A 37-590 bike tyre is usually sold as 650x35A or 26x1 3/8. It is common on vintage city bikes, classic French-style utility bikes, some mobility wheels and restorations where keeping the original rim matters. The reliable compatibility mark is ETRTO: approximately 37 mm wide on a 590 mm rim.
650A, 650B and 650C are not interchangeable
The trap is the letter after 650. This guide is about 650A / 590 mm. Modern 650B tyres are usually 584 mm and will not fit a 590 mm rim. Other 26 inch tyres can be 559, 571, 584, 590 or 597 mm. Read the old sidewall and keep the second ETRTO number identical.
Choosing between Delta Cruiser, Marathon and Greentyre
For a classic town-bike look, a Schwalbe Delta Cruiser in cream or black keeps the bike visually close to its period. For regular commuting or rougher roads, Marathon GreenGuard or Marathon Plus adds more puncture-protection focus, with extra weight and a firmer feel. A Greentyre City solid tyre removes the tube but is a specialist choice: check the listed 19-21 mm internal rim-width requirement and expect a different ride feel from an air tyre.
Tube and valve checks
Use a tube that explicitly covers 590 mm, such as a 650A/B/C tube with an ETRTO range including 37-590. Then check the valve. Many older rims are drilled for Presta or Woods/Dunlop style valves, while some utility wheels use Schrader. Do not force a valve through the wrong rim hole.
Clearance on older frames
A 37 mm tyre is modest, but older mudguards, calliper brakes and steel frames can have tight spaces. Check the brake bridge, fork crown, stays and mudguard line after inflation. A reinforced tyre can stand taller than an old worn tyre, so leave clearance rather than judging by the uninflated casing.
Shop 37-590 tyres from 1Bike
1Bike lists pneumatic and solid 650x35A options, plus tubes with suitable ETRTO ranges. Start from the sidewall, then compare appearance, puncture protection, rim-width constraints, valve and daily riding comfort.
