheels were fast and lightweight. The 90’s saw a wide range of carbon spoked wheels at this too, such as the Aerospoke, Specialized 3 spoke, Mavic 3G, Corima 4 spoke and the Spinergy RevX (below).
User Friendly Unit Shifter
Although they were fast and lightweight, early spoked, deep section wheels could be tricky in less than perfect conditions, unless the rider was experienced. During more recent times, rim manufacturers have endeavoured to make rims that aren’t as badly effected by cross winds. Perhaps they realised that when leisure riders watched the pro’s in the Tour De France and wanted those wheels, they needed to be easily ridden by everyone in all conditions to maximise their potential market. The move started then towards more of a ‘U’ profile rim shape with a range of profile heights. Shallower rims are usually effected less by cross winds, deeper rims can be faster in calm conditions.
Wider, Smoother & Faster
The evolution in user friendly aero rim design happened while the boffins in the tyre companies realised that wider rim and tyre combination were faster and could offer more grip. Bikes featuring rims around 20mm width were the standard for a long time, allowing tyres to remain largely around 20 – 23mm wide. The move to wider 23 – 26mm width rims, together with far more 25mm + tyres has led to faster, grippier and stronger wheel and tyre combinations A prime example of the latest technologies in wheel design is the Forza Cirrus R45 wheelset, found on one of the fastest aero bikes in the world, the Ridley Noah Fast.
Several manufacturers have gone about producing carbon rims in different ways. Hed, Mavic and others, produced traditional alloy rims with light carbon fairing to provide the rim depth, retaining the traditional braking on aluminium. Others have always gone the full carbon route, some hollow, some filled with a hard foam core. However the end results are relatively similar – fast, strong and light wheels.
Here’s a few points to guide you through the key elements to look for when choosing an aero wheel set.
Rim depth is broadly speaking a trade off between weight and flat speed.
Shallow 25 – 40mm Can be lighter, great for hill climbing and accelerating.
Mid depth 40 – 60mm – Is often the best all-round option – relatively light for climbing, whilst still fast on the flat – best of both worlds.
Deep 60mm + Wheels can be faster on flat terrain where there is no repetitive accelerations, can be very stiff and a harsher ride.
Braking surface – A full carbon rim requires a special compound brake pad for the rim – both to protect the rim and improve braking.
Spoke Count – Generally carbon spoked wheels have between 16 and 24 spokes – usually more in the rear wheel. More spokes can add strength to the wheel.
Nipples – Hidden spoke nipples can make for a more aero wheel. However, these can be trickier to maintain – even requiring the removal the tyre and rim tapes for truing, for example.
Tub, Clincher or Tubeless?
The Ideal tyre choice for aero wheels largely depends on what the wheels are going to be used for.
Clinchers rims can be easy to live with and practical. A good reliable option for those who just want to get on and ride.
Tubular rims are lighter (no need for the hook around the rim edge) , however tyres can be a pain to replace and repair. Tubular tyres are stuck to the rim with special glue. Getting a tubular to sit flat and level on the rim also takes skill and experience.
Tubeless rims although similar to clinchers, they can offer a lighter combination because tubeless tyres work without inner tubes. Tyre sealant, used to fit and seal tyres can ‘self heal’ punctures too. Tubeless can be tricky to set up, depending on tyre and rim choice.
Will they work in your bike? Make sure your components match (Shimano/Sram or Campagnolo freehub body). Are they standard quick release or thru axle? Planning on upgrading your bike to discs in the future? These questions are all worth considering before making a costly upgrade.
Which aero wheels should you buy?
Regular riders will feel the benefit of a mid section aero rim as they feel the aerodynamic properties, noticeable over 30KPH. Clinchers are fit-and-forget, punctures are a simple matter of an inner tube swap. Modern clincher tyres are great. Tubeless can be equally easy to live with once set up and offer the bonus of self-healing some types of puncture.
Racers – Mid section wheels offer the best all-round option for a racer on a budget who races over varying terrain. Flat and fast courses (time trial and road) might be better tackled on deeper wheels. In an ideal world two sets of race wheels would cover most events. If you race on rougher roads, stick to clincher or tubeless. If money is no object and you have skills to fit tubular tyres well (or a great mechanic!), then go for tubulars.
Merlin Top Picks (March 2019)
Token C28 Zenith Carbon Clincher Wheels £769
Forza Cirrus Pro R45 Carbon Clincher Wheels £999
Shimano Dura Ace C40 Carbon Clincher Wheels £1099
Fulcrum Racing Speed XLR50 Carbon Tubular Wheels £1299
Enve 4.5 SES NBT Chris King Hubs £2635
See our Full range of Deep Carbon Wheels here.