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I know lots of people run low pressures ie. mid 20's psi, especially on tubeless but what do heavier guys ie. over 14 stone use?
I'm 15.5 stone and less than 40-45 feels really squirmy. I use mainly 2.2-2.5's.
Weight, psi and tyre size please.
I'm 15/16st and run around 30-35 psi. Never had a pinch flat as yet. I do run 29er tyres though which i find i can run lower than when i rode 26". I have been down into the low 20's when i have not checked them for a while and still had no problems.
depends on the tyre. Some are much more able to take low pressures than others. I hate the squirmy feel of low pressures and like lightweight tyres so run highish pressures - 35 - 40 psi and I only weigh 12.5 stone. However when I put heavy DH tyres I can drop the pressures to below 30 psi
I'm 13.5 stone and I use 65 psi on a 2.75.Personally even for me, I'd say that 40/45 psi is way low, but thats just my preference.
32-35 psi and 14 stone on a hardtail here!
16 and a bit stone 38 psi works for me with Conti Verticals 2.3's
assuming my gauge is accurate....
I do have wide rims though 729's as when I used to have 717 rims I always got snakebite pinch flats on my hardtail, on the rear, when I was ragging it down Innerleithen.
When I went ghetto for a bit, I was at 30psi
15st or s; Conti UST, Spesh 2Bliss and Geax TNT tubeless tyres all 2.2" - about 32psi at the back and 28 at the front.
14 stone
15 psi
100 kg
I don't have a pressure gauge but i seem to be able to go quite low on the pressure front, with the only issue being drag if you go to low.....
15.5st and rarely over 35psi apart from skinny mud tyres, and even then it's only 38-ish. I do go as low as 26psi on some tyres without a problem (Bonty Jones ACX)
I'm 13.5 stone and I use 65 psi on a 2.75.Personally even for me, I'd say that 40/45 psi is way low, but thats just my preference.
What tyres/rims are you using?
65psi has got to be way outside the spec of a lot of them
Does depend a lot of the tyre, especially sidewall thickness. I'm the wrong side of 15st as well and generally run 35psi on normal tyres (but running them tubeless), if I got proper tubeless tyres I'd probably experiment down to about 25psi
14 stone and 30 to 35psi if i remember to pump it up before a ride but ridden as low as 20psi before
14stone. 28-30psi on 2.1-2.3's. Any lower and things get a bit squirmy and the rocks start meeting my rims. Recently I've rolled a tyre off the front a couple of times(a function of tyre bead fit and pressure).
As has been said, the thicker the sidewall, the lower the pressures. I use to run 15psi when I ran Tioga fat66 DH tyres. I reckon I was held up as much by the sidewalls as I was the air pressure!
You can't try those sorts of things with bonty TLR's though. They just fold over like Cav's wheel did recently.
15.5 stone here and running 30psi in 29er racing ralphs on a hardtail.
I think I could run a bit less, but it seems to work OK for now
16 +/- 1/2 stone and 40-60psi depending on tyre and weather
15st running ron and ralph with slime tubes at the mo, not that makes much difference ime at 30f 35r allthough i'm not that confident in my gauge...
16st 40psi nobby nics 2.25
13.5 stone & something around 40psi for 2.1 & 1.9 tubed xc tyres, don't really get the how low can you go thing at all
17 stone or 110kg, typically running 2.35 High Rollers tubeless with Stans at around 30-35psi for Surrey Hills riding. In the Peak/Wales I have to run a dual ply rear at about the same pressure otherwise I pinch/rip the tyre to bits.
I'm about 17st, running a rear High Roller XC (2.1, too narrow really) and front Nevegal 2.1. Both are about 50psi at the minute. I might lower them a bit as recently I tried the rear one a bit lower (I'd guess around 35-40) and I could feel a lot more grip, although also felt a bit "squirmy" round tighter corners. I also bottomed out onto the rim on a few landings, but didn't pinch. Should have checked what presure I was running really so I could try something slightly higher! 50 is my usual though.
Tom you should running a slightly bigger tyre, say a 2.35 High Roller with less air pressure; depending on where you ride say around 35psi. 50 psi is seriously high and the difference that running a higher volume lower pressure tyre will make will be huge. It will probably feel like going from a hard tail to say a 100mm FS bike.
16.5 stone and run 40 in normal tyres like verts, 50 in skinny tyres like Bonty mud x and 85 in my 35mm cx tyres
I can usually get away with about 5psi less but risk pinches then so don't.
100kg
29x2.0 or 29x2.1 ghetto tubeless on a hardtail.
50psi
Even on my old 26er FS I was constantly burping tyres at anything less than 40psi. Maybe I just never found the right combination of rim and tyre.
I've ridden a lot of marathons and chased, or been chased by, thousands of riders over all sorts of surfaces.
I've never felt myself to be at a disadvantage because of my high tyre pressures.
Lower tyre pressures giving better grip is just a myth.
Its a long story...
I'm 16 stone.
Normally single ply highrollers 2.35 on trail bike. Usually run these at around 35-38 psi. Still get the occasional pinch flat but bike feels skittish with tyre pressures much greater than this. Run a bit harder if its a longer distance route with more fast fireroads etc. If I'm running 2.1 mud tyres or the like then I'm up around 40 psi.
