Tyre pressure. How things have changed.

tasty.dirt74

Likes Bikes and Dirt
So reminiscing tonight about tyres and how they have evolved over the last 10-15 years.( should this be in vets thread?)

Every Sunday there would be a ride with locals , but mostly customers of a lbs I was friends with the mechanic of. Almost without fail, there were a number of stops initiated by someone getting a flat. 10 mins here and there added a hour sometimes to the ride time..

So as a result , trying to prevent punctures resulted in ridiculous psi being run. 34 and you were risking a flat sometimes.. 40 was not unheard of..

So then came this tubeless business... I was lucky enough to get a bike which had crossmax wheelset back in about 06(?). The first time I tried to take a tyre off resulted in much sweating.. lucky I used to b a tyrefitter by trade so has a bit of a advantage.. but I understand what seating beads and the ust concept was all about..

This all brings me to today. Yesterday actually as I am slow to write this sort of stuff down..

The tyre pressure I was on today was 12 front and 16 rear.

Now this is not a plus bike or a fatbike.. run of the mill 29er if you please.

30 mm internal rims. No special anti-puncture preventatives installed. Tyres are Bontrager 2.2 Xr1 rear and massive minion dhf 2.5WT. FYI..

This pressure was almost by accident as it was the tyre press test to verify pressure was used.. now honestly it was too low, but whilst the terrain was wet, I could see definite advantages to this LOW pressures being useful . Now to look at one of those tyre inserts for rim and flat damage prevention I guess ?








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schred

Likes Bikes and Dirt
Was riding with a mate new to MTB, I convinced him to lower the pressure to 35 from wherever it was, 50 or so, then he pinch flatted. I barely knew what to do it had been so long since I've had one.

What do you use for a gauge? Presume you've got a version of the "truth"?
 

Andrew Fist

Cannon Fodder
Similar experience for me. I raced road & track as a teenager (long time ago) and 120 psi in singles was the norm.
Got into MTB a few years ago and ran 25, 23 psi in tubeless 29er 23mm internal.
Now I run 12 psi front and 15 psi rear in 2.8 DHF / DHRII on 45mm internal rims and will never, ever go back (unless I am sucked into an occasional 70k XC epic). Safe, comfortable, fast. Tremendous grip means you can maintain speed when cornering and so overall ride performance is much improved. And did I mention the safety & comfort?
So I'm not a young DH racer, would probably opt for 2.5 or 2.6 and a few more psi if I was. But for this punter low pressures are here to stay!
 

ChrisJC

Likes Bikes and Dirt
I recently purchased a Schwalbe digital tyre pressure gauge, reads pressure a bit lower than the gauge on my pump.
floor pumps seem to be very inaccurate at lower pressures. I have 2 floor pumps, a cheapie and a Joe Blow. Both read about 4psi lower than my digital gauge.
 

stirk

Wheel size expert
Man that's low pressures! Bet your tyres were squirming around on hard cornering.
Nah, my guess is the guage is reading low, 12psi even for my light 72kg nude self is impossible, at least on actual mountain bike trails.
 

tasty.dirt74

Likes Bikes and Dirt
Was riding with a mate new to MTB, I convinced him to lower the pressure to 35 from wherever it was, 50 or so, then he pinch flatted. I barely knew what to do it had been so long since I've had one.

What do you use for a gauge? Presume you've got a version of the "truth"?
I normally use a digital pressure gauge, and the track pump has one also.. Although the pinch and squeeze method is fairly well calibrated, or so i thought!

This low pressure instance was brought about by the new front tyre. Soo wide !! And hard to judge pressure apparently !
 

BT180

Max Pfaff
Nah, my guess is the guage is reading low, 12psi even for my light 72kg nude self is impossible, at least on actual mountain bike trails.
Makes sense. I just bought one of those Topeak Smart gauges and it's been a real eye opener.
 

link1896

Wheel size expert
Times have changed, but so have tyres.

In the old days with 1.75" tyres, 50-60 psi was common. Combined with undamped elastomer suspension, no idea how we did what we did
 

safreek

Vealcake
Times have changed, but so have tyres.

In the old days with 1.75" tyres, 50-60 psi was common. Combined with undamped elastomer suspension, no idea how we did what we did
Because we were hard bastards, with real wheel sizes.
Next thing you know there are namby pampy wheel sizes that make getting over obstacles easier.
But then again, sardine tins made good shoes back in them days, not them oversize haddock tins that made your feet feel good.
 

flamin'trek

Likes Bikes and Dirt
Times have changed, but so have tyres.

In the old days with 1.75" tyres, 50-60 psi was common. Combined with undamped elastomer suspension, no idea how we did what we did
It was largely fire-trail stuff and a lot slower because of less traction.

I remember comfortably riding the DH track at Ourimbah in the late 90s on an XC bike, but it was no harder than current XC blue trails. One of the fastest guys was on a hardtail, then the trails started getting all gnarly. It was when you started to need a dually - because the guys with duallies were building tougher obstacles into the trail.
 
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