24x1" tires
 

I'm buying a 45cm Bridgestone 550 from a friend of mine to build up for my girlfriend. It has a 24x1" front wheel, which leads to my question. I ordered a yellow Primo wheelchair wheel from a medical supply website, labeled as 24x1" (540mm). When I received the tire, it looked a little large, so i did some research. According to Sheldon Brown, the ISO for a 24x1" is 520mm. All fractional sizes for 540mm tires are slightly larger than 24x1" (I confirmed this on the chart provided by NYCBikes). Although the website labeled the tire I got correctly at 540mm in the fine print, I think the headlining 24x1" measurement was a mislabel.

Am i right in assuming this? And more importantly, will this size difference make the rim and tire incompatible?

Yes the fact that both ISO 520 AND ISO 540 rims get called 24" and 24x1" at that is a PAIN but it doesn't stop there. ISO 507 and 547 are both called 24" as well. No the tire isn't compatible. Put it down to a learning experience. Actually the only ISO 520 tires I've seen were labeled 520 x 23c so there is no consistency that I can see.

Regards, Anthony

Should i try to get a refund based on their labeling, or should I just forget about it?

Also, does anyone know where to find a good selection of 24x1" 520mm tires?

You could always try for a refund but I'm not sure if your case is strong because they did list it as ISO 540. Put it on eBay. Schwalbe make good quality ISO 520 tires and apart from that the only other ones I know of are cheap OE tires.

Regards, Anthony