I did a bit of bush track driving this Easter in the Grampians NP. I still have my original XT tyres, 215/55/R17 so I was a bit hesitant to drop the pressure that much. Ended up dropping it to 32psi (from 36psi) in fear that anything lower than that could result in a tyre coming off the rim... As the gravel there can get a bit chunky, the ride was very bumpy.
2 Questions:
1) Does anyone know when low pressure is too low? Specially when the tyres in question are low profile already, so not much wall to flex... This would come in handy as I would like to do a bit of sand driving next (following Kevin's suggestions and taking a shovel).
2) In large/chunky gravel, is it better for the car to go real slow (30kmh) and wear the bumps out or power along (50-60kmh) and get a slightly better ride?
Just points for further discussion I guess...
Cheers,
Pedro.
don't worry too much about your tyres bagging out with any profile
true the more profile a tyre has the more it will bag @ the side with low PSI
but the main idea behind lowering PSI is that you create a longer foot print
longer foot print = better floatation = traction = further along the track or beach