Video summary

Are Wider Tyres REALLY Better on eBikes?

Main summary

Key takeaways

Science and Nature

Scientific concepts / nature-physics phenomena mentioned

  • Rolling resistance vs tire width

    • Wider tires can show lower rolling resistance at a given pressure (“what the science tells us”).
    • This is cited as a reason tire sizes have increased in cross-country MTB racing for efficiency.

  • Hoop stress (tire casing mechanics)

    • A concept suggesting that a wider tire running at lower pressure can produce similar casing tension / feel as a narrower tire at higher pressure.
    • Lower pressure increases:
      • Comfort/compliance (the tire deforms more)
      • Grip, because the tire deforms into the trail
      • Contact patch effectiveness (the tire “squishes” more onto the ground)

  • Tire deformation and grip on rough terrain

    • More deformation on rocky/rooty/slippy surfaces is linked to more grip, since the tire conforms better to irregularities.

  • Rotating mass / performance trade-off

    • Wider tires add weight at the edge of rotation, which can affect ride feel and responsiveness (described as a form of rotating mass effect).

  • Casing tension and pressure matching

    • The video attributes the ability to run lower pressures on wider tires to “casing tension.”
    • It also references online equations/calculators used to compute pressure targets across different tire widths.

  • Tire blow-off (“burping”) / bead retention risk

    • Running too low pressure on wider tires can increase risk of:
      • Burping (bead pulling off the rim and releasing air)
      • Instability/deformation that could contribute to a crash

Methodology / test procedure (as described)

  • Use two tire width configurations on identical wheels:

    • Standard: 2.4 front + 2.4 rear (Schwalbe Magic Mary)
    • Wider: 2.6 front + 2.8 rear (Schwalbe Magic Mary)
    • Wheels: identical Industry Nine Enduro carbon wheels

  • Run on local technical trails with mixed conditions:

    • Rocky/rooty/slippy singletrack sections (up and down)
    • Fire-road/drag-climb climbs
    • Mix of dry and wet, hard and soft ground

  • Timing and comparisons:

    • Use a Garmin MTB Edge
    • Set timing gates/split times for climbing, descending, and surface types
    • Compare:
      • Overall lap time and section split times
      • Subjective feel (compliance, grip, “floatiness”)

Key experimental results (as stated)

  • Weight difference between setups

    • 2.4/2.4 setup: 2260 g
    • 2.6/2.8 setup: 2425 g

  • Overall lap time

    • 2.4s: 20:49
    • 2.6/2.8: 21:14 (about 25 sec slower)

  • Section trends (not fully conclusive)

    • Wider tires slower on:
      • Fire-road climb: ~15 sec slower (biggest climb)
      • Tech downhill: ~4 sec slower
      • Tech climb: ~7 sec slower
    • Wider tires faster on:
      • Mellow fire-road climb + flat: >6 sec faster
      • Short smooth final descent: ~1 sec faster

  • Overall conclusion from the rider’s preferences

    • Prefers 2.4” tires as the best compromise for technical riding in mixed conditions.
    • Suggests possibly using wider (2.6/2.8) in summer and 2.4 in winter (softer ground), but notes this would require two sets of tires.

Featured researchers / sources

  • No specific researchers are named.
  • Mentions “online equations and calculators” for pressure matching across tire widths, but does not cite particular sites or authors.

Original video