[Closed] Noiw heres a strange one - cant get any tyres to inflate above 2.1...

XM401 is only 22.5mm wide internally as far as I remember - perhaps the brands have based the sizing on wider rims of approx 30mm width like an XM481?

Tyres routinely come up undersized though.

any suggestions?

Stop measuring, or use the magic ruler tyre companies do.

. these supposedly can handle a 2.6 tyre.

This is nothing to do with the width achieved when inflated, its to do with how wide tyre is likely to seat and remain on the rim.

thanks

So you've tried four tyres that are all more-or-less the same stated width and you're surprised that they're all more-or-less the same measured width?

I thought he meant they all popped off the rim at 2.1 bar.

Why does the actual width of the seated tyre matter that much?

I'm clearly not understanding this...all 4 tyres have gone about 2.1...

Are you talking pressure or width? If width, that isn't a surprise as tyre manufacturers all measure in different ways (and probably use different rim widths so everything changes).

If tyre pressure, is the valve absolutely clear and if you are using inserts are you sure they aren't blocking stuff?

Hmmmmm, you're right about this being a strange one!

With 22.5mm rims the tyres are probably a bit "light bulb" shaped. Measure the height from the rim to the tread its probably closer to the stated width.

You shouldn't actually have any issues with 2.3" / 2.4" tyres on rims this size - BITD we all used to run 2.1 and 2.2" tyres on 17mm rims - but i'm not surprised they come up a bit narrow.

That's just tyres. (Almost) No tyres measure the true width. Yes they'd be wider on a 30mm rim but they'd all measure roughly the same.