TIRE PRESSURE INSTRUCTION

Ideal tire Pressure To Maximize Performance (tubular and clincher)
Starting with 110 PSI adjust the combination of the corrections below up to 130 PSI maximum or down to 90 PSI minimum according to the following rider and venue attributes:

   +10  Large rider (>170lb rider) - also advise wider tires
   +10  TT narrow tires (20mm clincher, 19mm tubular)
   +10/+20 Specialty suspension frame (beam seat, suspension fork)
   -10  Small rider (<140lbs rider)
   -10  Wet conditions - also advise wider tires
   -10  Rough terrain - also advise wider tires
   -10  Challenging handling (mountains, cornering, Crits, etc.)
   -10  Less experienced riders (improves handling, comfort)

We find absolutely no performance reason to inflate tires beyond 130 PSI (9 BAR). 
After extensive and careful measurement of tire rolling resistance (at a precision of 1/10,000 of wheel energy), We find rolling resistance  losses to be significantly less than 1% of the energy in the entire wheel system.  This is an energy estimate well below the other performance factors effecting tire pressure choice.  Modern tire materials have become so efficient and elastic that historical notions of the importance of tire pressure are simply incorrect.  Also note that tire brand differences in rolling resistance are similarly tiny versus more significant factors such as: tire defect rates, tire roundness, tire traction, tire weight and strength, and price value.  Be warned that there are many confusing and incorrect marketing messages from tire manufacturers, distributors and sales channels that do not completely understand the difference between tire pressure limits and real world application of products.

Our measurements find the expected differences in rolling performance between 650C and 700C wheels (700 are slightly better) and between narrow 19mm tires and wider 21+mm tires (wider is slightly better).  But again, we find that the magnitude of these are easily secondary to the other factors in choosing ideal wheel size (rider fit, aerodynamics, acceleration) and tire width (aerodynamics, comfort, traction, handling).  

We find many reasons not to inflate your tire beyond the 130 PSI limit.  Heavier riders or riders on suspended bicycles can ride at the 130 PSI limit while lighter riders should ride at 90 to 110 PSI.  The Negative consequences of high inflation pressures include: (1) elimination of the principal shock absorber on a bicycle significantly impacting rider fatigue and equipment wear, (2) degradation of handling from the smaller contact patch (increasing slip rates and side wash out), (3) loss of traction (loss of rear wheel acceleration, and braking skids) , (4) marked increase in flat tires (less tire to road conformance, greater puncture load behind road hazards), and (5) more rapid catastrophic flat tires.  If you demand high inflation pressures consider our tubular composite wheels which work with tires rated to 220 PSI, however exactly the same advice pertains to tubular tires.  Do not over-inflate tubular style tires, for the same reasons, it offers no performance benefits and carries the same detriments of increased shock, and worse handling, traction and flatting.

 

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