Carbon-fibre soles have become the norm for high-quality road bike shoes, but what benefits do they actually provide?
Just as having a carbon bike frame usually indicates a rider is quite serious about their cycling, carbon-soled shoes have likewise become a sign of dedication and aspiration. With prices of these shoes dropping well below £100, there seems little reason not to buy a pair. But are they always the best option?
As always, it’s a case of different strokes for different folks. Does performance rule all, or is comfort a factor for most, such as touring cyclists who need all-day comfort?
Many carbon-soled cycling shoes offer next to no comfort. They are designed first and foremost to offer a rigid pedalling platform, albeit with a certain degree of flex. Accurate fitting and supportive footbed construction improve on-the-bike comfort.
So what are the benefits of carbon soles? The first and most obvious is stiffness. Unlike other sole materials that flex more and therefore lose some of the energy that the rider puts into the pedals, carbon transfers the maximum amount of rider effort into pedalling force.
Do you need carbon-soled shoes?
For racers and serious cyclists, pedalling efficiency is paramount, obviously. However, for some road riders — especially new and leisure cyclists — non-carbon soles may have benefits, especially in terms of cost. Even at sub-£100 levels, carbon-soled may seem prohibitively expensive to riders taking their first tentative pedal turns on a road bike, so other options offer good performance and greater affordability.
When Cube launched its debut range of road shoes last year, it opted for a reinforced nylon sole (see ‘No’ box below), which it felt offered the best balance of performance and price.
“We think it is all about the target group of the shoes,” Cube’s shoe designer Norman Ebelt says. “For an average rider a reinforced nylon outsole is stiff enough.”
Even so, although Ebelt is happy with his resulting products, he acknowledges the benefits of carbon. “For a good amateur or professional rider, a carbon outsole makes definite sense and is very important for good power transmission.
“For our new road models, which we will launch at the Eurobike show later this year, we have specified carbon outsoles. Of course, the retail price of these shoes will be higher than for the nylon outsole shoes.”
It’s not just a case of direct, efficient power transmission; often, nylon or moulded plastic soles are significantly heavier than their carbon equivalents, so carbon offers a weight benefit, too. But — just as not all carbon bike frames are equal — not all carbon soles offer the same advantages.
“When considering good carbon soles, it’s worth noting not only the weight but the type of carbon used and the layering of the carbon, especially in the cleat area,” Clas Nordström, Shimano Europe’s category manager for cycling footwear says.
“And whether it’s carbon or a nylon material, shape is crucial. An ergonomically designed sole, such as Shimano’s unique Dynalast shape with toe and arch support uses bike biometrics to create a stable and supportive platform across the foot and throughout the whole of the pedal stroke. Finally, the range of positions for the cleat to sit in is also a good indicator of a better-soled shoe.”
To sum up, construction and performance aren’t enough without comfort, so choose wisely.
The benefits carbon soles offer in terms of power-transfer are significant and well worth the extra financial outlay, especially for competitive or challenge cyclists. Of course, if using your road shoes for a variety of tasks, including commuting, it’s worth looking at other options. More importantly, whatever sole type you opt for, consider comfort. There’s no point having efficient pedalling if the cost in terms of enjoyment is too great.
Yes: Clas Nordström, Shimano Europe category manager for cycling footwear
“If we talk about the benefits of carbon soles, it’s all about stiffness. Carbon soles allow for greater power transfer from the rider’s legs, through the sole to the pedal, crank and transmission. Conversely, the benefit of other options is comfort, albeit at the sacrifice of speed. The added benefit of carbon is that the shape remains true for an incredibly long time.”
No: Norman Ebelt, Cube’s shoe designer
“We launched our first shoe collection last year at Eurobike, and for us it was important to have well-equipped shoes for entry-level and amateur riders. These riders want to have very good performance for a good price. So, for our main target group for this first Cube shoe collection, a carbon outsole was too expensive. Instead, we used a good reinforced nylon outsole, which is stiff enough for entry-level and amateur riders.”