Outdoor

How to get the correct tire pressure for bicycle tires?

The pressure that you choose for your bicycle tires, whether it is a road bike, mountain bike, or hybrid, plays a huge part in comfort and safety.  

In this guide, we look at how to get the best tire pressure for your riding style and conditions.  

The importance of tire pressure on bicycles

Tire pressure has two primary impacts on how your tires perform: first, it affects grip; second, it affects rolling resistance.

Grip levels 

The more that a tire can conform to and make contact with the surface that it is rolling over, the greater the grip level that it achieves. This means that an over-inflated tire that bounces over a surface and rolls only on the central strip will not have a good grip. 

Rolling resistance 

Rolling resistance is how much friction occurs between the tire and surface; the greater the friction, the greater the resistance. An underinflated tire will provide too much contact with the surface, and therefore too much rolling resistance. Perhaps surprisingly, an over-inflated tire also increases rolling resistance; because it constantly bounces on the surface, rather than rolling smoothly along with it. 

To achieve the best grip level and rolling resistance level, it is vital to get the correct tire pressure in your bike tires. 

Inner tube vs. Tubeless tires

When considering tire pressure, you have to take into account whether you have clincher tires fitted with inner tubes on your bike, or whether you have tubeless tires.  

Tires with inner tubes can be more subject to ‘pinch flat’ punctures if you run a low pressure; this occurs when a large impact on the tire causes the tire’s bead to pinch the inner tube and puncture it. ‘Pinch Flats’ are not possible on tubeless tires, because there is no tube to pinch.

Because of the risk of inner tube pinch flats, sometimes you need to run a slightly higher pressure than would be optimal in an inner tube set-up, to reduce the risk of puncturing.

Tubeless tires like the Schwalbe G-One can be run at lower pressures

The correct tire pressure guide

The best tire pressure for your bike will depend on the kind of bike you have, the kind of tires you have fitted; and also factors like rider weight, road conditions, and weather conditions.  

Mountain bike tire pressures

Tire Pressure

Mountain bike tires are run at a lower pressure than road tires so that the tire can conform to the terrain, and provide added grip. 

The added volume in a mountain bike tire means despite these lower pressures, it is less likely to pinch flat. 

  • Suggested tire pressure for mountain bike tires – for a ≤70Kg rider: 
  • Inner tube tire: 36PSI (2.5Bar) Front / 38PSI (2.6Bar) Rear 
  • Tubeless tire: 26PSI (1.8Bar) Front / 28PSI (1.9Bar) Rear 
  • Adjust for weight: Add 1 PSI for every 5Kg over 70Kg 

The large volume of mountain bike tires means they can be run at low pressures

Road bike tire pressures

Road Bike Tire Pressure

Road bike tires are run at a higher pressure than mountain bike tires, to reduce rolling resistance and the chance of ‘pinch flat’ punctures.  

  • Suggested tire pressure for road bike tires (25mm) – for a ≤70Kg rider: 
  • Inner tube tire: 90PSI (6.2Bar) Front / 93PSI (6.4Bar) Rear 
  • Tubeless tire: 80PSI (5.5Bar) Front / 83PSI (5.7Bar) Rear 
  • Adjust for weight: Add 2PSI for every 5Kg over 70Kg 
  • Subtract 2PSI for every 5Kg under 70Kg 

Narrow road bike tires require the highest pressure

Cyclocross/Gravel bike tire pressures

Tire Pressure

Cyclocross tires are run at a higher pressure than mountain bike tires, but a lower pressure than narrower road bike tires; providing the best compromise between grip and rolling resistance. 

  • Suggested tire pressure for cyclocross tires (35mm) – for a ≤70Kg rider: 
  • Inner tube tire: 48PSI (3.3Bar) Front / 50PSI (3.5Bar) Rear 
  • Tubeless tire: 36PSI (2.5Bar) Front / 38PSI (2.6Bar) Rear 
  • Adjust for weight: Add 1PSI for every 5Kg over 70Kg

The greater volume of CX tires allows you to run lower pressure than road bike tires

Hybrid/City bike tire pressures

Tire Pressure

A hybrid bike tire is similar in volume to a cyclocross tire, so the pressures are also similar: 

  • Suggested tire pressure for city bike tires (35mm) – for a ≤70Kg rider: 
  • Inner tube tire: 50PSI (3.4Bar) Front / 55PSI (3.8Bar) Rear 
  • Tubeless tire: 38PSI (2.6Bar) Front / 40PSI (2.75Bar) Rear 
  • Adjust for weight: Add 1PSI for every 5Kg over 70Kg 

Tire pressure for turbo trainers

Tire Pressure

Riding using a turbo trainer removes many of the benefits lower tire pressure provides. In fact, there are few reasons to want to reduce your tire pressure on a turbo, while it may adversely affect the power output registered by your trainer.

Generally, 100 PSI is the standard pressure setting for a wheel-on turbo, but this can be reduced by 10 PSI or so if you’re experiencing a lot of tire slippage.    

Adjusting tire pressure for wet conditions 

Many riders advise that they drop their tire pressure in wet riding conditions.  

In reality, the necessity to do this is not that great, assuming you have the correct tire pressure initially. After all, most people (including professional bike racers) would not stop mid-ride and lower their pressures if it began to rain.  

If you do decide to lower your tire pressure from the above recommendations, then do so by only 2 PSI; any significant reduction may actually cause the tire to squirm more, making it unstable on the road or trail surface. 

Adjusting tire pressure for wet conditions might not be necessary

Refining your ride 

The above numbers for recommended bike tire pressure are fairly specific, and some riders may say there is no hope of their pump (especially their hand-pump) of being that accurate. 

The good news is that with the advent of digital gauges on floor pumps and hand pumps, the accuracy of your tire pressure inflation can be really on point.