The Truth About Tyres

In this episode of Fitter Radio, the conversation revolved around a critical but often overlooked aspect of cycling: tyre selection. Proper tyre choice can lead to substantial performance gains. Let's dive into the key points discussed.

One of the focal points was 'rolling resistance,' which is defined by the flexibility of the tyre system. It's crucial to choose tyres that perform well in real-world tests rather than just relying on the marketing claims of ‘high thread count’ or ‘advanced rubber compounds’. Different brands approach flexibility differently, affecting both performance and durability.

A significant discussion point was the discrepancy between laboratory testing and real-world performance. Most tyre tests are performed on smooth drums, not replicating the rough road surfaces cyclists commonly face. Factoring in real-world data to adjust lab results makes predictions more accurate, especially for challenging events like an IRONMAN.

Historically, cyclists believed that higher tyre pressure reduced rolling resistance by lessening the tyre's contact with the road. Recent studies however indicate that this leads to a harsher ride and higher rolling resistance on rough surfaces. Modern wisdom now suggests that slightly lower pressure can improve performance, comfort and reduce the risk of punctures.

Another key point was the relationship between tyre width and aerodynamics. Whilst wider tyres generally offer better grip and lower rolling resistance, they don't always enhance aerodynamics. The ideal tyre choice depends significantly on individual preferences and the specific conditions of the course.

The potential gains from choosing the right tyres are immense. For example, switching from a slower tyre to a high-performance one can save up to 20 minutes in an IRONMAN event. This improvement is far more significant than typical gains from upgrading frames or wheels.

Here are some actionable tips for athletes:

1. Test your tyres before race day.

2. Understand the trade-offs between performance and durability.

3. Be meticulous in preparing tyres by checking for embedded debris.

4. Use online calculators for data-driven decisions on tyre selection and pressure

In conclusion, making informed tyre choices can lead to significant performance improvements. Before you invest big bucks in upgrading your bike, consider the relatively small investment in high-quality tyres for massive gains. Stay tuned for more insightful segments from Fitter Radio, and happy cycling!

Bevan McKinnon / January 2025

Chris Collyer