Michelin pro four Endurance v2 - Max PSI 87?!

[RideToWorky]

hi All,

Michelin pro four insurance v2 - Max PSI 87?!

I've managed to fit the front new tire. It started raining, so had to pack things away. Will finish the rest tomorrow

I noticed something though, packing up. On the tire sidewall, it says the maximum psi is 87?!

Road bike tires, pumped up hard, would go easily to 110 psi?!

I pumped the tire up hard, like usual. That feels fine.

Any advice on this?
This is a weird thing that Michelin does to cover themselves?!

Cheers Martin

[TrevA]

According to Bicycle Rolling Resistance, the max pressure is 109 psi

http://www.bicyclerollingresistance.com ... ce-v2-2015

[Samuel D]

BRR tested the nominally 25 mm version (though it measured 28 mm on a fairly wide rim). I guess RideToWorky has the 28 mm version.

Michelin may be more cautious than some other tyre companies, preferring the user to have a greater safety margin for heavy braking on descents (which heats the rim and therefore increases pressure).

Or perhaps Michelin’s sidewalls, which tend to be quite supple in my experience, are simply weaker than average.

At any rate, you’d have to be a big boy or girl to need more than 87 PSI in a 28 mm tyre.

[NATURAL ANKLING]

Hi,
World Tours are stated at 87 psi max 700 x 35.

[Samuel D]

The odd-sounding numbers – 87 in this case – come from (needlessly precise?) conversions from the original units of bar. 87 PSI is 6 bar.

Most Michelin road tyres have lower maximum pressures than equivalent tyres from competitors. If you’re on the heavier side of average, this may be a problem.

As a lighter rider, I would actually like tyre manufacturers to offer two versions of their tyres, one with a weaker, more supple casing with a lower maximum pressure. Of course I understand why companies don’t do this (but maybe there would be room for one of them to do so?).

[Brucey]

...At any rate, you’d have to be a big boy or girl to need more than 87 PSI in a 28 mm tyre....

Indeed; if you stick to the 15% drop idea, ~87psi in a 28mm tyre would be right for a ~54kg wheel load, or (with, say, a 45-55% weight split) a ~98kg rider + bike.

This presumably reflects the intended use of this lightweight tyre; i.e. for training/racing. Those who are intending to carry a heavier load would usually be better off with a wider, tougher tyre than that.

cheers

[RideToWorky]

Hi all,

Many thanks for the advice!

I have a foot pump, and it's pretty imprecise, a lot of the air goes out of the tires when I take the adaptor off.

For the old 25MM tires, I would just pop them up as hard as I can, and I did that to self, and just check they are hard

Can I do this for the 28mm tyres? It would I be overpumpinh them for a light 8st 11lb rider?!

Haven't had chance to take take out for a ride yet!

Regards
Martin

[Samuel D]

I have a foot pump, and it's pretty imprecise, a lot of the air goes out of the tires when I take the adaptor off.

It may make a loud noise when you remove the head, but I doubt a lot of air is leaking from the tyre – more likely it’s the air in the hose expanding rather rapidly as it falls to atmospheric pressure.

Guessing tyre pressure by thumb can be done very roughly if you have plenty of experience with that particular tyre and a reliable pressure gauge. Otherwise it’s wild guesswork.

I’d buy a proper pressure gauge or possibly a pump with one attached (since foot pumps aren’t usually very suitable for high-pressure clinchers).

[pwa]

Hi all,

Many thanks for the advice!

I have a foot pump, and it's pretty imprecise, a lot of the air goes out of the tires when I take the adaptor off.

For the old 25MM tires, I would just pop them up as hard as I can, and I did that to self, and just check they are hard

Can I do this for the 28mm tyres? It would I be overpumpinh them for a light 8st 11lb rider?!

Haven't had chance to take take out for a ride yet!

Regards
Martin

I weigh something like 14 stone and pump Conti Grand Prix 25mm tyres up to about 90psi on the rear, a bit less on the front. Much harder than that and the tyres lose their suppleness and speed over coarse road surfaces drops, as does comfort. With air pressure, optimum and maximum are not the same thing. Try the 87psi and see how it feels.