MTB Specific: What Tyre Pressures

[BikeisLife]

1.1 and 1.2! At 70kg? Holy smokes! Surely that pump must be off or you're barely hitting corrugated gravel with your bike.

I'm similar weight and run the same on a 25mm rim with 2.25 tires. Never hit the rim and the tyre guage works perfectly.

[DieselnDust]

1.1 and 1.2! At 70kg? Holy smokes! Surely that pump must be off or you're barely hitting corrugated gravel with your bike.

 

 

Speaking of pumps being off .....

 

After dinging my rear rim at Fedhealth, I checked my pressures again. removed and repaired the front and moved it to the rear and fitted a used Barzo.

Inflated to 1.5bar front and 1.6rear (measured with my topeak tyre presure gauge.. then switched gauges and used my fabric pressure gauge was only 1.1bar front 1.2bar rear!!!! Reason for pinch flatting found!

I then verified the Fabric as being correct at my local Caltex as being correct and the pressure gauge as being off by quite some margin. It i pretty old or the battery is almost flat.

with 1.5 front /1.6 rear the tyre feels very firm but once under way it feels fast with lots of traction, no draggy sounds when cornering until the limit is reached. Bike feels right again.

 

Moral of the story is check your pressure gauges against a different unit from time to time. If you find one of them is drifting then its time to discover which one and replace

[WaynejG]

I have American Classic Wide Lighting rims in 29". Running Specialised Ground Control 2.3 in the front.

The back is a Fast Trak 2.1.

My weight varies between 101 and 105 kg.

What would be good pressures to use. I had a sweet spot that gave good grip but I stupidly started playing with pressures and now the grip is not so good. I even more stupidly cannot remember what the pressures were before I started fiddling.

[DieselnDust]

I have American Classic Wide Lighting rims in 29". Running Specialised Ground Control 2.3 in the front.

The back is a Fast Trak 2.1.

My weight varies between 101 and 105 kg.

What would be good pressures to use. I had a sweet spot that gave good grip but I stupidly started playing with pressures and now the grip is not so good. I even more stupidly cannot remember what the pressures were before I started fiddling.

 

 

you could start at 2.0 bar front and back and work your way down till you find the sweet spot

 

Tyrewiz tells me 1.5 bar front / 1.8 bar rear. It's usually quite good so you should find the sweet spot somewhere around there.

Edited October 27, 2019 by DieselnDust

[Me rida my bicycle]

I have American Classic Wide Lighting rims in 29". Running Specialised Ground Control 2.3 in the front.

The back is a Fast Trak 2.1.

My weight varies between 101 and 105 kg.

What would be good pressures to use. I had a sweet spot that gave good grip but I stupidly started playing with pressures and now the grip is not so good. I even more stupidly cannot remember what the pressures were before I started fiddling.

I am close to your weight. I am currently running 2.4 Ardent front and 2.2 Ikon rear on 30mm ID rims with pressure 20-22 psi (+-1.5bar) front and 22-24 psi (+-1.6bar) rear. I like working with psi it's smaller differences. O and I am on a HT. Schwalbe tyres needs more pressure rear as they are super thin.

[arendoog]

I have American Classic Wide Lighting rims in 29". Running Specialised Ground Control 2.3 in the front.

The back is a Fast Trak 2.1.

My weight varies between 101 and 105 kg.

What would be good pressures to use. I had a sweet spot that gave good grip but I stupidly started playing with pressures and now the grip is not so good. I even more stupidly cannot remember what the pressures were before I started fiddling.

I weigh 100kg and never go over 2 bar .My go-to pressures are 1.6 front and 1.8 rear .With wide rims that is even better for lower pressures 

[Demetri]

I'm 63kg and run 23psi front and 25 rear. Both Ikon 2.35 on 21mm rims. For the more technical trails I run 20psi front and rear. Oh and I'm on a HT

[cadenceblur]

I have American Classic Wide Lighting rims in 29". Running Specialised Ground Control 2.3 in the front.

The back is a Fast Trak 2.1.

My weight varies between 101 and 105 kg.

What would be good pressures to use. I had a sweet spot that gave good grip but I stupidly started playing with pressures and now the grip is not so good. I even more stupidly cannot remember what the pressures were before I started fiddling.

Similar weight also wide rims with inserts and 2.3 tyres front and rear.

I run 1.5 front and 1.9 rear

 

I also use a digital pressure gauge

[cadenceblur]

Speaking of pumps being off .....

 

After dinging my rear rim at Fedhealth, I checked my pressures again. removed and repaired the front and moved it to the rear and fitted a used Barzo.

