"Youll probably find that the above bike uses 26 1 3/8" rims & tyres." Perhaps Not. ! I have a Marlboro cycle which had a 26 x 1 1/4 wheels , ( it lost the back & got a common 26 x 1 3/8 , which is too fat for the frame). The larger rim, smaller tyre 26 x 1 1/4 is much rarer , but was it the wheel of choice for 1970/80s Marlboro ?. ( PS 26 x 1 1/4 is very different to 26 x 1.25)
"Youll probably find that the above bike uses 26 1 3/8" rims & tyres." Perhaps Not. ! I have a Marlboro cycle which had a 26 x 1 1/4 wheels , ( it lost the back & got a common 26 x 1 3/8 , which is too fat for the frame). The larger rim, smaller tyre 26 x 1 1/4 is much rarer , but was it the wheel of choice for 1970/80s Marlboro ?. ( PS 26 x 1 1/4 is very different to 26 x 1.25)