Spare Tyre - 420kPa

[Shull]

Just now went to check on my spare tyres and top up air(if needed)..saw the pressure..420kPa..wu ya boh? thats double of what we usually pump in normal tyres leh leh..

 

any idea what makes spare tyres need so high a pressure?

[Latioboy]

i thought the spare tyres are kept in the compartment for dunno how long.. so maybe its set at 420 .. and since tyres naturally deflate by themselves, so.. by the time you use them, at least its not too under inflated...

[Mach]

Space saver spare is it ? These need much higher pressure as they are much skinnier.

[Boyboy]

Pressure = force over area.

 

for those space-saving spare tyre, smaller area (contact patch), but force need to be the same (still support the weight of the car).. so pressure higher

 

i use a bicycle pump to pump my spare.. cos the volume is small, and the pressure so high, i dun quite trust the kiosk pump to handle it. bike pump can handle more than twice the max pressure of petrol kiosk pump..

[Boyboy]

ur explanation is wrong

 

like that can pump ur normal tyre harder, so can pump less often?

 

actually i used to do that

[Shull]

petrol kiosk pump can handle until 415kPa..that is 5kPa short of the recommended pressure..

[Fitvip]

Pump up to 415 and blow the last 5 to make up!

[Boyboy]

wha.. that's worse than i thought..

 

actually, i pump my spare higher than recommended pressure.. cos i know i wun take it out for a few months

 

the old style pumps can pump higher than the digital pumps. at least the gauge goes higher . but i wun take the risk.

[Octopus]

i use a bicycle pump to pump my spare.. cos the volume is small, and the pressure so high, i dun quite trust the kiosk pump to handle it. bike pump can handle more than twice the max pressure of petrol kiosk pump..

 

Huh? bicycle pump can pump till so high pressure??? Need alot of effort or not?

 

Perhaps I might consider getting a bicycle pump and keep in back booth for emergency case.....

[Boyboy]

can. bike tyres need way higher pressure. 420kpa (max for new digital pump) works out to abt 60 PSI. most decent bike tyre pumps can take up to 120 PSI.

 

i also have an air suspension pump. it reads 300psi max.. but so far i only need up to 165PSI

 

for emergency use, get a fix a flat and portable compressor pump types.. the bike pump is pretty useless other than to keep space saving spares inflated.

 

EDIT: effort is not a lot, but takes a long time . for normal tyre that is.. for my spare tyre, to pump up from 40PSI to 60 PSI takes abt 5 min. quite ok

Edited June 9, 2007 by Boyboy

[Fcw75]

Yes, Honda space saving tyre must pump to 420kPa. You go to the digital pump at Shell station, they can go much higher than 420kPa. The ones at Esso/Mobil cannot, maximum 415kPa only. Not sure about Caltex or SPC.

[Rally1000]

i use a bicycle pump to pump my spare.. cos the volume is small, and the pressure so high, i dun quite trust the kiosk pump to handle it. bike pump can handle more than twice the max pressure of petrol kiosk pump..

 

Bro can recommend the brand of pump you use?

[Boyboy]

use shell digital pump la, as bro FCw75 has recommended

 

i'm using parktool floor pump. but not cheap. abt 40+