Advice: inflating wheelchair tyres

[ciphergoth]

A recently wheelchair-using friend is finding that a bicycle pump doesn't seem to fit her wheelchair tyres, and they are slowly getting flatter and flatter. She mentions that she once had the tyres inflated from the compressed air at a garage, but I know that if I take the chair to a garage they will have no idea what to do or whether I'm in danger of blowing the tyres up. Does anyone have any advice? Thanks!

Comments

[drdoug.livejournal.com]

Don't use a garage air pump! (Unless the wheelchair tyre manufacturer says it's Ok.)

I know this is a big mistake for bike tyres - there's a serious danger of the tyre blowing up in your face.

It's down to physics. It's true that car tyres are typically inflated to lower pressures than bike tyres. But it's not just about pressure. Car tyres hold a lot more air - simply because they're so much bigger. So a garage air pump - designed for much larger car tyres - will tend to pump far too much air in to a bike tyre, running the risk that it'll overinflate before the pressure sensor has time to cut off the air supply. You might get away with it, but the pressure won't be accurate and you are running a serious risk you don't need to.

I don't have particular expertise with wheelchair tyres, but they look about the same size as bike tyres, so I very strongly suspect the same issues apply.

My top tip for bike tyres, which should work for wheelchairs, is a thing called a 'track pump'. It's like an ordinary bicycle pump turned on it's end, with a plunger on top like a cartoon bomb detonator and a pressure gauge built in. They tend to be a bit larger in air capacity than an ordinary bike pump, but the really big advantage is that you have gravity helping you on the compression stroke. It makes keeping tyres inflated to the correct pressure way, way easier. Whether this is any use for your wheelchair-using friend I don't know - probably depends on why they're using a chair and/or how they feel about getting someone else to do it for them.

[lovingboth]

Yep to all that.

If your bike pump doesn't fit, it's probably a Presta, and all track pumps will have one of those, as it's what Real Bicycle Tyres have.