Tire Pressure?

[shanneba]

I see for 2021 HD has added a tire air pressure "adjustment" to the listed cold tire pressures based on ambient air temp for both before and after riding.

AMBIENT AIR
TEMPERATURE
MOTORCYCLE NOT RIDDEN FOR 2 HOURS OR MORE: ADD TO FRONT AND REAR PRESSURES IN TABLE
20 °C (68 °F) or less 0 kPa (0 psi)
26 °C (79 °F) 7 kPa (1 psi)
31 °C (88 °F) 14 kPa (2 psi)
37 °C (99 °F) 21 kPa (3 psi)
42 °C (108 °F) or higher- 28 kPa (4 psi)

MOTORCYCLE RECENTLY RIDDEN: ADD TO FRONT AND REAR PRESSURES IN TABLE
20 °C (68 °F) or less 34 kPa (5 psi)
26 °C (79 °F) 41 kPa (6 psi)
31 °C (88 °F) 48 kPa (7 psi)
37 °C (99 °F) 55 kPa (8 psi)
42 °C (108 °F) or higher- 62 kPa (9 psi)


2021 HARLEY-DAVIDSON® OWNER'S MANUAL: SPORTSTER® MODELS

[Bone]

Originally Posted by shanneba

I see for 2021 HD has added a tire air pressure "adjustment" to the listed cold tire pressures based on ambient air temp for both before and after riding.



AMBIENT AIR

TEMPERATURE

MOTORCYCLE NOT RIDDEN FOR 2 HOURS OR MORE: ADD TO FRONT AND REAR PRESSURES IN TABLE

20 °C (68 °F) or less 0 kPa (0 psi)

26 °C (79 °F) 7 kPa (1 psi)

31 °C (88 °F) 14 kPa (2 psi)

37 °C (99 °F) 21 kPa (3 psi)

42 °C (108 °F) or higher- 28 kPa (4 psi)



MOTORCYCLE RECENTLY RIDDEN: ADD TO FRONT AND REAR PRESSURES IN TABLE

20 °C (68 °F) or less 34 kPa (5 psi)

26 °C (79 °F) 41 kPa (6 psi)

31 °C (88 °F) 48 kPa (7 psi)

37 °C (99 °F) 55 kPa (8 psi)

42 °C (108 °F) or higher- 62 kPa (9 psi)





2021 HARLEY-DAVIDSON OWNER'S MANUAL: SPORTSTER MODELS

Nice, good info and a smarter way to approach it.

[Tomcatt]

Starting ("cold") pressures change 1 psi per 10° F change in ambient air temp
Hot ("after ride") pressures should be starting pressure + 5 psi.
You adjust starting pressure to get that 5 psi rise.
Higher starting pressures result in less rise.
Lower starting pressures result in more rise.