Are Wider Tyres REALLY Better on eBikes?

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

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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”)

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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.

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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.