Skip to main content
32 votes
Accepted

Why does the manual for the inner tube say the maximum pressure is 4.5 PSI?

Most likely this low number refers to inflating the tubes without the tire, as a balloon. When installed inside a tire, the majority of air pressure is held by the tire casing, not by the tube. A ...
Grigory Rechistov's user avatar
32 votes
Accepted

Tyre exploded while riding

TLDR answer: you ran over something Given the ding/cut in the rim itself that aligns with the cut in the tire, you ran over something metal that was sharp enough to cut your tire and even dig into ...
Andrew Henle's user avatar
  • 10.6k
23 votes

Why is my inner tube not distributing air evenly in it?

If you are just inflating a tube alone, it will be uneven above a certain pressure. It is not supposed to hold significant pressure on its own. It is used inside a tyre. If you did not overstretch it, ...
Vladimir F Героям слава's user avatar
22 votes
Accepted

How to find punctures in inner tubes?

Do whatever works, really. The problem with the container of water approach is that it requires a container of water. It won't damage the tube. Also, if you need to patch the tube, you have to wait ...
Batman's user avatar
  • 46.2k
22 votes

Tyre exploded while riding

Definitely a cut - the damage to the rim and the fact that the rubber and carcass fibers are clean cut through confirm that. If the tire burst from over pressure you'd see ragged edges. Also, from ...
Argenti Apparatus's user avatar
21 votes

Does anyone patch inner tubes anymore?

Yes, some people still patch their tubes I've worked sales at a bike shop for three years, and patch kits are still one of the most common small items for us to sell. It still makes sense from an ...
Jasmine's user avatar
  • 410
20 votes

Unable to get a tube replacement to last

There is a mark in the middle of the valve stem as if something has pressed against it: Given that it was a fresh new tube, it likely means that it had been installed with the valve protruding at a ...
Grigory Rechistov's user avatar
20 votes

Unable to get a tube replacement to last

Check that the rim tape (tape or liner that sits in rim bed) is not loose or spinning. I had an identical issue where a brand new tube would be ruined after a 10 minute ride. The rim tape spins on ...
Warren Burton's user avatar
19 votes

Presta Valve Keeps Ripping From Tube

The usual causes for this: Presta valve in Schraeder hole without proper reinforcing grommet. Valve crooked, or being forced crooked at the expense of extra stress on the tube/valve joint by riding ...
Nathan Knutson's user avatar
19 votes
Accepted

New wheel. Does it need that little rubber lining between it and the tube?

Yes, you will need a rim tape to protect your inner tube from the spoke holes or the spokes in your rim. There are a few exceptions we come to later. The rim is the outer part of your wheel. Along ...
gschenk's user avatar
  • 9,778
18 votes
Accepted

Why using a puncture repair kit instead of a new inner tube?

You have to remove the wheel to replace the tube. A repair can be done in the frame. On older bikes without quick release, and with current gear hubs, electric hubs, Nuvinci hubs, belts etc, you need ...
Henry Crun's user avatar
  • 1,068
18 votes

Can I pump my MTB tire to max (55 psi / 380 kPa) without the tube inside bursting?

It can't burst the tube, because the tube is completely surrounded by the tyre and rim. Bear in mind, though, that higher pressures don't automatically mean a faster ride. There are two competing ...
David Richerby's user avatar
18 votes
Accepted

Unable to pump air in my bicycle tube

I think its worse than that - your valve core is not there, but the thinner thread where you connect the airhose is there. That tells me the shaft of the valve core broke off, the acorn nut was lost, ...
Criggie's user avatar
  • 125k
17 votes

How to find punctures in inner tubes?

To follow up on what Batman says, what you use to find the leak depends a lot on the circumstances. If you get a flat by the side of the road (and you don't have a spare tube) then you obviously can'...
Daniel R Hicks's user avatar
17 votes

How can I patch a hole on the underside of an inner tube?

It does not matter on which side the hole is, the process is exactly the same anywhere on the tube. Be sure to let the glue become more viscous and sticky by waiting for a while before applying the ...
Vladimir F Героям слава's user avatar
17 votes

Are 26'' wheels and tubes a thing of the past?

