Aerodynamics
Aerodynamics
We’ve looked at how wider tyres perform and enhance rider comfort and control, but how about wind resistance?
Wider tyres require wider rims to perform at their maximum and the latest aerodynamic wheels have wider rims shaped more like a ‘U’ rather than a ‘V’ to create a curved profile. Air turbulence is less and makes the bike easier to handle in crosswinds.
If you start to run wider tyres on a narrow rim, say 19mm, the bulbous profile will be detrimental to aerodynamic performance, may adversely affect handling and could counter-act any marginal gain in rolling resistance. Wider tyres work best when fitted to wider rims, in the region of 23mm, to create a sleek and effective profile, and it’s little surprise that the move to wider tyres in the pro peloton has gone hand-in-hand with the trend for wider rims.
Other than a little gain in weight over a narrower tyre, the transition to a 25mm tyre seems to have little in the way of negative performance, although it might hit the wallet quite hard if you also want to upgrade to wider rims.
Conclusion
We will always be influenced to a certain degree by WorldTour riders and teams, and although tyre selection is often a personal choice, we can’t help but be swayed a little by the latest science and technology; especially if the conclusions are quick stark. We want to believe what we see and read, and if it works for the pros, it must work for us, right?
The big up-shot for the majority of riders running wider tyres is that a 25mm tyre experiences less rolling resistance than a 23mm tyre at the same air pressure and therefore requires less energy to propel the bike forwards.
Drop the air pressure in a wider tyre, as you’d be advised to do so, and you’ll improve comfort and handling, without adversely affecting performance. Given all these factors from the labs and the pros, it looks like a win-win situation for the average club rider who wants to improve performance and raise comfort levels.
What’s there not to like?