A little over 5 years ago I bought a Magna bicycle. Within the first summer of riding it the rear brake fell apart. I finally got around to having he brake fixed this past month but I am worried about the quality of the tires as the bike (which has been hanging in my un-insulated garage for 5 years with many cold winters) has not had the tires inflated in 5 years. I recently checked the PSI on the tires with my gauge and it is 2 PSI. I'm wondering if I should get the tires replaced. I haven't tried putting any air into them as I don't want the tires to pop. Any help is appreciated.
If the bike has been hanging rather than sitting with weight on the tyres (and hence damaging the sidewalls), there is a good chance the tyres are still ok.
You can check the tyres by going around and looking for hairline cracks in the rubber and feeling if the rubber is brittle/flaky.
If they look ok then go ahead and inflate them and recheck the following day. If they still show no obvious signs of damage then I would go ahead and ride them.
There are ways tires get damaged other than by having weight on them. For example, ozone and ultraviolet light can cause dry rot.
If the tires were stored in a cool area, out of sunlight, and not near any electrical equipment, they're likely fine.
If, however, they display cracks, or are brittle, or were stored in sunlight or near electrical equipment, I'd recommend replacing them along with your tubes.
I assume it's very unlikely that a tire gets damaged because of not being inflated. I would be more worried about how brittle and hard the rubber got during the years. Some tires are more - some less affected by this. Especially when you are planing to ride also in the wet a front tire with hard and brittle rubber can be a serious safety issue.
In my experience, it is not the winter that ruins tires but rather the harsh summers. Heat causes the tires to expand. Although vinyl is elastic, it has certain limits.
I would say ride for about a mile. Check the tire afterwards because some cracks are insignificant and were probably going to develop either way. Other cracks do not last long.
I received a bike with cracked tires one and I had the same question but it lasted me several months.
There are two important parts to a tire, the tread and the inner tire. When tires are no good,the inner tire is typically fibrous and falls apart. Tires are not good when the tread is depleted. Only way to figure any of this out is to actually strain the tires and go from there.
I would inspect the tire tread and inner tire before riding and then after riding. When the inner tire fibers have come loose, the tread will wear out easily despite excellent tread. This is because the fibers hold the tread in place while riding and prevent significant deformations.
I would even go as far as saying the inner tire is more important than the tread here because tires with excellent tread will still deform when riding if the inner tire has loose fibers. Also, loose fibers will cause the tread to rip. Cracks tend to occur in tires simply because of the constant deformation that tires go through and then weather imbalances the chemicals inside of it. So it is possible that the tire has cracks but the fibers still hold up.
Thicker tires such as those on mountain bikes and the like will often have cracks but still be good. With road bike tires, cracks tend to be more common with loose fibers. So if a road bike, these cracks have a higher chance of loose fibers than does a mountain bike. Mountain bike tire have very strong inner tire fibers. You might not even notice the fibers because they may be covered in any bike or they might be uncovered.
But like I said, ride the bike and take notice of any changes. If fibers cannot be observed, try deforming tire by folding it around the cracks and fold it at other locations where there are no cracks. Two things should happen. Cracks shouldn't form where they weren't, and cracks shouldn't worsen where they are.
Tires should be ok, just ck for cracks as said above.
Use the airchuck.
Remove the wheel.
Inflate to about 5 psi so you can squeeze with your hand.
Check that the tire bead is set around the whole rim, and spaced fairly evenly. Inflate to 15 psi Roll the tire on floor and ck bead again. Inflate to at least 20-25 psi
For hybrid tires 35-45psi Road tires 80-120 Hope this helps :)