Tyre pressure?

[Paul_C]

Hey Guys (and Gals),

In a lot of the reading i've been doing I've seen that everyone recommends checking (and filling) tyres when they're cold, so that the heat doesn't interfere with the pressure. I don't have a compressor at home, so pretty much everytime I want to fill my tyres I'm going to have to pop down the road at least 2km to the nearest servo - thus heating the tyres and spoiling my readings.

I have a handy dandy tyre pressure gage that I can apply to find the true cold pressure, but in order to fill I'll have to heat the tyres up.

Does heat in the tyres make _that_ much of a difference?

[MSTRS:Me]

Yes

[Sully60]

Depending on your bike, riding style, load it's carrying etc. you could get up to 6 psi increase pressure, this also depends on how far you've ridden. (if it's just around the corner you're probably ok)
Buy a good quality gauge,(Accugage all the way for me!) a cheap footpump from the warewhare if you live too far away from the gas station.

[short-circuit]

Depending on your bike, riding style, load it's carrying etc. you could get up to 6 psi increase pressure, this also depends on how far you've ridden. (if it's just around the corner you're probably ok)
Buy a good quality gauge,(Accugage all the way for me!) a cheap footpump from the warewhare if you live too far away from the gas station.

+1 Check at home with tyre pressure gauge and get yourself a footpump at Repco or supercheap for $30. TOO EASY

[Ralph]

+1 Check at home with tyre pressure gauge and get yourself a footpump at Repco or supercheap for $30. TOO EASY

What he said plus by doing this it gives you a regular consistant reading rather than using those crap ones at the servo where eveyone will give you a different result.

[vifferman]

Yep, what they said. I also carry a pen-type gauge with me (checked against my more expensive Accugage), as if you need to check your tyres away from home, service station gauges are often inaccurate.
BTW - having owned a VFR or two, you will find that for many tyre types running the front tyre at more than a couple of PSI lower than the recommended 36 psi pressure will cause the bike to be somewhat "wandery", due to steering geometry / weight bias. The rear tyre isn't quite so picky, so you can run that up to 4 psi lower. Note that if this is too low, this may lead to uneven wear or 'squaring off'.

[dipshit]

http://www.autoexpress.co.uk/product..._footpump.html

One of these from supercheap will be the best $35 you will have ever spent. (plus a separate gauge)

[xgnr]

FWIW

I use a cheapish gauge and top up with a Push bike pump (cos I ride a pushy eh ...)

However, last time I was down south I was talking to a guy who has a lot of experience and he was of the opinion that you need to check the change between cold and hot.

If the change from cold to hot is greater than 10% then the pressure (cold) is too low.

If it is less than 10% then too high

Logic being I guess that there are lots of variables about absolute values BUT the change is what is important with that tyre.

Cheers

Stu

[dipshit]

However, last time I was down south I was talking to a guy who has a lot of experience and he was of the opinion that you need to check the change between cold and hot.

Yep, but once you have worked out what pressures to run... you then still want to check and set them when cold.

[xgnr]

Yep, but once you have worked out what pressures to run... you then still want to check and set them when cold.

errr yes a logical next step

[Jerry74]

BP down this way at Rolleston has the computerised air meter, very accurate.

I just pop another 2 psi in each tyre for any long distance stuff.

[Owl]

I have a handy dandy tyre pressure gage that I can apply to find the true cold pressure, but in order to fill I'll have to heat the tyres up.

You could always take a cold reading at home, take your pressure guage with you and check pressure again at servo. Note the difference and adjust accordingly!

[Rodney007]

what tyres are you using to start with.......

[discotex]

It's simple really... Overfill them by a few psi on the way home.

Leave the bike overnight then check and lower using your gauge in the morning.

Or just use the same servo every time. If it's always after 2km warmup of gentle riding you'll at least be consistent if not 100% accurate. You're unlikely to gain more than 2psi if you ride like a nana.

Or just get a foot pump.

[Paul_C]

BTW - having owned a VFR or two, you will find that for many tyre types running the front tyre at more than a couple of PSI lower than the recommended 36 psi pressure will cause the bike to be somewhat "wandery", due to steering geometry / weight bias. The rear tyre isn't quite so picky, so you can run that up to 4 psi lower. Note that if this is too low, this may lead to uneven wear or 'squaring off'.

Yes, I've definitely noticed this one. It almost seems that depending on the day/weather/tyre pressure the front will want to go its own way by various amounts.

what tyres are you using to start with.......

I've got a Metzeler Z6 on the back which is probably at about 75% and a Michelin Macadam 100X on the front with maybe only 500km left. I'm going to get it replaced with a matching Z6 this payday.

By all accounts a foot pump is a way to go. I always thought that due to the size of the tyre a foot pump wouldn't provide enough pressure. But then again I have a road bicycle which push past 50 so 36 shouldn't be a problem.

Cheers for all of the advice!