non-reversible temperature stickers

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Rim Temperature Study

Anecdotal evidence suggests that rims that get hot are more likely to release a tire, resulting in blowoff. The maximum temperature experienced by a rim used as a braking surface depends on many factors, and the rim temperature at which a particular tire will creep off the rim varies by factors that are not easily quantified.

What this study attempts to do is to record new "high temperature events" observed on one of my two bikes, noting various conditions under which the observation was made, the maximum temperature reached, and whether or not the tire blew off the rim. As data is added to the table below, I hope at some point to be able to conclude a maximum safe operating temperature for a particular combination of conditions, and perhaps a maximum safe operating temperature in general.

The rims I use are equipped with non-reversible temperature sensing labels from Omega Engineering. A non-reversible label identifies the highest temperature experienced and does not reset as the measured object cools down. It is a "peak reading" meter. Table data in the "Maximum Rim Temperature" column are given as an interval (X, Y), where X is the highest temperature dot that turned color, and Y is the next dot on the strip that did not turn color. Where there was no "next dot on the strip", Y = '?', which means that the maximum temperature is not known, only that it is higher than X. Data in the other columns should be self-explanatory.

Bike RiddenTotal Mass (kg)Front or Rear WheelRimTireTire Pressure (psi)Tire Age (years)Tire Distance (km)Ambient Air Temperature (C)Maximum Rim Temperature (C)Blowoff?Other Notes
Power Pursuit F2132RearRitchey OCR-Pro 559, ca. 2003Ritchey Tom Slick 559x36 (kevlar bead)75130022(121, 127)NoDescending the backside of Mt. Hamilton
Power Gold Rush127FrontSun L14 406Schwalbe Kojak 406x32702650019(104, ?)NoDescending the north side of Hicks Rd.
Power Pursuit F2132RearRitchey OCR-Pro 559, ca. 2001Kenda Kwest (Hi-Pressure) 559x387505612(143, 149)NoDescending the backside of Mt. Hamilton
Power Gold Rush127FrontSun L14 406Schwalbe Kojak 406x32702670018(116, 121)NoDescending Sierra Rd. amongst crowds slowly, after ToC, Stage 4
Power Gold Rush127FrontSun L14 406Schwalbe Kojak 406x32702675021(127, 132)NoDescending Redwood Gulch Rd. carefully, using more front brake than usual
Power Pursuit F2124FrontBontrager Maverick 406Schwalbe Kojak 406x32902250035(82, 88)NoDescending the east side of Mt. Madonna Rd.
Power Gold Rush127FrontSun L14 406Schwalbe Stelvio 406x2890830030(?, 132)YesDescending Montebello Road carefully, using more front brake than usual, coming to a complete stop at the sensor cutout to activate the gate. The tire blew off while I was stopped trying to trip the sensor. This tire can be mounted on the rim without using tire levers.
Power Gold Rush127FrontSun L14 406Schwalbe Stelvio 406x2880840020(82, 88)NoDescending Alpine Road (west)
Power Gold Rush127FrontSun L14 406Schwalbe Kojak 406x32703150020(93, 99)NoDescending Upper Rock Creek Canyon Rd.
Power Gold Rush136FrontSun L14 406Schwalbe Kojak 406x32703770020(116, 121)NoDescending On Orbit Lane
Power Pursuit F2132RearRitchey OCR-Pro 559, ca. 2001Kenda Kwest (Hi-Pressure) 559x38751338012(149, 154)NoDescending the backside of Mt. Hamilton
Power Gold Rush127FrontBontrager Maverick 406Schwalbe Stelvio 406x289094020(149, ?)NoDescending Mt. Umunhum Road
Power Gold Rush127FrontBontrager Maverick 406Schwalbe Stelvio 406x2890919015(88, 93)NoDescending Tunitas Creek Road
Power Gold Rush127FrontVelocity A23Ritchey Rov'r 406x34751118030(93, 99)NoDescending Alpine Road (west)
Power Gold Rush127FrontVelocity A23Ritchey Rov'r 406x34751130025(121, 127)NoDescending Kings Mountain Road (riding brakes behind slower traffic)
Power Pursuit F2125RearRitchey OCR-Pro 559, ca. 2001Kenda Kwest (Hi-Pressure) 559x387502533(?, 154)YesDescending west Alpine Road. One layer of Velocity Velotape replaced the thicker, cloth Velox rim tape.
Power Pursuit F2125RearRitchey OCR-Pro 559, ca. 2001Kenda Kwest (Hi-Pressure) 559x3875115040(116, 121)Yes*Descending Kings Mountain Road. *Failure was not a blow off but a tear at base of the tube's valve stem. I suspect the tire slid circumferentially on the hot rim.
Power Gold Rush119FrontSun L14 406Schwalbe Kojak 406x3270180025(143, 149)NoDescending On-Orbit Lane
Power Gold Rush127FrontSun L14 406Schwalbe Kojak 406x32701500032(154, 160)YesDescending Upper Zayante Road; tire was loose enough to be re-mounted without the use of levers.
Power Gold Rush127FrontVelocity A23Panaracer Minits Tough 406x32800198030(138, 143)NoDescending Jamison Creek Road
Power Gold Rush119FrontVelocity A23Panaracer Minits Tough 406x3280143005(?, 143)YesDescending Summit Road, Mt. Diablo; tire was an extremely tight fit.

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