Josh0 Posted February 27, 2014 Posted February 27, 2014 What is a PSI? I only know Bars cos I was schooled in Metric. PSI x 0.0689 = Bar
Captain Fastbastard Mayhem Posted February 27, 2014 Posted February 27, 2014 or just 0.07 - makes it far easier...
droo Posted February 27, 2014 Posted February 27, 2014 What is a PSI? I only know Bars cos I was schooled in Metric. I know bars cos they sell beer. In pints, which aren't metric. Or even imperial, cos they're smaller. Weird.
Captain Fastbastard Mayhem Posted February 27, 2014 Posted February 27, 2014 I know bars cos they sell beer. In pints, which aren't metric. Or even imperial, cos they're smaller. Weird. A pint that isn't a pint 'cos it's not 572 ml. Not even the pint cans are pints, 'cos they're 550ml. Quarts arent' even the same - 750 vs 660. Sigh. Too much for my frazzled brain. A bar is something I wish I was at right now...
openmind Posted February 27, 2014 Posted February 27, 2014 At low pressures, even 1 psi makes a difference, especially on a high-volume tyre. My front tyre is a 2.4 and I run it at 17 psi. Back tyre is a 2.25 and it runs at 20 psi. They feel equally hard - goes to show that you need less air in even a slightly higher volume tyre. And that's on 19mm wide rims (old Arch). If you run 21mm (e.g. Arch EX) you'll need even less as the wider rim increases the tyre volume. If I know I'm going to do a bit more rock garden stuff, I'll add 1 or 2 psi and can clearly feel the difference. The pressures may seem low but I think my digital gauge under-reads at low pressures so they're probably more like 20/23 psi (though it matches my floor pump gauge exactly at 100 psi). Also, I'm an XC weanie and pick my lines carefully, so for enduro you prob want a bit more air.
Hairy Posted February 27, 2014 Posted February 27, 2014 Low Pressure Setting, max traction / slower rolling and tyre squirms a littlehttp://sromusic.com/images/mike_this_much.jpg Medium Pressure Setting - Best all roundhttp://blogs.telegraph.co.uk/news/files/2011/09/Schroeder.jpg High Pressure Setting - Tar riding http://images.sodahead.com/polls/000576937/polls_negroponteafp_1224_52929_answer_1_xlarge.jpeg
Craig Stubbs Posted February 27, 2014 Posted February 27, 2014 Openmind...im sure you've got some errors in there man. At 1.2 - 1.4 bar, your tyre will either burp off or pinch flat at every corner or obstacle. Its virtually a flat tyre. And given that you mention XC, will have rolling resistance from hell
openmind Posted February 27, 2014 Posted February 27, 2014 Openmind...im sure you've got some errors in there man. At 1.2 - 1.4 bar, your tyre will either burp off or pinch flat at every corner or obstacle. Its virtually a flat tyre. And given that you mention XC, will have rolling resistance from hellWrong on both counts - I've been training and racing on that setup for nearly four years without a single puncture or burp (I weigh 80kgs). And softer tyres roll faster - do your research. Note that I said that my gauge under-reads, so my quoted pressures are probably 3-5 psi under the actual pressure. I should also have said that I run 29" wheels which can tolerate lower pressures than the equivalent tyre on a 26" wheel (because there is more air in the tyre as a whole). From experience the wheel size difference is worth about 4-5 psi. Perhaps the actual point I'm trying to make is that you should take all factors into account when setting your tyre pressure - type of tyre, tyre size, wheel size, rim width, riding style, roughness of surface and rider weight. Don't just go for 30 psi because someone else does. They could be riding a 2.0 tyre and weigh 100kgs.
Iwan Kemp Posted February 27, 2014 Posted February 27, 2014 Bwhahaha... All that means is extra padding for the falls... So you're at an advantage 2 x cracked ribs to proof it doesn't!
Iwan Kemp Posted February 27, 2014 Posted February 27, 2014 ... And given that you mention XC, will have rolling resistance from hell http://www.schwalbetires.com/wider_faster_page
Hairy Posted February 27, 2014 Posted February 27, 2014 How long is a piece of string?This long http://newsimg.bbc.co.uk/media/images/46743000/jpg/_46743727_alan_davies_bbc512.jpg
Capricorn Posted February 27, 2014 Posted February 27, 2014 wanna run low-low pressures without most of the squirm? Try the Super Gravity range of Schwalbe tyres They are fantastic in that regard. Given the recent reveal of a dual chamber tyre system from Schwalbe, it is clear Super Gravity was a stepping stone to that objective.
nolipoli Posted February 27, 2014 Posted February 27, 2014 I like to land sideways a little bit on jumps, so I run the rear at 2.5bar(35psi?) and the front at 2.0bar(28.5psi?).Even with that pressure in the rear I still get the occasional little burp if I land funny.Tyres are 2.25 Nobby Nics.
didi Posted February 27, 2014 Posted February 27, 2014 Geax has a app for tyre pressure.It is a good reference pointhttp://www.geax.com/download/app/ CheersDion
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