Minimum MTB tyre pressures?
Discussion
Morning all,
Does anyone have any thoughts on minimum tyre pressures?
I'm trying to figure out the best pressure for my kids' tyres. My only frame of reference is my own 30psi tubeless setup, but as I probably weigh twice as much as the two of then put together, they'd be pinging off every root and rock at that pressure!
Obviously I could just use trial and error, but I was wondering if there's a minimum pressure I shouldn't drop before regardless of rider weight if I don't want pinch flats or tyres/tubes rolling off the rims?
For reference, they're a girl of 12 and a boy of 10 on 27.5" & 26" tyres respectively, mostly riding the likes of the red trail at Swinley.
Does anyone have any thoughts on minimum tyre pressures?
I'm trying to figure out the best pressure for my kids' tyres. My only frame of reference is my own 30psi tubeless setup, but as I probably weigh twice as much as the two of then put together, they'd be pinging off every root and rock at that pressure!
Obviously I could just use trial and error, but I was wondering if there's a minimum pressure I shouldn't drop before regardless of rider weight if I don't want pinch flats or tyres/tubes rolling off the rims?
For reference, they're a girl of 12 and a boy of 10 on 27.5" & 26" tyres respectively, mostly riding the likes of the red trail at Swinley.
richardxjr said:
^ that. 30psi tubeless is LOADS. Are they really narrow mud tyres or something?
30psi tubeless isn't loads for an adult it's about the minimum unless you are built like an 11 year old. Any less than 30psi tubeless and I'm creasing the casing shredding tyres to pieces in no time and I'm only 72kg. For reference Jared Graves 76kg I think the interview said published his full setup after last years or maybe the years before (anyway whenever he won't the Enduro world championship), tubeless he ran 26psi front and 29psi rear or higher, 30/32 if knarley.Edited by Herman Toothrot on Thursday 26th November 13:54
Herman Toothrot said:
30psi tubeless isn't loads for an adult it's about the minimum unless you are built like an 11 year old. Any less than 30psi tubeless and I'm creasing the casing shredding tyres to pieces in no time and I'm only 72kg. For reference Jared Graves 76kg I think the interview said published his full setup after last years or maybe the years before (anyway whenever he won't the Enduro world championship), tubeless he ran 26psi front and 29psi rear or higher, 30/32 if knarley.
If I go below 30, I can guarantee almost everyone I come across on a ride will tell me I've got a flat! 
15-20 psi should be fine.
I would go as low as you can, which will depend on tube or tubeless.
If tube, then lowest before you start puncturing. Tubeless is pretty much just about limiting rim strikes.
I've run as low as 12 psi on a standard MTB 29er for a Dutch beach race. It didn't roll off the rim or burp any air.
I would go as low as you can, which will depend on tube or tubeless.
If tube, then lowest before you start puncturing. Tubeless is pretty much just about limiting rim strikes.
I've run as low as 12 psi on a standard MTB 29er for a Dutch beach race. It didn't roll off the rim or burp any air.
Herman Toothrot said:
30psi tubeless isn't loads for an adult it's about the minimum unless you are built like an 11 year old.
OP is asking about 11yo's though 
Just checked my 11yo's 24" He's not an Enduro champ, but is built like an 11yo, runs tubes has plenty of grip and they roll well. 16psi.
Good grief!
I don't think I've ever run a MTB tyre below 45psi !!!
On the road, I've chickened out of trying anything below 80psi.
I think I must be doing this wrong. I am using tubes, not tried tubeless (yet), if this makes any difference? I was last on the scales in September this year, and weighed a smidgin under 75kg.
Should I be looking to run lower pressures on any/all of my tyres then? I've always used the top end of the range stated on the tyre casing as a start point, then reduced it incrementally if it wasn't working out for me. But I've never run a tyre at less than the manufacturer's recommended minimum inflation pressure. I'm probably just too much of a "square"
I don't think I've ever run a MTB tyre below 45psi !!!
On the road, I've chickened out of trying anything below 80psi.
I think I must be doing this wrong. I am using tubes, not tried tubeless (yet), if this makes any difference? I was last on the scales in September this year, and weighed a smidgin under 75kg.Should I be looking to run lower pressures on any/all of my tyres then? I've always used the top end of the range stated on the tyre casing as a start point, then reduced it incrementally if it wasn't working out for me. But I've never run a tyre at less than the manufacturer's recommended minimum inflation pressure. I'm probably just too much of a "square"
yellowjack said:
Good grief!
I don't think I've ever run a MTB tyre below 45psi !!!
On the road, I've chickened out of trying anything below 80psi.
I think I must be doing this wrong. I am using tubes, not tried tubeless (yet), if this makes any difference? I was last on the scales in September this year, and weighed a smidgin under 75kg.
