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Help! My Inner Tube is Defective
Nearly any bike shop owner (online or offline) will tell you one of the hardest yet most frustrating complaints to deal with is along the lines of this:
You sold me a tube and it’s defective.
The problem is, in nearly every case, that the tube is not defective but the installation techniques used were perhaps not the best. 99.9999% of all issues with tubes is human related – my money is on incorrect installation.
It’s not easy to tell someone they made a mistake without them taking offense – especially so when someone genuinely thinks they have not/would not make an error – but in this post I’ll try to explain what a few of the more common issues are, what the typical reason is for the problem and how to avoid the issue again next time… The purpose of this post is not to make you feel silly for making a mistake, but to try and help you understand why these things happen and how to avoid them in the future.
The Seams Are Tearing Away
These days tubes are made from factories with such high standards, this is no longer considered a manufacturing defect. This will for sure be due to improper installation.There are three likely scenarios:
- Incorrectly fitted tyre. Tube has escaped between rim and tyre under pressure. Action: Ensure correct fitting, inflate slowly whilst checking before inflating to correct pressure.
- Tyre bead is damaged or separating from tyre carcass. Action: Replace tyre.
- Tube damaged whilst fitting. Action: Don’s use tyre levers (or screwdrivers!) – peel the tyre over the tube using your fingers and thumbs only.
There is a Bulge in my Tyre / Tube
Again, this will almost certainly be from incorrect installation. A tube inflated outside of a tyre & rim and bulges and / or distorts, is not regarded as faulty. All tubes will expand, become distorted and bulge when inflated outside the constraints of a tyre correctly fitted to a rim. Tubes are mere “air proof wind bag”s, and are not intended to withstand pressure beyond about 14psi (1 bar) unless fitted to the appropriate tyre and rim combination. The maximum pressure is determined by the constraints of the tyre and rim. Recommended tyre pressure is embossed on tyre wall and should be adhered to within approx 10%.
NOTE: Rims also have a pressure rating, usually +100% greater than any tyre that is likely to be fitted to that rim.
Some temporary increased pressure beyond 14psi, thus exaggerating any distortion and / or bulging, may be required to assist in locating and repairing a puncture.
A tyre (fitted to a rim) that bulges on inflation is the result of:
- Poor tyre / rim combination
- Incorrectly fitted tyre to rim
- Incorrect rim-tape
- Damaged tyre / compromised construction of tyre carcass
- Tyre inflated beyond the manufacturer’s recommended pressure rating.
Leaking Valve (or close to the valve)
The most common reason for this is when the pump is attached to the tube’s valve, either in the action of attaching the pump to the valve, attempting to pump up the tube or (most commonly) when detaching the pump from the tube. Take care not to twist or bend the valve with your pump – this will cause leaky valves which are particularly annoying and cannot be repaired.
I Installed My New Tubes But Still Got a Flat!
If the flat occurred immediately (or very shortly) after you installed the new tube, it would be an installation issue. If the flat happened a while after, it would be a puncture. Unfortunately no tube (or tyre for that matter) could be ever known as being completely puncture-proof. Flat tyres are an unfortunate consequence of cycling. That said, punctures should not be happening too frequently. Be sure to check your tyres for cuts and glass, and don’t hit big potholes or gutters if you can avoid it!
Wrong Tools
Also worth mentioning is to make sure you are using the right equipment. Here’s a few tips worth mentioning when it comes to replacing your inner tubes:
- When taking the tyre off or putting it back on, never ever use a screw driver. NEVER.
- When taking the tyre off use tyre levers sparingly, although a fantastic tool they should normally be considered “last resort”.
- When re-installing the tyre back onto the rim, you shouldn’t use tyre levers. They may cause a “snake bite” flat and it’s a great way to break your tyre levers!
Practice Makes Perfect. (Nearly!)
Once you’ve worked out how to replace tyres and tubes on your wheel you’ll find it a breeze, a five minute job tops. If you know what you’re doing it’s easy, but if your skills are a bit rusty sometimes it does take a bit of patience (and sometimes some tough lessons) to become a master. But at the end of the day this is an important skill to know if you’re going to ride a bike, and everyone has to start somewhere.
That said, I admit to having blown out more than one tube recently when I was trying to fix a flat. And for the record, I’ve made all of the above errors and a lot more! Having done it hundreds, if not thousands, of times for more than half my life, it’s a bit embarrassing to stuff it up – especially when somebody else is watching! You’d think someone with a bit of experience would know not to much such a silly mistake when somebody else is peering over your shoulder, right?!?! However the good news is the price of tubes have dropped remarkably with the rise of online retailers such as us here at Mr Cycling World, and suddenly stuffing up a tube here or there isn’t going to break the bank like it used to. On to the next tube…
Finally…
I realise this post comes across a bit “in your face” compared to my normal writing style, but I do hope it is helpful to someone out there! Special thanks to my Dad, who some of you will know as a former bike shop owner for 35+ years, in helping write some of the above.
Remember: Happy riding.