Everybody must pump the tires of their road bike, but if you pay attention, you’ll notice that cyclists tend to have different ideas regarding where exactly the needle should stop on the gauge. Many of those people act this way because they have heard one rumor and stuck with it so they don’t even realize they may be wrong.
There are quite a lot of people who think that adding a high amount of pressure to the tires is going to make the bike ride faster, but that may only be true if we are talking about some indoor track racing applications. This myth came to be because, in the past, it was believed that the friction between the tire and the road was highly important for resistance.
Now we know that, actually, that friction between the tires and the road has only a rather small effect on the overall rolling resistance. The rolling distance is impacted directly by two factors. One of them is the amount of energy that is lost within the tire’s casing, while the second one is suspension loss.
The road bike pressure
Finding out the sweet spot for road bikes can be a bit tricky, so it’s no wonder that many people didn’t even really try or did so only superficially. This is because you will need to find a sweet spot pressure that can create the perfect balance between managing hysteresis losses and the suspension losses.
Naturally, things can get directly influenced by how rough the surface of the road you are traveling on can get. Regardless, one thing that you can be sure the vast majority of people are doing is that they’ll run too much air pressure in the tires of their bikes, even more so people who can be considered to be light riders.
People who use 25-28c tires are no exception to usually overdoing it, either. There have been studies done, actually, which have proven that the best rolling performance appears if the tires can sag about 15 – 20% under your weight, as a rider. This is actually really similar to the suspension sag that is needed on mountain bikes as well.
Unfortunately, yes, you have probably guessed it by now – measuring the tire sag is not a very easy task, if not downright hard. Fortunately, there is also some good news: you can find cheat sheets that have the role of helping you smooth the entire process, all by taking into consideration the weight that you have and the size of the tires.
What can tire pressure affect?
Tire pressure is highly important for a variety of reasons, which will have an impact on how your overall ride will be. Among those things, we can mention the rolling efficiency, riding comfort, your stability, and grip when taking a corner, plus the resistance to puncture and the pinch flats. As you can tell, all are very important.
For rolling efficiency, what you really must know is that if a tire has a pressure above 110 psi, then you should only use it on a road that is really smooth. This means that you can take advantage of the rolling resistance that is reduced when the pressure is high, but without having the tire’s ability to absorb bumps being overwhelmed by this.
Directly connected to the rolling efficiency is the ride comfort. In some cases, you may want to actually lower the pressure below the recommended level for a high efficiency in rolling. This will make you less powerful on smooth pavement, yes, but it will also keep the body from getting tired from all the vibrations.
Talking about the cornering aspect, it is also rightfully assumed that if the pressure in the tires is lower, then you will also have a better time when it comes to cornering. In the case that the pressure is too high, the tires can skip and bounce when coming across rough corners, which will make you slow down.
As for road puncture, there are a lot of brands and experts out there who claim that lower pressure is going to drastically reduce the chance of puncturing the tires while you are out there on the road. Basically, if the tire is more on the supple side, it will also have the ability to flex around the objects that may cause punctures.
This is also a double-edged sword, as if the pressure is too low, then there is a higher risk of having a pinch flat happening, which you may also know under the name snake bike puncture. In this case, the tire or inner tube is pinched as a result of the fact that the wheel is bottoming on the surface of the road.
So, now that you really have to decide exactly on the pressure that you are going to apply to your bike tires, you must remember the most important factors: the tire size when it is inflated, your weight, plus what the road surface conditions will be like. It’s not that easy, but it’s not that hard either.
When you start measuring the tire, again, don’t forget that you actually need to pay attention to the inflated size, not the non-inflated one. As an example, a tire that is about 23 mm will actually grow in size quite a bit, to maybe 26 mm; the result is that the tire should now be treated as a 25 – 26 mm tire.
So, if the tire size is 25 mm, for somebody who weighs less than 140 pounds, the psi should be around 60. The psi will grow to about 67 if the rider has a weight between 140 and 180 pounds, while if you weigh more than 180 pounds, you will need 75 psi for properly using the bicycle.
With regards to the conditions you will have on the surface you will be riding, that is, unfortunately, most likely a case of finding out the correct answer by using the classic trial and error method. You can also use a power meter to come up with the right answer. If the road surface is truly awful, drop the pressure by at least 10 psi.
You should probably know by now that you ought to check the pressure from time to time and reinflate the tires as needed so you will get the best performance out of your bike. It is recommended that you do a little check on your bike’s pressure about once a week. The majority of people don’t, but that is a great way of staying ready.
This is how you find yourself in situations in which you feel like you are going slower, day by day until finally, you realize that the tires need air. This makes your bike go slower, not as smooth as you are used to, and, on top of that, you make your tires and inner tubes be at a greater risk of suffering some punctures.
Of course, as you start pumping up, you need to be very careful and not overdo it. In the case that you do overinflate, there is a very big chance that you will soon enough get scared by the explosion that will follow (yes, the tube will explode) and you’ll need to replace the tire and inner tube altogether.
The simplest way of finding out if your tires need some air is to do the thumb test. That involves pressing your thumb on the tires and feeling if they are getting soft. You don’t need to be an expert in bicycles or tires for you to be able to do this and learn when it’s the moment that you need to make the change.
The other way of doing this is by using a floor bike pump. We are talking about the models that can stand on their own and that have a pressure gauge. You will find the recommended pressure written on the side of the bike tire, as per the manufacturer’s rules. Clearly, staying between the ranges that are recommended is the best way to go.
If you also have a mountain bike, you will notice that the pressures for a road bike are higher; meanwhile, hybrid bikes will fall somewhere in the middle. If you are still unsure, you can just ask your local bike shop about these aspects, but we know you will get the same answer.