Should I be looking to run lower pressures on any/all of my tyres then? I've always used the top end of the range stated on the tyre casing as a start point, then reduced it incrementally if it wasn't working out for me. But I've never run a tyre at less than the manufacturer's recommended minimum inflation pressure. I'm probably just too much of a "square"
Road bikes and mountain bikes are two totally different things. You might want to reduce your tyres pressures a bit on a road bike in the rain to get better grip, but my 23c road tyres are set at 110psi, and my 35c commuter tyres at around 65psi.I don't think I've ever run a MTB tyre below 45psi !!!
On the road, I've chickened out of trying anything below 80psi.
I think I must be doing this wrong. I am using tubes, not tried tubeless (yet), if this makes any difference? I was last on the scales in September this year, and weighed a smidgin under 75kg.Should I be looking to run lower pressures on any/all of my tyres then? I've always used the top end of the range stated on the tyre casing as a start point, then reduced it incrementally if it wasn't working out for me. But I've never run a tyre at less than the manufacturer's recommended minimum inflation pressure. I'm probably just too much of a "square"
Off road though, you want and need your tyres to be able to deform as you go over roots & rocks and the like, as this is what keeps you gripping, rather than bouncing off everything and pinging all over the place.
The difference between tubed and tubeless primarily is that you can run tubeless at lower pressures, as you don't have the risk of pinch punctures, as there is no tube to get pinched. If you let the pressure go too low, you can "burp" (it's a similar noise) air out of the join between tyre and rim, but that's at much lower pressures.
There is a rule of thumb cliché that says mountain bike tyres should feel more like an orange than an apple when you press your thumb into them.
yellowjack said:
Good grief!
I don't think I've ever run a MTB tyre below 45psi !!!
cripes! is you technique for wet roots "Get off and walk" by any chance?? ;-)I don't think I've ever run a MTB tyre below 45psi !!!
I have run dual ply tubeless down to 14psi, but they were very odd feeling down there, usually run probably 22 in the front and 24 in the rear when i need proper grip.
Max_Torque said:
cripes! is you technique for wet roots "Get off and walk" by any chance?? ;-)
I have run dual ply tubeless down to 14psi, but they were very odd feeling down there, usually run probably 22 in the front and 24 in the rear when i need proper grip.
I have run dual ply tubeless down to 14psi, but they were very odd feeling down there, usually run probably 22 in the front and 24 in the rear when i need proper grip.
Not at all. I rode a couple of laps of the Gorrick Summer monkey MTB race on an old road bike running 25c tyres, and only walked one little gully that was soft sand.I don't currently have a MTB that works, but if I did I'd be out about 3 times a week, most often at night, tearing up some of the most popular MTB racing venues in the area, and the odd visit to Swinley. I'm not fast, I'm the first to admit that, but (apart from massively overinflated tyres, it would seem) my technique isn't too bad. There are plenty of slippery exposed roots in Minley Woods to practice on, for instance.
I kind of knew I was running my tyres at higher pressures than many riders, but I just didn't realise quite how low people were prepared to go these days. Now I just need to get my groupset replaced so I can get out and experiment with some lower pressures, but as a long time roadie I fear that lower pressures will have me paranoid about riding on flat tyres. I'll spend more time checking for p**ctures than pedaling if I go below 40psi, I swear...
I run mine at 65psi, and start to notice when they go below about 50psi.
Then again, I only use it for road commuting, so I might not have helped this thread.
(It is fun overtaking people on road bikes though, especially as it hums along nicely, like a small army lorry.)
Nothing further or useful to add.
Then again, I only use it for road commuting, so I might not have helped this thread.
(It is fun overtaking people on road bikes though, especially as it hums along nicely, like a small army lorry.)
Nothing further or useful to add.
12st
29er tubes on trails (Cannock/ local) front on my last outing was 18 psi, rear around 22. Loads of grip, risk pinches and it does crease the tyre walls.
I don't like to run much higher than that on trails.
Has to be upped for Peak District stuff, just wouldn't get through the day without pinches.
29er tubes on trails (Cannock/ local) front on my last outing was 18 psi, rear around 22. Loads of grip, risk pinches and it does crease the tyre walls.
I don't like to run much higher than that on trails.
Has to be upped for Peak District stuff, just wouldn't get through the day without pinches.
yellowjack said:
Not at all. I rode a couple of laps of the Gorrick Summer monkey MTB race on an old road bike running 25c tyres, and only walked one little gully that was soft sand.I don't currently have a MTB that works, but if I did I'd be out about 3 times a week, most often at night, tearing up some of the most popular MTB racing venues in the area, and the odd visit to Swinley. I'm not fast, I'm the first to admit that, but (apart from massively overinflated tyres, it would seem) my technique isn't too bad. There are plenty of slippery exposed roots in Minley Woods to practice on, for instance.
I kind of knew I was running my tyres at higher pressures than many riders, but I just didn't realise quite how low people were prepared to go these days. Now I just need to get my groupset replaced so I can get out and experiment with some lower pressures, but as a long time roadie I fear that lower pressures will have me paranoid about riding on flat tyres. I'll spend more time checking for p**ctures than pedaling if I go below 40psi, I swear...
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