Q. I notice one of the valves on my bike tyres is at a funny angle. Does this matter? The bike seems to ride OK.
A Yes, it is important. The valve should point directly at the centre of the wheel, that is, at right angles to the rim.
This is vital because the valve, which sticks out so that you can pump up the tyre, is basically a metal tube glued into the side of the rubber tube inside the outer casing. Such a joint is a bit delicate because joining two different materials together is technically difficult, and therefore inclined to be weak. The tube is like a long balloon and when you pump the tyre up it can’t stretch like a party balloon does because of the stiff rubber of the outer tyre, so the air becomes pressurised and we can ride over bumps etc.
If that valve is bent over at an angle it puts stress on the join with the tube and can eventually tear. Then the air leaks out but it is not like a puncture that can be mended, the tube is ruined and you’ll need a new one.
So, why does this happen? Well, when the tyre is fully inflated the pressure between the tube, the tyre, and the rim of your wheel locks them all together, nice and tight. If the tyre gets soft because the air has leaked out over time and you continue to ride it ( perhaps you haven’t used the bike for a while and didn’t check the pressures before you started off) the gap between the tyre and the wheel rim isn’t so great and with braking etc. The drag of the road pulls the tyre round a bit and the valve gets distorted.
If you just pump it up the tube will be at that funny angle and risk being torn out of the tube.
It’s fairly easy to put right though, you’ll be pleased to hear, let the air out of the tyre and with one hand squeeze the tyre and tube at the sides, while with the other hand push the wheel away from the direction of tilt. It will only be a fraction of an inch, but you’ll see the valve move to the right angle position it needs to be in. If you’ve gone too far just pull the other way.
Once the valve is right, pump up the tyre until it’s hard and it will stay there, and you can be ready for your next ride.