So I’m looking on the Schwalbe website for some tires for my 29er commuter. They sometimes have wheels in a 28″ size… can someone more knowledgeable explain this please?

Also as I’m asking stupid questions can I run 700×45 on a 29er rim?

28″ = 700c = 29er.

Yes, so long as the internal rim width is lower than 26mm.

Thanks. I suspected as such but nice to have a bit of confirmation {awaits someone else saying opposite}

Nah he’s correct :-). Long winded explanation…

28″ 700c and 29er are outer diameter measurements with a chosen size tyre when they were deciding the standards. A 29er wheel with 2″ tyre is about 29 inches if you measure it. The ETRO number is the safest to go by as it’s the inner diameter of the tyre, 28″ 700c and 29er are all 622mm ETRO which given the amount of tyre widths that go on the same wheel nowadays is an easier way of doing it.

An old 27″ road wheel is bigger than 28″, the ETRO is 630mm which makes more sense.

There is the older 28″x1.5″/700B with a 635mm ETRTO which was commonly used on old British/Indian ‘roadster’ style bikes with rod brakes. Confusingly the Germans call 700c 28″ for road bikes whilst 29″ was adopted for MTBs.

Back to your original question, yes a 700Cx45 will fit a 29er rim