A Beginner’s Guide to the Perfect Electric Bike Tire Pressure
There is a huge amount of debate around how to get the ideal e-bike tire pressure. Optimum pressure varies due to a number of factors, and because of this, there are no fixed rules. Keep in mind, the same physics and factors that apply to regular bicycles also apply to electric bikes, and there are certain guidelines that you can follow to approximate the correct pressure for an electric bike wheel. From there you can make adjustments to fine tune it.
The Effects of Tire Pressure
Physics tells us that more pressure will allow a bicycle to roll faster because the tire will deform less and have a smaller footprint on the road, both of which lead to less rolling resistance. While this is true, it is only true on a perfectly smooth road. Unfortunately, the reality is that road surfaces vary greatly, and they are rarely smooth at all.
Studies have found that decreasing pressure can actually increase speed, as small bumps are absorbed by the e-bike tires instead of reaching the actual bike. Perception of speed is increased with higher pressure because more vibrations reach the rider, making them feel like they are moving faster.
The effect is easy to understand if you have ever ridden a mountain or off-road bike with tires pumped up hard. Every bump on the trail is transferred to the rider. While a hard tire has a smaller footprint and will indeed accelerate faster, mountain bikers need a lower pressure so that the bigger tire footprint can conform to the trail and give more grip, especially when cornering.
Although there is no one ideal bike tire pressure, you can get close to what you need by considering the following factors and steps below:
More weight pushing down on the e-bike tires will compress the air inside more. The more that the rider and bicycle weigh, the more pressure is needed to counter the effect of this compression. If you are a petite rider, then you will need a much lower pressure in comparison to a larger cyclist.
Road cyclists need the highest tire pressure for their electric city bikes. Trekking cyclists or “bike packers” (similar to backpacking but with a bicycle) riding on fire trails will need a lower tire pressure, and mountain bikers need even less.
Rough terrain will require road cyclists to use a lower pressure to avoid vibrations that cause hand fatigue. Likewise, when riding off-road, a higher pressure is more suitable for hard-packed surfaces than loose sand or loam, which require a lower pressure. Keep in mind that, if your tire pressure is too low, it can cause snakebite punctures when riding off-road.
If the surface is wet, the ideal bike tire pressure will be much lower. This increases the e-bike tire’s footprint and grip. This applies to road and off-road cycling. A tire pressure that is too high is often the primary cause for crashing when road conditions are wet.
Tire Volume and Rim Width
As tire volume increases, lower pressure will be needed to get the same ride feel. The same applies to rim width. Mountain bike rims have become wider in the last few years. A wider rim allows a tire to have a greater surface volume, which grips the road better.
How to Get the Ideal Tire Pressure
- The minimum and maximum pressure should be visible on the side of the tire. Although this is a guideline, you should not exceed the maximum. Refer to the manufacturer’s website for an approximate pressure according to your body weight, and use this as a starting point. Make adjustments according to the above considerations.
- Get a small portable pressure gauge and inflate your tires to the correct pressure on longer rides or regular commutes.
- Go for a ride. Take a pump and your pressure gauge with you. If you are riding on the road and notice lots of vibration, release five psi of pressure, and try again. If you are riding off-road and notice your tires bouncing off stones and roots, you should also release five psi. On the other hand, if you notice that your rim is hitting objects as you ride over them, you have far too little pressure in your tires.
- Experiment with different pressures. If you use a GPS tracker, you can see how different tire pressures affect your speed. You can ride a short section of trail many times. Start with a low pressure, and add five psi each time until the tire starts bouncing off objects. Where did it feel best? Which pressure gave you the best grip in the corners? How does this change with different surfaces?
Be Prepared to Adjust the Pressure
While there is no perfect tire pressure, it is certainly worth taking the time to play around with it and find what pressure works best for you and your style of riding. Bear in mind that, as soon as you are riding on a different road surface or different kind of soil, the pressure you need will change. The same is true if it starts raining during a ride. The more you experiment with tire pressure, the more accurately you will be able to judge which pressure is right for you in every scenario.
At the end of the day, it costs nothing to inflate your tires a bit more or let out some air, so get out there and find the pressure that works best for you!