Knowledge Level: Intermediate
Of all the components on your bike that can affect its performance and handling, wheels potentially have the greatest impact. Unfortunately, if you’ve bought an off the peg bike, the wheels are often where manufacturers will look to save money and are often under specced relative to the rest of the build.
A new set of wheels can genuinely transform your bike but what should you opt for and how much should you spend?
Do some research about your existing wheels and it’ll give you an idea of their quality. It might surprise you to know that even on a £2K plus bike, it’s not uncommon to find wheels that would retail for as little as £150. Upgrading these to a quality alloy wheelset costing between £500-£700 will make a noticeable difference. Increase your spend to up to £1000 and you’ll open up the options of carbon, enhanced aerodynamics and lower weight. As with all cycling components, if you’re budget is unlimited then you’d be able to spend a lot of money. A top end deep section carbon tubular front wheel and matching disc for the rear, that’d grace a Tour de France time trial, would set you back upwards of £3000.
When buying a new set of wheels, it’s important to factor in the type of rider you are, the sort of riding you tend to do and the roads you usually ride on. Many high end carbon wheels have an upper weight limit, so won’t be suitable for bigger or more powerful riders. If you like hilly sportives or are heading to the Alps or Pyrenees, then weight and braking performance could be more of a priority than aerodynamics.
If you’re targeting time trials or triathlons, deeper section more aerodynamic wheels would probably serve you better. Will you be doing all of your training on your new wheels or saving them just for racing or special rides? If it’s the former, you might want to consider slightly more robust all-rounders rather than an out and out no compromise racers.
Clinchers, tubs and tubeless
For general riding, training and sportives, clinchers are probably the sensible choice. Changing an inner tube is easy if you puncture, there’s no messy glueing or taping involved and, for ride quality and weight, you pay little or no cost with modern clincher tyres.
For circuit racing, time trials, triathlon and track many riders still favour tubular tyres. The main reasons are marginal gains in rolling resistance and a claimed better ride feel and quality. As a tubular rim doesn’t have to withstand the pressure of an inflated inner tube inside it, tubular wheelsets are often also significantly lighter.
For longer races and rides, you’d have to carry a spare tubular, wrestling one off at the roadside can be a battle and, as it won’t be properly taped or glued, you have to corner very carefully on the replacement. Using sealant as a preventative or carrying a combined sealant and inflation device is another option that does improve the practicality and reliability of tubulars.
Tubeless tyres offer a third option that give some of the weight and handling benefits of tubulars with the practicality of clinchers. Setting them up can be tricky and, with the sealant, a bit messy but they ride well, eliminate the risk of pinch flats and penetration flats usually seal instantly. If you do get a flat that doesn’t seal, you can just put a tube in. More manufacturers are embracing tubeless road wheels but choices of rims and tyres are still fairly limited.
Handbuilt vs machine built
The main advantage of going to a specialist wheel-builder is that they will be able to advice you on exactly the right combination of rim, hub and spokes to suit you and your riding. There’s also a degree of reassurance that you’ll be speaking to and forming a relationship with the person who’s building your wheels and that they’ll do a good job. Most good wheel-builders will guarantee their work and some even offer a truing for life service.
Many larger manufacturers also hand-build their wheels and, if this is the case, it’ll be proudly and prominently stated on their website. Again, look into warranty options and damage protection plans that some offer as, especially if you race on the wheels, they can be well worth considering.
There’s nothing wrong with machine built wheels and some of the best performing wheelsets currently available are now manufactured this way. Extended warranties and protection plans are often options and the build quality should not be inferior to hand-built. Occasionally with machine built wheels you’ll get a few plinks as the spokes bed in, as they won’t have been pre-stressed in the same way hand-built wheels are but this isn’t a problem.
Weight vs aero
Until fairly recently weight was king in cycling and shaving grams wherever possible was thought to be the key to optimal performance. However, and evident from the deeper rims you see in the pro Peloton, the drive now is more towards improved aerodynamics. On all but the most mountainous terrain, aero will trump weight every time. Obviously, with modern materials such as carbon fibre, it’s possible to have lightweight and aerodynamic but you’ll certainly pay financially for the privilege.
Braking on a standard alloy rim is excellent and, even with fairly low end calipers, can always be significantly improved with a pad upgrade. Unfortunately, although significantly better than in the days of cork pads, braking on carbon can occasionally be unpredictable. Pads are improving rapidly but heat dissipation and performance in the wet is still not as good as alloy.
On long mountain descents, if you are heavy on your brakes or tend to drag them, heat build up can be a real problem, especially with carbon clincher rims, and can lead to blowouts. Some carbon rims do have alloy braking tracks fitted and, although adding some weight to the wheelset, this is a very sensible compromise.
It’s essential that you use the right pads for your wheelset, especially with carbon rims. Most manufacturers will supply pads that they recommend you to use and, failure to do so, will often invalidate warranties. Changing pads is imperative if you’re training on your old alloy wheels and occasionally swapping in your new carbon wheels. Even if your pads are a compound that can be used on both alloy and carbon, you should still have one set for the alloy rims and one for the carbon. The reason is that braking on the alloy rims will embed tiny shards of metal into the pads which can badly damage carbon rims.
Rim depth, profile and width
In general the deeper the rim, the greater the aerodynamic gains will be. The front wheel of a time trial setup may be as deep as 90 mm but, although this will slice through the air brilliantly, there are tradeoffs in handling, especially in crosswinds, acceleration and weight. A 40-50 mm rim depth offers a good balance for all round riding but even 20-30 mm deep rims can be profiled to offer aerodynamic gains. Rim profile is a key factor in how a wheel will handle and perform aerodynamically and, the deeper a rim is, the more of a factor profile becomes.
Older and cheaper deep section wheels will tend to have a fairly narrow and simple V-profile. These will perform well in stable head-on wind conditions but will be harder to handle and less efficient in cross winds. More expensive and modern deep section rims will have a bulging toroidal shape which wind tunnel testing has shown to be more effective and stable in variable wind conditions. There is also a trend towards wider rims which, slightly counterintuitively, can offer superior aerodynamics. If you are opting for wider rims, check that your frame can accommodate them and remember, if you’re swapping in your old wheels for training, you’ll need to adjust your calipers.
As spokes add weight and create air turbulence and therefore drag, the number of them is often significantly less than on a traditional box section alloy rim. A deep section rim will have a degree of inherent strength but, if you’re a heavier rider or tend to be hard on components, low spoke count wheels might not be suitable. Check manufacturers’ recommendations or, if you’re going to a specialist wheel-builder, listen to their recommendations.