Originally Posted by
operator
Read off the ISO number on the 1 1/8" tyres. If they are not 559 then they are not compatible. Most fractional sizes are not compatible with modern "decimal" sized tyres. Regarding width - the inflated width of the tyre profile should not be narrower than the rim. This is easily verified by visual inspection
As far as the ISO number, they are 559. I don't know why Conti uses fractions in the sizing on these, but they do. We had an LHT come in once with these tires and they were marked 1 1/8, and the BSD was 559. If you look in the QBP catalog they're listed as 559 and 26 x 1 1/8.