8.5x2 (50-156) Tube Straight / 45 degree [CST | Superbsail | JY-04]

• The 8.5x2" (50-156) tube with straight valve is common tube adopted on Xiaomi M365 and copies of.
• Typically paired with the common 8.5x2 (50/75-6.1) tyre which inflates to 8.5" diameter on a 6.1" rim, models of Xiaomi original M365 and subsequent models 1s, 2, 3, Pro, Pro 2 and Essential as well as copies such as Mearth S and eGlide Swift (by Kingsong), their D150 & G60. Also suits the relatively new 230x50 tyre on Xiaomi MI3, MI3 Lite & MI4 Lite.
• Available in choice of three variants with variances in weight (grams), subtle position of valve, and inclusion of nut & washer:
  • 97g CST (straight valve). Valve meets tube in the centre (middle). Also available in 45 and 90 degree.
  • Superbsail (straight captive nut). Nameplate 8.1/2x2 156 A 1.5 (45 degree 100 gram) and 2.0 (straight 120 gram). Valve meets tube offset from center (so not in the middle). Our most popular.
  • 140g JY-04 with captive nut and bevel washer. Valve meets tube in the center (middle).

Notes:

1. The first three product images show the CST 97g, next three the 120g Superbsail captive nut straight, last two images the 140g captive nut & washer version.
2. The 50 designation = 50mm inflated width (1.96"), 156 designation = 6.14 inches internal diameter, ideal for 6.1" rims.
3. The nut helps hold the valve in place, the washer provides optional stem support from the valve hole.
4. On the original M365, the motor hub (front) requires a straight valve. The non-motor hub wheel (rear) is typically 45 degree, but straight, 0 degree and shorter, near-90 degree valves can be used as rear has no motor hub.
5. The valve on the CST and Superbsail tubes sit slightly off centre, which may provide a favourable alignment with valve hole in the rim.
6. e-watts (France) regards the weight of 145g tubes (2.35mm thick) to be "twice as thick as the original offering inner tube". Standard "reinforced" inner tubes (1.70mm) weigh in at around 105 grams. Early, original inner tubes were (or originally were) 1.35mm (83 grams).
7. Will not suit Xiaomi 4 Pro which adopts 10" 60/70-7.0.
8. Fitting these is all about technique. Learn from the Pro's at e-Watts France: