Tyre pressures
 

whats best tyre pressures

the best psi values are those above 0.

seriously now... this is quite easy to answer.
1. rear wheel is best pressured as to insure best rolling resistance. too high psi or too low increase RR. you should compare looking at the clock for a given wattage and compare psi values by this.
2. front wheel is best pressured as to insure best control of the bike, best grip available dry and wet. RR is very less relevant for the front wheel, control in braking and in turns is much more important when figuring out tire pressure.

so... there are no fixed values because everyone should adapt psi for given actual and possible/probable circumstances.

i'd say i very much like a 50mm rear tire or even a 60 (not yet mounted) with a 40mm front tire. this 50-40 combo is now what i use and somewhere in the future i plan to mount a 60 in the back. a narrow front tire is chosen not for being more aero or anything like that but for better grip when wet and more puncture resistant (a sudden puncture in the front wheel can be very dangerous) because i would not have a wide tire in the front with a low pressure.

so... 88kg bike+rider for this combo (29er) has the same pressure both front and rear: 2.5bar (36 psi).
this combo is useful for an electric bike with a hub motor and a rear rack mounted battery.

why so many started threads in the same day?... 6 total posts... this is very dubious.

anyway, there are many answers you can find to this very question if you search using the search function on this forum...

thanks for your reply most helpful


Simple reason why, is because I cant post images, cant do something else cant remember now until I have made so many posts. I think its 12 posts, just seem to be a silly thing, so hence why i have made so many posts

Depends on the bike and it's tyres. I have a tandem on balloons, heavy rear hub, i'll bet my tyre pressures are a bit different than the next guy's.

There is a range specified on the sidewall. I start with the max pressure on the rear wheel, and then reduce until it is not too harsh/ hard. Even softer on dirt or loose gravel roads. Inflate the front wheel to same minus 10% pressure. (eg. 60 psi rear, 54psi front) THIS IS JUST THE STARTING POINT. Adjust accordingly.

Different tires and different riding conditions dictate adjusting.

> ..I start with the max pressure on the rear wheel, and then reduce until
> it is not too harsh/ hard. Even softer on dirt or loose gravel roads.

Keep in mind when dropping psi that tire pressure is an important factor in the wheel assembly's strength and rigidity.

the maximum pressure is the limit beyond which you can damage the casing of the tire. some tires puncture more easily just because the nylon puncture protection (basic one) has it's plies loosened from plastic deformation when you inflated to tire to a certain point.

the maximum pressure is there so that you will know that for a given weight you should just take a larger tire and do not go beyond that pressure limit.

you should reduce pressure not necessarily by feel but by measuring speed or rolling resistance with the clock. rolling resistance can't be accurately discerned by regular people.
you might find that an even lower pressure is best than what you think is ok now - not being harsh enough is not a good enough assessment.

be sure to lower pressure comparing speed only for the rear wheel pressure adjustment and set the pressure on the front just by feel regarding the whole thing being stable in turns, braking, dry and wet. doing so one wheel at a time means more time but more sure results. also, ensure the tire size so that the right pressure for that size makes it possible to have the least risk of flats.


that's one of the reasons i recommend putting a narrower tire upfront especially if you have it on your hands; changing the rim width is not easily done.
a front tire no larger than needed for proper pressure and also not too much sideway flex for a given rim. rear is no big deal if it has more sideway flex.