Interview – V Sivaramakrishnan, Chief Technology Officer, TVS Srichakra Limited | Basic Questions About Tyres Answered

Since there is a lot of misinformation about tyres floating around the Internet, we presented a few simple questions to V Sivaramakrishnan, Chief Technology Officer, TVS Srichakra Limited, and here are the answers.

Who decides the recommended tyre pressures for a motorcycle? What is the process?

It is purely the original equipment manufacturer (OEM) who decides the tyre pressure for a particular motorcycle and this decision is made in consultation with the tyre manufacturer. During the development process of a motorcycle, the tyres have to be homologated to the bike because you have different loads, including front axle load, rear axle load, single rider, and with a pillion rider. Based on our calculations, we recommend the tyre pressures to the OEM and we give a band in which they may operate. Based on their tyre tuning and the vehicle’s suspension tuning, they are free to choose the pressure within that band.

When finding recommended pressure, is there a certain weight category that the rider falls into?

Typically, all tyre pressures are recommended for the maximum Gross Vehicle Weight range of the vehicle which is two riders put together at a specified weight of about 75-80 kilograms per person; 160 kg is the payload on which all the weights are calculated along with the weight of the motorcycle.

As we discussed earlier, adjusting the tyre pressure a bit to meet the rider’s expectations is not going to damage the tyres much. Is a puncture more likely to occur in an under-inflated tyre or an over-inflated one?

The likelihood is greater in an under-inflated tyre.

Is there a myth about tyres that you would like to dispel right now?

One of the myths which I definitely want to address to the public at large is that the tyre is not a maintenance-free product. If you forget about tyres and do nothing about them, it will still last its life is a complete myth. You need to do three important things when it comes to the maintenance of a tyre. The first and foremost is make sure that you check the tyre pressure and ensure that it is within the range of the recommended pressures. Second, inspect your tyre on the tread to ensure that there is enough rubber available for you to have a safe ride, especially on wet surfaces. Third, look around the tyre, feel the tyre for any damages resulting from wear and tear, either a sharp object penetration or anything of that sort which has ruptured the inherent carcass of the tyre or the reinforcement material of the tyres which can lead to a blowout.

Is there something you feel the public does not know about tyres or something that you find extremely interesting about them?

A very interesting aspect about tyres is that it is one of the engineered products which has the highest safety factor. Even a Boeing aircraft does not have so much safety factor built into it. The safety factor for the tyre is in the range of seven to eight; in fact, sometimes even more. What do I mean by safety factor? That means it can endure loads or endure stress and strain seven or eight times more than its intended design loads and stresses.