DURO 26 x 1 3/8 Thorn Resistant Bicycle Inner Tube – 33mm Schrader Valve, Removable Core.
Item Type: Bicycle Inner Tube
Tube Size: 26 x 1 3/8
Width Equivalent: 1.375 in
Construction: Thorn-resistant / heavy-duty butyl rubber
Designed Use: Street, cruiser, and vintage bicycle applications
Brand: DURO
Valve Type: Schrader (car-style valve)
Valve Length: 33mm
Valve Angle: Straight (0°)
Valve Core: Removable
Valve Stem Finish: Smooth
✔ Compatible with most standard bicycle pumps designed for Schrader valves
✔ Removable core allows easier service and sealant compatibility (where applicable)
Fits Tires Marked: 26 x 1 3/8
This tube is intended ONLY for bicycles using 26 x 1 3/8 tires, which are NOT the same as 26 x 1.75, 26 x 2.0, or standard MTB 26" tires.
26 x 1 3/8 tires exist in two different rim standards:
ETRTO 590 (650A)
ETRTO 597 (Schwinn / S-6 / EA3)
➡️ Buyer must confirm the ETRTO number printed on their tire sidewall before purchasing.
This tube is designed specifically for 26 x 1 3/8 applications—matching the correct ETRTO size is essential.
Vintage and classic cruiser bicycles
Older Schwinn-style cruisers using 26 x 1 3/8 tires
Select vintage roadster and city bikes equipped with 26 x 1 3/8 (650A or Schwinn-type) wheels
Middleweight and heritage bicycles originally designed around narrow 26" rims
(Not compatible with modern 26" mountain bike wheels)
Thicker rubber construction compared to standard tubes
Helps reduce punctures caused by:
Thorns
Glass
Road debris
Ideal for riders prioritizing durability over ultra-lightweight performance