Are wider tires & lower pressures REALLY faster?

Whilst younger cyclists may instantly buy into the new trend of wider tires at lower pressures is actually faster, for older guys like me who were brought up on racing on 18mm or 21mm tires pumped up to 120 to 160 psi this relatively new idea is hard to believe.

What makes sense in my mid is very hard, skinny tires are:

  • More aero as there is less frontal area to push through the wind than a fat tire
  • Skinnier tires use less material to make them and so are more lightweight
  • I actually feel like I am going faster when the tires are pumped up hard or more correctly soft tires feel slow
  • You are more likely to get a puncture on soft or under-inflated tires

But do these perceived advantages or even real ones (in terms of the aero benefit of thin tires) actually add up to make for a faster bike?

Just Hype?

Well as you know there has been a lot of debate on this subject over the last few years and the trend to wider tires at lower pressures continues to gather momentum. However my reservation has always been that perhaps is this just hype or maybe it is just aimed at recreational and long distance cyclists, where the comfort factor may outweigh a slight loss in speed?

Also there are times when just following what the pros do, does not make sense as you need to remember that they are paid to use certain equipment, thus it may or may not always be the best choice, rather just what their sponsors want them to use. Then it is also worth keeping in mind that their races tend to be very long with many, many hours spent in the saddle, thus being comfortable on the bike is really important to them. So perhaps for a pro, the added comfort levels of softer, wider tires more than makeup for a slight loss in speed?

However for me as an amateur here in France, even in the elite category, our races tend to be fairly short (but very fast), so in that relatively short period of time I can put up with a little less comfort in the pursuit of the fastest setup possible. I also wonder would fat, low pressure tires really make you faster on a shortish time trial?

So for me and my type of racing, I have always been really skeptical and whilst I have now swapped to wider (25mm) tubs for racing because they match my wider 3T Orbis II rims, I still can’t stop myself from pumping them up to the maximum recommended pressure on race day…

Vittoria Corsa CX tires on 3T Orbis II Ltd Wheels

The Evidence

In an effort to finally settle this debate (in my mind anyway), I have decided to gather all the evidence that I come across and put it all in one place. I have kept in mind to especially focus on the evidence and information in relation to serious amateur road racing, criteriums and shorter time trials as opposed to leisure rides, touring or century riding.

CyclingTips Podcast
One of the best arguments for softer and wider tires that I have come across is on this really fascinating podcast from CyclingTips, that I really suggest that you take some time to listen to:

schwalbe-tiresSchwalbe Tires
Tire manufacturer Schwalbe has a nice section on their site that explains rolling resistance, what factors are involved and a good section of why wide tires roll better than narrow ones and goes into topics like tire deflection and is a good place to get started:

So what Pressures Should you Ride

Wheel load vs pressure graph by Frank Berto
Wheel load vs pressure graph by Frank Berto

Ok, so if you have been converted, then what pressures should you actually be riding? It is not as simple as just letting out some air as different bike and rider weights will have different optimal pressures. Indeed it gets even more tricky than this as your optimal tire pressure will be different depending on the load placed on each tire. So because your weight is most probably not distributed evenly on the bike, the optimal tire pressure on the front will be different than that for the rear wheel.

Here to there is a lot of info out there and so to start with, I found these documents and chart written by Frank Berto (who was amongst many other things the engineering editor of Bicycling Magazine for many years) that are an excellent place to start:

Whilst published way back in 2006, these documents explain tire drop and recommended tire pressures, which are according to Frank Berto still completely relevant today:

That’s it for now, I will of course be adding to this page as and when I unearth some more information and evidence. For now I’m definitely going to start experimenting with lower pressures, however I really still cannot see my self racing on tires at or under 70 psi…

Your Thoughts

Do you have any sources that may be of interest to add to this page? I would also love to hear your thoughts, opinions and experiences regarding tire widths and pressures – please feel free to leave a comment in the section located at the bottom of this page:

Share