On the DH bike I run 2.5 dual ply highrollers usually. Normally run about 25 psi on the front and 25-28 psi on the back except at Fort William where I need 35 psi to avoid pinch flatting on every run...
depends entirely on the volume of the tyre
I'm 15 1/2 stone and run 2.4 rubber queens at around 20-25psi but 2.3 conti verticals at 35-40 psi.
Lower tyre pressures giving better grip is just a myth.
No it isn't. You may not have felt the benefit and made your choices accordingly, but thats not to say they don't give more grip.
16st.
2.1 Panny Fires
35psi 'ish both ends - used to be more like 40-45 but, having recently dashed out on a ride without usual cursory checks I noticed the bike rode far better... I did notice the softer back end during the ride, feeling the tire 'give' on small rocks etc but it did not feel any more draggy....
Got home and checked the TP's with the track pump and thought 'right, that's the pressure for me then.'
I will not say that I have not had a pinch flat issue because that will jinx me 🙂
100kg here. 25 front 31 rear on 2.5 dual ply minions. Single ply tends to roll over a bit at t
he lower pressures
Ditto scienceofficer. It's a well known and easily explainable one too.
how about us with light bones ?
60kg and 40psi
...although I must admit it's a bit skitty in places in this dry weather. Could do with letting 5psi out the front.
Kev
Ditto scienceofficer. It's a well known and easily explainable one too.
Exactly. It's so obvious I wonder if the comment was a deliberate Troll.
OK, you're right.
I must have overtaken well over 100 other riders at Bristol Bike Fest as they all stopped to mend punctures, while I noticed no difference in cornering speed or braking distance.
You all keep running at low pressures. Suits me 😉
I'm with MiltantGraham!
Stupid low tyre pressures = emperor's new clothes
15 stone, 40-45 psi
If you're not getting decent grip, get better tyres
I've never bothered guessing what PSI I have in my tyres, as it's probably inaccurate, but:
As I ride a hardtail, and am 15st (on a good day) I like my tyres soft enough so they don't bounce me about over roots etc but hard enough not to flop about in corners.
I tried a 2.1 High Roller and couldn't find the happy medium, A 2.3 Conti Vert UST (same) but now I've got a 2.35 Bonty XR4 tubeless and I can get it "just right", just like the Big Earl I used to have on there.
"Just right" is bloody hard less 2 pssssts, if you need a more scientific explanation.
Last Thursday night I tried it with 3 pssssts and I had to stop and pump it up a bit more.
18st 😯
2.1 Nobby Nics
45psi
I must have overtaken well over 100 other riders at Bristol Bike Fest as they all stopped to mend punctures
Sure but unless you came first there must have been some people running lower pressures and getting better grip as a result. It's all about compromise; run 30psi on a single ply tyre on a rocky course and suffer endless pinch flats, or run a dual ply tyre and get more grip but more weight, or run lighter tyres but with higher pressure and less grip. As has been said, you've found the compromise that works for you but don't kid yourself that it doesn't make any difference because it clearly does.
I agree that there is a point below which the tyre pressure becomes as much of a hinderance to grip and progress as running too high a pressure. For the average rider on an average single ply tyre that pressure is probably somewhere below 25-30psi but that's a very broad generalisation.
'I passed other people with punctures so low pressures don't give more grip'
How very scientific and objective.
Have you considered the other multitudinous (almost too many to mention) variables may be a factor in this rather than linking random data points?
Your logic is the same as drowning women to prove they weren't witches.
It may suit you, and that's fine, but your justification is no kind of justification at all really.
14 stone on super tacky 2.35 High Rollers. about 37psi
Anything less than that and it's like cycling through treacle
Scienceofficer, I think you're confusing my two arguments.
1. Higher pressures reduce the likelihood of pinch flats. I think we're all agreed on that one.
2. [i]I have found[/i] higher pressures do not reduce grip.
If I found that higher pressures reduced grip, I would look for a compromise between losing time riding slower round corners and losing time mending punctures.
I haven't found that, so why compromise. Pump 'em up, avoid punctures, roll easier and go round corners the same.
[i]"How very scientific and objective."[/i]
I think this is the key point.
Like most things in mountain biking, it's all marketing, personal preference and repeated folklore.
Has any scientific and objective testing ever been published on MTB tyre pressures ?
16.5-17 stone and around 25 PSI tubeless on 2.5/2.3s
6'3 and 17 stone and role on some fat Nobby Nic's (2.4) or Racing Ralphs (2.35) at between 35-45 PSI dependant on the trail conditions.
If I found that higher pressures reduced grip, I would look for a compromise between losing time riding slower round corners and losing time mending punctures.
You know it is possible for this to be true; it's basically about cornering speed. I think what people are saying (including me) is that tyre pressure affects the contact patch, which will 'change' the level of grip and therefore be a factor in determining cornering speed.
There are a number of factors, like weight distribution, balancing the bike font and rear, use of the brakes, suspension performance, that determine how fast you're going to be able to go around a corner; the contact patch on the ground is only one of them. If these other factors are far from optimal, then they will be the limiting factor long before tyre pressue is hence why you might not see any benefit from lowering that pressure.
Has any scientific and objective testing ever been published on MTB tyre pressures ?
I believe Schwalbe has done some work on this.