Inflated to 1.5bar front and 1.6rear (measured with my topeak tyre presure gauge.. then switched gauges and used my fabric pressure gauge was only 1.1bar front 1.2bar rear!!!! Reason for pinch flatting found!

I then verified the Fabric as being correct at my local Caltex as being correct and the pressure gauge as being off by quite some margin. It i pretty old or the battery is almost flat.

with 1.5 front /1.6 rear the tyre feels very firm but once under way it feels fast with lots of traction, no draggy sounds when cornering until the limit is reached. Bike feels right again.

 

Moral of the story is check your pressure gauges against a different unit from time to time. If you find one of them is drifting then its time to discover which one and replace

Mmm concerning. Also have the topeak as well as a schwalbe. The schwalbe reads 10% higher than the topeak...

[WaynejG]

Another thing concerning pressures. At what point do lower pressures start causing resistance? Often I ride to a trail and do lower pressures cause rolling resistance?

[V18]

Another thing concerning pressures. At what point do lower pressures start causing resistance? Often I ride to a trail and do lower pressures cause rolling resistance?

Think lower pressure will cause greater resistance regardless. If we are talking flat smooth tarmac. If we are on slightly bumpy gravel surface it may be beneficial to not ping off things and rather conform slightly and roll. Where that pressure lies is probably we'll above the point that most of us ride. Maintaining grip and sidewall integrity seems to be the common denominators in mtb.

[King_Crispy]

Another thing concerning pressures. At what point do lower pressures start causing resistance? Often I ride to a trail and do lower pressures cause rolling resistance?

Bud, not being rude, but at 105kgs, rolling resistance isn't your enemy.

It'll only make you stronger

 

 

Unless you burp, then it'll make you woes. No-one likes pushing

[WaynejG]

Bud, not being rude, but at 105kgs, rolling resistance isn't your enemy.

It'll only make you stronger

 

 

Unless you burp, then it'll make you woes. No-one likes pushing

Point taken and no, that was not rude. Edited October 27, 2019 by WaynejG

[Straight Line]

Low the tyre pressures can have benefits in the right conditions. But if pressures are too low and terrain changes from soft to harsh, a couple of negatives emerge.

 

1. Increased tyre movement (tread/sidewall squirm) will reduce tyre life

2. Potential damage to tyres and rims in the case of impact on rocks etc is pronounced

3. Increased puncture rates on tread and sidewall areas

 

Find a happy balance at the hardest pressures you're comfortable with and use these as much as possible. May feel strange initially but your riding style will soon adjust to higher pressures. Tyres will last longer, and downtime will be minimised.

[Rockjock]

I weigh 85kg, ride mostly trails like Northern Farms, the Spruit ect. Nothing too technical. Running 1.8 rear and 1.5 front. Was running 1.9 front and rear for a while but found my front wheel washed too easily...since ive reduced pressures grip is much better..

[arendoog]

Speaking of pumps being off .....

 

After dinging my rear rim at Fedhealth, I checked my pressures again. removed and repaired the front and moved it to the rear and fitted a used Barzo.

Inflated to 1.5bar front and 1.6rear (measured with my topeak tyre presure gauge.. then switched gauges and used my fabric pressure gauge was only 1.1bar front 1.2bar rear!!!! Reason for pinch flatting found!

I then verified the Fabric as being correct at my local Caltex as being correct and the pressure gauge as being off by quite some margin. It i pretty old or the battery is almost flat.

with 1.5 front /1.6 rear the tyre feels very firm but once under way it feels fast with lots of traction, no draggy sounds when cornering until the limit is reached. Bike feels right again.

 

Moral of the story is check your pressure gauges against a different unit from time to time. If you find one of them is drifting then its time to discover which one and replace

I rode trailseeker Cullinan today .Plenty sand ,thick and not so thick ,but rideable .Also plenty rocky with marbels sections and gravel and some tar and graspolle .No mud unfortunatelly .TODAY I HAD PERFECT TYRE PRESSURES ! .On the whole 68km route i was thinking this is as good as it gets regarding tyre pressures .I weigh 102kg .I was floating over the sand and banging down the bad rocky descents .I managed to climb a really steep, loose ,marbles section with enough traction .On the gravel and tar it did not feel asif i was kept back by rolling resistance .So when i was home i measured with my 15 year old trusty joe blow floor pump and it measured 22 PSI or 1.5 bar both front and rear .My normal pressures are 1,8 rear and 1.6 front .This morning the tyres felt a little soft ,but i knew the route and just rode like they were .Use it or not .I just thought i will share my humble experience .Note ! I also have a ryder floor pump that measured below 20 psi ,18 psi perhaps ,but i dont trust it,s gauge 

Edited November 9, 2019 by arendoog