bike tyres

Bike tyres
My current (push) bikes have tyres with widths of

1. 32
2. 35
3. 38

millimetres. I have had several tyres donated. I take the opportunity to rotate the sizes when I have to fix a flat tyre. Currently, the front tyre is being fixed. There were lots of very small stones embedded in the rubber and one that had penetrated the tyre. The usual water test does not reveal any obvious leak but the valve may not have been closed properly.