Polo Bikes

Please show where all the light grippy 26" tyres are.

i ride a continental sport contact: http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/city/citytyres/sportcontact/sportcontact_en.html
probably the lightest you will get

bigger patch is more grippy ennit

not at all

softer compound is more grippy too

mostly true, softer tires often have higher frictional coefficients

more grippy will usually mean higher rolling resistance

not necessarily

Anyway, the long and the short of it is that no-one has been able to convincingly answer why some tires are more grippy, whether a smaller contact patch is more grippy than a bigger one etc etc. Probably because it's seriously complicated physics & also tire grip is serious trade secret stuff.

this is quite simple in theory:

that is: "maximum sideway friction" equals "frictional coefficient" multiplied by "force that is applied vertically to the ground".
the frictional coefficient is the only part where the tire influences this equasion. it does NOT depend in any way on: tire surface, tire pressure, etc. it is a value that is determined in experiments (!) considering the two materials that are in contact, and outer influences, like lubrication (eg. water). rubbercompound x and tarmac have a certain coefficient. rubber compound x and wet tarmac have another coefficient. and so on.

in reality, a bigger tire or less pressure and therefore a bigger surface might help you if there is debris on the court that makes you lose contact with the ground when you ride over it. but, as long as your tire is in contact with the ground somehow, surface doesn't matter for grip

if you want more grip you have one option. get another rubber compound. a bigger tire won't help (at least not in theory, thats for sure)

rolling resistance is even more experimental stuff than friction, i don't know enough about it to really beeing able to explain everything right. main thing is: rolling resistance increases exponentially as pressure gets lower. probably because: if you have lower tire pressure, your tire doesn't just roll in clean contact to the ground, but it gets warped constantly. this needs energy, which is then mostly transfered into heat.

hope my poor technical english ins't too confusing