…and powerchairs, too, of course.
I use Goop which costs £8.99 per 500ml bottle (postage for two bottles plus some bits and bobs was £4.99). OK, now you know where to get it don’t just click through – read on for details of how to install the stuff, and what care to take once it’s in there.
Any motorcycle dealer will have it, or a similar product, or you can use that link to get it online. Allow 250ml per tyre for all but the tiniest tyres, like pneumatic-tyred castors, where 125ml is fine (too much is better than too little). Manual wheelchair tyres (and cycles), take 125ml.
I also found this sealant for an extremely optimistic £25 per bottle (size not given), plus £8 per bottle postage. They say there’s enough for 4 wheels, so that should be a litre. Still hugely overpriced, though, considering a litre of Goop is £17.98. And £8 for postage? No way.
In the past I’ve used other sealants, apart from Goop. Oko is very similar in operation and price, and also available from motorcycle dealers or online bike accessories websites. Slime is, in my view, not up to it for scooters and powerchairs.
When installing sealant, move the machine so the tyre valve is at the ten o’clock or two o’clock position (instructions on the bottle say eight o’clock, but that’s for motorcycle tyres with a much larger volume, ten or two will ensure the sealant doesn’t pool around the valve), remove the valve core and install the sealant as per the directions. Then attach the pump and give it a couple of strokes to blow any sealant away from the valve, then take a few cotton buds and clean out the valve stem before replacing the valve and re-inflating the tyre.
Sealant also helps tyres to retain their pressure better (even without a puncture, tyres will slowly deflate), but, no matter how careful you are, there’s always a risk sealant will eventually block your pump or your pressure gauge. I get around this by fully deflating the tyre then pumping it up to the required pressure, using the gauge on the pump, that way there’s no risk of even the tiniest squirt of sealant when you attach the pump, and keeping the pump running while you disconnect it from the valve.
You may also find, eventually, that the valves can get clogged with sealant, making it hard or impossible to pump up the tyre. If so, remove the valve (look out for a squirt of sealant as you do so – catch it in a cloth), and either replace it with a new one or pick out the sealant with a needle and put the thing back. Really, a new one is cheap enough not to bother with cleaning the old one (usually in boxes of 4 – try Halfords or Motor World).
And on the subject of valves, replacing the standard plastic valve cap with a metal one will give you a far superior seal, and you can get some very nice ones if you fancy tarting up your wheels a little. See this page.
And that’s about it. Just fit it the sealant and forget it, unless you get a truly catastrophic puncture. Then, when you come to replace your inner tube, or your tyres if they wear out, gaze in amazement at all the punctures you never even knew about. This stuff really does work.
One final thought, though. Given that many mobility scooter and pretty much all powerchair users are, well, disabled, isn’t it high time manufacturers sourced puncture-resistant* tyres or, at least, routinely installed sealant at the manufacturing stage?
*No such thing as puncture-proof, except when using a solid insert for your tyres. Be aware, though, that if your machine has no suspension, you’ll get a considerably harder ride. If you have suspension, though, they’re worth a try.