What's wrong with my tires?

[Eggs]

Hey, I'm new here! I really wanted to get some help with my bike tires. It's a budget leisure bike, something suitable for only riding every once in a while I suppose.
Over the past couple of months, even after replacing the tire valves the air keeps escaping (no holes but I'm not sure how to check for leaks). I've replaced the valves once, and other times I've resorted to wrapping the valve in teflon tape since I didn't have any other choice.

Should I replace the tires entirely? Thanks a lot in advance!

 

[Brandane]

Not sure how basic you want us to go here, but here goes:
It's unlikely that your bike has tubeless tyres, therefore the problem will lie with the inner tube (part of which is the valve). The inner tube is a rubber tube inside the tyre which should hold the air. Obviously sharp things which embed themselves in the tyre might make their way through the tyre and puncture the inner tube. Glass, nails, thorns etc. are common culprits. Or "pinch punctures" from riding up kerbs with soft tyres.
The only real way to check for leaks is to remove the wheel, then remove the tyre. If you don't know how to do this then you need to learn; it's the most basic part of bike maintenance (apart from oiling the chain) and if you don't know how to fix a puncture you might find yourself stranded at some point. There are many videos on YouTube showing how to remove and refit a tyre.
Once tyre is removed, check inner tube for leaks. It might be obvious, it might not be. Partially inflate tube and pass sections of it through a basin of water. You will see bubbles from the leak. Remember there might well be more than one leak. Repair the puncture (google or YT is your friend) or replace the tube with a new one. Check inside of tyre for anything sharp which might be the source of puncture, and remove it. Refit tyre and tube, refit wheel. Inflate tyre to proper pressure, which is important to lessen the chances of punctures in future. Check pressure regularly; I usually do it every week if riding regularly - or before a ride if the bike has been sitting more than a week.

Edit to add - you might get a better response to this in "Beginners", or "Maintenance and Repairs" rather than Bike Buying Advice. Maybe admin will move it.

 

[Pat "5mph"]

Mod Note:
Great comprehensive answer @Brandane
I moved the thread to components

 

[Chris S]

Hey, I'm new here! I really wanted to get some help with my bike tires. It's a budget leisure bike, something suitable for only riding every once in a while I suppose.
Over the past couple of months, even after replacing the tire valves the air keeps escaping (no holes but I'm not sure how to check for leaks). I've replaced the valves once, and other times I've resorted to wrapping the valve in teflon tape since I didn't have any other choice.

Should I replace the tires entirely? Thanks a lot in advance!

That's a Dunlop/Woods/German valve. They leak more than modern valves anyway. I reduced it by smearing a tiny amount of Bostik glue around the edge of the valve tube before I put the valve in. You could also use silicone sealant or anything that's going to create a rubbery ring.

 

[Eggs]

Not sure how basic you want us to go here, but here goes:
It's unlikely that your bike has tubeless tyres, therefore the problem will lie with the inner tube (part of which is the valve). The inner tube is a rubber tube inside the tyre which should hold the air. Obviously sharp things which embed themselves in the tyre might make their way through the tyre and puncture the inner tube. Glass, nails, thorns etc. are common culprits. Or "pinch punctures" from riding up kerbs with soft tyres.
The only real way to check for leaks is to remove the wheel, then remove the tyre. If you don't know how to do this then you need to learn; it's the most basic part of bike maintenance (apart from oiling the chain) and if you don't know how to fix a puncture you might find yourself stranded at some point. There are many videos on YouTube showing how to remove and refit a tyre.
Once tyre is removed, check inner tube for leaks. It might be obvious, it might not be. Partially inflate tube and pass sections of it through a basin of water. You will see bubbles from the leak. Remember there might well be more than one leak. Repair the puncture (google or YT is your friend) or replace the tube with a new one. Check inside of tyre for anything sharp which might be the source of puncture, and remove it. Refit tyre and tube, refit wheel. Inflate tyre to proper pressure, which is important to lessen the chances of punctures in future. Check pressure regularly; I usually do it every week if riding regularly - or before a ride if the bike has been sitting more than a week.

Edit to add - you might get a better response to this in "Beginners", or "Maintenance and Repairs" rather than Bike Buying Advice. Maybe admin will move it.

Thank you so much for the detailed reply! I appreciate it a lot.

That's a Dunlop/Woods/German valve. They leak more than modern valves anyway. I reduced it by smearing a tiny amount of Bostik glue around the edge of the valve tube before I put the valve in. You could also use silicone sealant or anything that's going to create a rubbery ring.

Thank you so much! I will give that a try as well.