If you have a tire pressure gauge and need to check your bike, you may be wondering if this will work…
Can you use a car tire pressure gauge on a bike?
It depends on the bike and the type of tire pressure gauge – as you have very specific valves to deal with – but usually, it will work fine. This is because Bicycles typically use a Presta valve, as these types of valves can hold more pressure and will self-seal from said pressure.
With cars, you typically are dealing with Schrader valve, which is important, as these have the same kind of diameter and valving setup, and thus should be compatible. That said, a bike pressure gauge is only a few dollars, so it’s good to get a gauge just for your bike that you can keep with your other gear.
Is car PSI the same as bike PSI?
No, car and bike PSI ratings will be different, mostly because of the width of the tires. Wider tires, such as cars have, require about 25 to 30 PSI to function well, while thinner, standard bike tires will require a much higher range – usually 80 – 110 PSI, although hybrids and mountain bikes will require 40 -70 and 25-35, respectively.
How do you measure PSI on a bike tire?
While some cycling vets like to simply squeeze the tires, we simply cannot recommend this. A tire gauge is a proper way to do things and it’s going to be the accurate way, as well.
You can get one of these at just about any department or automotive store and often for less than 5$, so you’ll want to get a tire gauge and use it at least twice a week to check your bike.
Why are bike psi higher than cars?
Thinner tires require more PSI for holding you and also for negotiating corners. With cars, you have wider tires, plus the suspension and all that other machinery in place to ensure that weight is distributed evenly.
When you are on a bike, however, all of that weight needs to be supported on two, rolling and very thin tires, as well as a lightweight frame. As such, a higher PSI is going to be required to support your weight moving forward and especially when leaning into turns.
Why are bike tire pressures so high?
Bike tires are built for traversing smooth roads or mountain bikes, for uneven terrain, and that extra pressure is what makes the tires function as designed.
This is in part by supporting your weight with only thin areas of rubber touching the terrain, but it’s also because once they are fully inflated they are going to roll efficiently and only the intended areas of tread will be touching the ground in the process.
When a bike tire is low on pressure, then the tire is essentially deformed, and as a result, you get additional friction that the tires are not meant for, as well as extra weight on the frame that is no longer properly distributed.
That high pressure is thus integral to making your tires do what they need to support you and the bike when they are in motion or at rest.
Is 40 psi too high for a bike?
It may be too low, actually, depending on the type of bike tires. If you have hybrid tires, for instance, then the optimal PSI pressure will be in a range of 40 – 70, so you might be okay in this case. With standard road tires, however, you would be woefully low – these need 80 – 110 PSI.
Finally, for mountain bikes, 40 would be too high, as they usually run on 25 – 35 PSI. As such, it’s important to know the recommended pressure for your specific set of tires so that you can check them weekly to ensure that they are not too low or too high!
What happens if you ride a bike with low tire pressure?
If the pressure is very close to what it’s supposed to be, then your bike might be okay for a distance of up to 50 miles or about 1 hour of operation. That said, we don’t recommend this. When your bike tires don’t have enough pressure, then they are not well-equipped to support your weight.
This causes the tires to essentially deform so that portions of the tread that normally never touch the ground will be getting friction. Your weight may also cause more air to leave the tires quickly in the case of a leak and if they are too low, you might even damage the wheels.
As such, if the pressure is too low, then you really shouldn’t ride the bike at all if you can avoid it.
Is it harder to ride a bike with low tire pressure?
Yes, it will be harder to ride the bike, as the tire will be touching the terrain differently. When fully inflated to the right PSI, only the portions of the tread designed for the terrain should be touching it, but when it’s low then other parts of the tire will touch the road and overall friction is increased.
In time, this can strip portions of the tire and accelerate air loss if there is a leak involved.
At the very least, you’ll feel less control in steering and the bike will be slower, so it’s a good practice to stop riding your bike whenever you feel a shift in a performance like this – otherwise, that low pressure can quickly become a problem capable of damaging your bike or even causing an accident.
Can you pump a bike tire with your mouth?
You could conceivably do this, but this is at best a makeshift method to increase the pressure slightly so that you can get the bike home. Standard tires require a high PSI, although you might get away with blowing up the tire with your mouth with a lower PSI tire such as on a mountain bike.
For a standard one, however, the high PSI required is going to be taxing if you are trying to blow it up with your mouth, and that description is a fairly generous one. It’s a good idea to always make sure that a portable bike pump is part of your gear or if you don’t have it, try a local gas station.
Is a digital tire pressure gauge accurate?
In most cases, yes, digital tire gauges are pretty darn accurate. Some models will even include illumination so that you can read them in the dark and it’s worth spending a little extra to get this feature.
Extremely cheap digital models are usually accurate but don’t last for very long, so when you are looking for a digital gauge then use your best judgment – you do get what you pay for and this is something that you’ll be using twice a week for the lifetime of your bike.