The sheer number of bikes in the world with 26" wheels means finding a tire is unlikely to be a big problem for a long time, if ever. Plenty of BSO's being sold are still 26" and there are ...
mattnz's user avatar
  • 50.9k
16 votes
Accepted

Technique for self-adhesive puncture repair patches

This kind of failure is basically the reason sticker-type patches have a reputation for not being reliable. Scrupulously sanding the area and getting it as clean as possible (ie, with alcohol or ...
Nathan Knutson's user avatar
16 votes

Why does the manual for the inner tube say the maximum pressure is 4.5 PSI?

It is common to inflate a tube just a little bit before you install it in the tyre. This gives it some shape and helps prevent it getting twisted or pinched, with a little care from the user. This is ...
Swifty's user avatar
  • 12.8k
16 votes

Why did my road bike tire patch fail?

Bike shops don't patch tyres because at $60-100 per hour its not worth their time compared to a new tube. Road tubes can absolutely be patched, however its harder with thicker patches - try and get ...
Criggie's user avatar
  • 125k
15 votes

Heavy Rider (300lb+) - Please recommend a 26" tyre to avoid tyre pinch

As a heavy rider personally, I don't have many issues with flats. A normal tire on the high/maximum pressure works fine to avoid pinch flats. The key is to check tire pressure every time you get ...
zenbike's user avatar
  • 29.8k
15 votes
Accepted

Why is my inner tube not distributing air evenly in it?

Tubes aren't designed to be stretched; they are simply there to hold the air while the rim and tire contain the pressure. Consider what happens when you blow up a long thin balloon. First, the loose ...
Ray Butterworth's user avatar
14 votes
Accepted

New high quality tire doesn't sit evenly on the rim

The tire sidewall is just hung up on the rim a little. It’s a common problem. Deflate the tire until you can deform it a little with your hands, rotate the wheel so the problematic section is at the ...
Argenti Apparatus's user avatar
14 votes

Does anyone patch inner tubes anymore?

Yes - absolutely, though not on the roadside. Here's a spare tube out of what was my main commuter. I counted and it has 15 patches applied, though some of them are snake bites and get two. Presuming ...
Criggie's user avatar
  • 125k
13 votes
Accepted

New inner tube bulges near the valve when inflated

Unless the tire bead (the re-enforcing wire around the edges) is damaged your tire is simply not seated on the rim properly near the valve and has popped off as the tube was inflated. Tube size seems ...
Argenti Apparatus's user avatar
13 votes

New high quality tire doesn't sit evenly on the rim

Sometimes I've found that pumping up the tyre to the rated pressure (or a little over), deflating most of the way, and pumping up again does the trick. You can chuck some water on the bead while its ...
Chris H's user avatar
  • 59.7k
13 votes

Technique for self-adhesive puncture repair patches

I believe pre-glued patches were always intended to be a temporary fix to get you home. When they first came out on the market I remember explicit warnings that these were not a permanent fix. ...
Rider_X's user avatar
  • 30.7k
13 votes

Unable to pump air in my bicycle tube

You seem to be missing the valve core in your Presta valve. Perhaps you removed it? It is the most important part, it must remain in the valve. If you no longer have it, you need a new one or a new ...
Vladimir F Героям слава's user avatar
13 votes

Quality check for donated tubes

Here’s what I would do when testing patched tubes: Inflate the tube outside of a tire just a little past the point where it starts to expand. Let sit over a night or two. If it’s still got air, you’re ...
Paul H's user avatar
  • 4,152
12 votes

What does vulcanizing solution in patch kits consist of? Can I buy it?

For those that are curious what the difference is between "rubber cement" and "vulcanizing fluid", here's a summary of the chemistry. The actual process of vulcanization of rubber (Thank you Charles ...
Andrew's user avatar
  • 2,277
12 votes

Why using a puncture repair kit instead of a new inner tube?

I think you answered your own question to a large degree, but probably cost is the big one for most people. Once one knows what they're doing with a traditional vulcanizing patch kit, most of the time ...
Nathan Knutson's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible