To The Point - Tire Pressure

Jun 11, 2013 at 0:07
Jun 11, 2013
by Mike Levy  
 
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Although Geax's Ken Avery may not be a name that many will recognize, he is the man responsible for the design of one of the most successful downhill tires of all-time. Now the brand manager for Geax, Avery is in control of the Italian brand's product design and development, from basic concept, prototyping, and through to production. Given his background of understanding tread layout, compounds, and casing designs, as well as a history of racing at a relatively high level himself, Avery has an intimate knowledge of how air pressure effects tire performance.




There is always a lot of talk about tread pattern and rubber compounds, but where does air pressure fit into the picture?

Air pressure is the one thing that is easy for any rider to tune on their bike. Air pressure
allows the rider to get the most from their tire selection. In other words, if they chose
a fast rolling XC tire, the proper air pressure will allow the tire to do its job and roll as
fast as possible. If the rider chose an aggressive DH tire, and wants ultimate grip,
letting a bit of air out will allow the tire to conform to the ground better, deflect less, and
ultimately grip better.

When a tire is designed, the tread pattern is formulated around the intended use, casing,
and compound, as benchmarks for how the tire will flex (and ultimately perform) under load.
Tuning the air pressure allows the tire to deform the optimal amount that it was designed
around, for the rider’s unique criteria: rider weight, use, terrain, and riding style. Air pressure
is essentially the link between the tire’s design and the rider.

Geax Goma

The optimal air pressure allows the tire to conform to the ground better, thereby improving traction. Too much air and the tire will tend to bounce off of objects, lowering traction.



If running more air pressure makes for a harder and faster rolling tire, why don't we all run higher pressures?

More isn’t always better. Often, speed comes at the price of control. First off, the more air
you put into the tire, the more rigid the structure becomes. Also, air acts as a spring
inside your tire, and there is very little to dampen the feel of rebound at higher pressures.
An overinflated tire will tend to bounce off objects in the trail (deflection) and also not
conform to the ground (deformation) as much. This reduces the footprint of the tread in
contact with the ground, which reduces grip. The reduced grip will increase understeer, increase
braking distance, and can even increase rider fatigue. Even a road tire at 125PSI is designed
to flex a certain amount in order to increase performance.



What could a rider expect to feel if their tire pressure was set too low?

Again, more isn’t always better. So often riders get the idea in their head that they will have
better grip by decreasing their pressure to an irrational point. Remember, it’s the air pressure
that is keeping the beads in your rim (with the exception of tubular tires, which are glued on). You
will know when you reduce your pressure too much when you can feel your rim bottom out on
the ground as you ride over small obstacles, and if you “burp” air out of the bead when running
tubeless. The impact of your rim on the ground can cause rim damage, and can also (and likely does)
pinch the inner tube, causing a flat tire. Lastly, running too low of pressure can cause poor handling ,
especially on the front wheel, and increased rolling resistance. Despite the efforts to go faster, you
can actually go slower as a result.


n a

Adjusting your bike's tire pressure to suit the day's ride will allow you to get the most from your tires for the given terrain.



Do rim widths and different types of tire casings factor in when determining the ideal air pressure to use?

Absolutely. The rim width will affect the tire’s profile. A wider rim will make the tire appear more
square, and a more narrow rim will make the tire feel more rounded. This will affect how the
tire deforms under load. A more square tire will allow the side knobs to start doing work sooner
than a more rounded tire, so the knobs won’t be as likely to get overwhelmed under hard
cornering. A rider with narrow rims can tune this a bit by lowering their air pressure to allow the
rounder profile of a narrow rimmed tire to deform more and provide increased traction. This is only
true to a point however, and will likely be less stable at speed than a tire on a slightly wider rim.

The casing controls how the tire tread deforms, how impact-resistant the tire is, and (especially at
lower pressures
) contributes to how the much control the rider has. A thinner or higher TPI casing
will allow the tire to deform more, thus increasing comfort and grip. They also weigh less than thicker
casings. However, in high impact applications like DH a thin casing can get overwhelmed and become
less stable due to the force of impacts. A thinner casing also allows the tire to “flop” from side to
side more than that of a thicker casing. For these reasons, DH tires are 2-ply, for impact resistance,
stability, and control, but are still used at a low PSI to increase grip.



Does a faster or more aggressive rider require higher air pressure than the average rider? Why is this the case?

If it were as simple as adding air to fend off impacts, all tires would be made the same. As a kid
growing up racing DH in the early 1990s, XC tires were all we had, and it was brutal. The
development of tire technology is one of the best performance advancements in the bicycle industry
yet. A World Cup downhiller pushes their bike to a level that no other rider does. The harder impacts,
speed, and required control demand that the tire be stable, and still grip better than anything else. Also,
at the end of the day a World Cup guy is a racer, so rolling resistance still comes into play.

Solely based on these points, it would seem that a World Cup racer would need a higher PSI. However,
as a famous car company once said, “speed is nothing without control”. The tire still needs to deform
to the ground to provide grip. For this reason, the pressures that you see on the World Cup circuit are
fairly normal. As I mentioned earlier, it’s the tire construction that is different on a DH tire, which allows
the speed AND performance that the World Cup guys demand.

Cam Zink s drop into his Canyon Gap run in is alsmost as hairy as the canyon gap itself.

A rider like Cam Zink, shown here at the Red Bull Rampage, asks far more from his tires than the average rider.



Has the shift to tubeless setups changed the way we should be calculating our tire pressure?

The point of running tubeless is to be able to run lower pressures without pinching a tube, and to gain
traction and suppleness. It also saves weight, which is a perk. Because there are so many different casings,
and company standards, each company’s tires will have a different feel when run tubeless. At Geax, we have
a TNT bead, which can be run Tube/No-Tube. Because the tire was designed to be tubeless compatible, a
rider can use a more broad range of usable pressures without burping at the bead.

When you take away a tube, you take away material. This material runs parallel with the casing, and can
provide a certain amount of stability and dampening for the tire. For this reason, when you take it away,
the tire can feel lighter and more grippy. Remember though, air is what holds the tire in place, so when a
tubeless tire burps, you can lose air in a hurry, and can also lose stability. On my personal bike, I don’t run
drastically less than I did when I ran tubes, but as with everything MTB, it most often comes down to what
the rider prefers.


www.geax.com
Must Read This Week









188 Comments

  • + 261
 All this pressure is making me tired.... Ba Dum CHAAA!!
  • + 227
 Really? I'm totally pumped!
  • + 339
 I'm just annoyed with how much tires have gone up in price over the last few years, I blame inflation.
  • - 127
 It's our fault not inflation Wink
  • + 77
 Inflation is better than deflation in this case though
  • + 176
 You have to tread carefully with all these puns around!
  • + 174
 What a gripping article!
  • + 29
 i love this thread
  • + 29
 thanks you all of you, you have just made my day, i have never laughed so hard at so may brutal puns. truly brilliant. the article was good, i am glad that the pinkbike is putting out some good info.
  • + 125
 You guys are all just being knobs.
  • + 94
 Tu-be honest, this is a thorny issue, but I like how they roll with it without too much hot air.
  • + 33
 jivehoneyjive that was painful haha
  • + 54
 you know I love stans, it really seals the deal
  • + 85
 This comment section is going round and round in circles,or maybe i spoke too soon? I guess it's just how you guys roll
  • + 7
  (end italics!)
  • + 81
 50psi in my minions, I don't care about your opinions
  • + 81
 All these puns are starting to get a bit flat
  • + 55
 I feel pressured trying to come up with a good comment to get it rolling again
  • + 24
 I can't help thinking that this tread has become over-inflated with puns.
  • + 20
 Loving all these puns and feel the need to contribute, I just hope I don't i>blowi> it.
  • + 26
 and he blew it on the italics ... Wait...

His italics had no traction (much better)
  • + 12
 The OP has spawned many minions, I guess he´s a PB high roller.
  • + 7
 I loved the article. I guess it stems from the fact that we don't know much about pressure.
  • - 29
 to bless my bike before I ride is what works for me
  • + 6
 Get a grip guys , this article was great really gripping ! (btw whats with the italics , gonna make me burst !!! )
  • + 5
 Too much pressure on replying with a good pun i think i might explode :/
  • + 22
 Tu-be or not tu-be. Stans is the question.
  • + 5
 The hub of the matter is, there's too many puns spinning around -Ok we should probably stop now xD
  • - 3
 Don't stop, keep rollin' rollin' rollin' rollin' Razz

The italics worked for me originally, don't know what happened.
  • - 2
 Feels like I'm treading water over here in this comment section
  • + 2
 end italics

You can use the text formatting tags from the forum to format your comments into bold or italic text... I think hyperlinks work as well... Only problem is there's a small bug in PB's code that doesn't automatically close any tags you leave open

So all it takes is a [ i ] without and [ /i ] to italic the rest of the page... So tempted to put a [ B ] right now!
  • + 5
 I tried to get my bicycle to stand up. But it was two tired.
  • + 4
 this article is wheelie good
  • + 4
 Oh No... Someone let the air out of this thread....
  • + 1
 well let's pump it up and put it back on track..
[Reply]
  • + 29
 110 psi in my conti grand prix..... ahhhh wrong thread?
  • + 6
 16 psi in my cyclocross tubs.... wrong thread aswell..
  • + 6
 ...5 psi in my big fat larry 4.7's... probably not gonna go down well either...
  • + 22
 7psi in my basketball.........shit wrong site and wrong thread.
  • + 2
 85a durometer for my inline skate wheels.......huhuhuhuh.
  • + 31
 I don't think I would ever admit to owning inline skates.
[Reply]
  • + 18
 I think I saw it in Dirt mag or website: a thesis about rolling resistance from somebody in a german university. Shrunk down to a couple of lines, it says higher pressure reduces rolling resistance on flat grounds, but not on "chunky" terrain where tyre deformation in that very case reduces rolling resistance. Of course as always within certain bounderies... at 1 bar (sorry, dunno anything about psi) you'll have massive rolling resistance I guess!
  • + 8
 Yeah I read the same thing , makes perfect sense really. High pressures only increase rolling speed if the ground is near perfectly smooth basically due to it's deflection.
  • + 5
 If the tyre flexes around a bump, the weight of the bike continues to move, give or take, in the direction it was before the tyre hits the bump on the ground... However at a high pressure, the tyre is deflected upwards over the bump - lifting the mass of the wheel, suspension linkage or fork and potentially the weight of the bike and the rider! All this energy to lift the mass of the bike has to come from somewhere! Over a small bump, this will make very little difference, however over a distance, this will significantly decrease the speed of the bike, like riding over 100's of tiny uphills!
  • + 0
 Actually as far as flat ground goes... that's perfectly smooth rollers in a lab.... on actual asphalt roads.. less pressure / wider tires is now the IN thing. Where it used to be normal to see riders on 21-23mm width tires in big road race events, now they're on 25-27mm width tires running 10psi less pressure and the speeds have increased.
  • + 1
 sweet.. confirms my 2.4" tire choice at 28psi for this weekends Test of Metal then Smile
  • + 6
 You might take a look at the diagram below ...
www.mountainbike-magazin.de/sixcms/media.php/6/MB_0305_Speed_Diagramm_3.jpg

For the non-German-speaking people:
x-axis = tire pressure / bar
y-axis = rolling resistance / watt
Green = meadow; red = gravel; black = street.

On loose/soft ground -> the higher the tire pressure, the bigger the rolling resistance.
Only on hardpack/street higher tire pressure means lower rolling resistance.
  • + 1
 Thanks redVellocet! Good to see some actual data.
  • + 0
 That study was performed at 9km/h where rolling resistance due to material damping is negligible. It does not apply at higher speeds, and is quoted by many people to support the erroneous notion that fat tyres at low pressure roll faster all the time.
  • - 1
 @deeeight, you have to be careful with these generalizations. The pros switch up tires depending on bikes, courses, wheel choice, ... and are not solely going to wider tires. We've seen quite a few articles on this topic lately because of the Spring Classics that are run on rough roads and flatter courses than we see in the grand tours. The wider tires really shine on these Classics courses because they are more comfortable and roll much better on the cobbles.

When it comes to courses on smoother roads, higher speeds, time trials and climbs you'll find that narrower tires like 21 and 23 still rule the pro world even on wider rims. The lighter weight and better aerodynamics of the narrower tires trumps the slight increase in rolling resistance.
  • + 1
 Ah and there's the other new trend coming over to road from mountain bikes, although really it goes back to the automobile world... wider rims to support existing tire widths better, effectively low-aspect ratio tires as sports cars use.
  • + 2
 @deelight. Ever notice that F1 cars don't have low aspect ratio tires? Same with rally cars. Those low aspect ratio tires are to make a car feel faster(and maybe look faster), not to make it actually faster. Width of rim must be suitable to width of tire chosen.
  • - 3
 @deelight, wider rims do not lower the aspect ratio of tires any significant amount, if at all. The tires get wider and taller.

@foghorn1 is correct, you need a decent amount of sidewall height to allow the tire to track the ground properly. Besides, bike tires are essentially round while car tires are not at all so they are very tough to compare.
  • + 2
 I'm sorry kids but that's wrong... bicycle tires don't magically grow in two dimensions just by changing the rim width. Wider rims flatten the tire profile out and cut the height of the casing, narrower rims do the opposite. You really outta measure tires yourself with calipers over different rims, and not just rely on something you read in MBA.
  • + 1
 I've tested a ton of tires in the past couple of years and have measured most of them on different rims. I stand by my previous statement and my findings agree with Shiggy's for the most part.

mtbtires.com/site2/tech/38-general/96-29er-tires-on-different-rim-width-comparison

@Deelight, try to remember back to the 4 times you took Mathematics 9 and think about how the geometry changes when you add circumference to a circle (the tire casing in this instance). You talk about flattening the tread which is a different way of saying that the tire's casing circumference grew.
  • + 1
 Yes well I've found shiggy didn't even know that Schwalbe tires stretch significantly between when you first install and inflate them, and an even just an hour later. The RaRa 29 x 2.4 for example will stretch 6 or 7mm in width between first inflation and coming back to the bike later, and that's on a 24mm width rim. So I don't particularly trust a lot of his numbers anymore.
[Reply]
  • + 15
 On my 2.4 rubber queens (the-rest-of-the-world name for conti trail kings (US only name)) it says recpmmended 35 - 50 psi, I know noone running over 30 psi in these. This is true for a lot of ture producers. Why recommend a pressure noone uses?
  • - 18
 Becouse 35 would be a starting point 50 would be your max point really . If it didnt say 50 on them users would go over that and find them selves covered in tubeless liquid . Trust me going over the 50 psi on a tire that says 50 shits you right up when it blows off the rim lol.never again lol
  • + 13
 "SuperBikes" please read "Ynotgorilla's" question again. I think you didn't understand what he was asking.
  • + 1
 Running low 20's in my 2.4 RQ/TK's. Conti defiantly sold me on those, such great front tires.
  • + 15
 wonder why they are called trail kings in the US, has hyper political correctness struck again?
  • + 5
 I've always been perplexed by that 'recommendation' and simply ignored it. 2.4 front at 23-25, 2.3 rear at 28-30, inflate to 50 for tubeless seating.
  • + 9
 I think it't a liability thing. At least 35 to ensure the bead is seated and the tire won't blow off the wheel, and 50 max so you don't over-inflate and blow your face off. Really if you are running under 30psi you should at least be initially inflating to that to seat the bead.
  • + 4
 the inflation number on most tires are not a guide to which pressures to run but a range in which the tire will seat to the rim properly. It's amazing how many people dont seat the tires properly , when you look at their wheel spin you can see the ' wobble ' where its not seated correcty resulting in an inconsistent tire patch
  • + 2
 35 for tubeless is too much... below that is A good starting point
  • + 3
 Stans no tubes recommend less than 40psi for tubeless conversion setups... Usually I got up to 40 and then reduce the pressure appropriately, to ensure it has seated properly before setting my pressures (also helps make sure it has sealed correctly as well)

I agree with DARKSTAR63, I imagine the minimum recommended low pressures are to ensure the tires don't blow off the rim too easily (presumably as a result of some lab tests or something equally exciting)
  • + 1
 Good point
[Reply]
  • + 14
 A range of psi for different tires and applications would be helpful.
  • + 25
 In my opinion, 30psi in your minions...
  • + 1
 I run about 30psi in my minions and i'm about 87kg. Awesome gripping tire in 2.5 supertacky. But of course too heavy for really good fun all mountain.
  • + 25
 30psi in my minions, i don't care about you opinions
  • - 2
 30 is quite high unless you are riding very very rocky tracks , or tarmac.
  • + 5
 Wouldn't rider weight be a rather important factor to include.. Would be a rather large chart!
  • + 3
 if youre running less than 30 and its not causing a problem youre going too slow
  • + 4
 The same could be said if you are running above 30 due to lack of traction. Spose it depends on your weight and other things
  • + 1
 And conditions. I run lower in the wet.
  • + 2
 20psi in 2.5 muddy marys dual ply on my big rig. Im 9.5 stone though...
  • + 2
 Courtesy of a unnamed world cup mechanic and a few contacts, I have a spreadsheet for calculating optimum tyre pressures

DH - 28 psi front / 35 psi rear (dual ply HRIIs)
  • + 1
 Around 26 PSI in my Minion 2.5 EXO's, tubeless.
  • + 9
 oh my god none of you f*cking get it. theyre referencing "I'm faster than you," @Allergysix and @Spearman are not actually talking about their tire pressure. no one really gives a f*ck what pressure you guys are actually running.
  • + 1
 I've heard most of the lighter World Cup guys run a little less than 20 in the front, and not much more than 20 in the rear.
  • - 3
 That was at Port Angeles, pretty soft dirt.
  • + 3
 28 front 30 psi rear in my dual ply minion 2.5 DHF's. Running XC tubes and haven't had a flat in 2 years. Less pressure feels a little better, but I hate wearing a pack and I despise flat tires. Why are all of the comments in italics?
  • + 1
 I normally run 35 - 40 psi in my Highrollers on my hardtail and ride it on everything!
  • + 1
 im 65kg i run between 20-25psi front and rear. minion 40a front highrolla 3c rear. rolls slow as on flat ground but I go quicker on steeper rougher sections, just personal preference. Haven't had a flat in about 6 months too
[Reply]
  • + 9
 Useless article. Didn't tell me anything that I'm sure 95% of riders know. We know high and low have their tradeoff, I was looking for some insight into optimum pressure suggestions for different terrain. My problem, with most DH tires if I don't run 35 or higher, it's pinch flats like crazy. I'm usually running 40psi in everything. I'll give up a bit of traction to avoid walking my bike down the run...
  • + 1
 get dual ply tires and thornproof tubes. I ran those for 3 years and never got a flat once. And I could run 30 psi easy
[Reply]
  • + 9
 The comments make for a better article than the article itself. I read it looking tyre pressures run by pros in wc maybe....just for the curiosity, but I will run pressure with handometer anyway hahaha
[Reply]
  • + 11
 so what psi do i run ?
  • + 3
 Thanks Bro!
  • - 3
 i never run anything over 23-25 unless @ places like Ft Bill where you reaslly need hard pressures, then i will head to 40 thereabouts.

reccomended tyre pressures always seem very hard to me.

although that is DH tyres. XC tyres have to be pumped up more obviously
  • + 2
 The guy asks how much psi he needs and gets a +7 props?? We sure are generous today, I'll make it +8 !
  • + 2
 if it wasn't for the postage i'd send you a beer!
  • + 0
 Whatever pressure you choose just make sure you have 4 to 7 psi LESS in the FRONT tyre (as many posters above and below will attest). Firstly, because you need more protection for the rear tyre from pinchflats and rim hits, and secondly because you want more grip on the front tyre. You want more grip on the front tire because if you have the choice of one of your tyres losing traction, it is safer/easier/less frightening when it is the rear.
  • + 3
 "It's safer...when it's in the rear"
That's what she said! Wink
  • + 1
 If its in the rear, its usualy "that's what HE said!"
[Reply]
  • + 4
 There wasn't really any useful information in the article. Does, however, confirm my method of finding "correct" tire pressure: Front should be high enough that it doesn't squirm. Rear should be high enough that there aren't any rim strikes. The trouble with flat out recommending that, or creating a chart is that there are too many variables. What weight is the rider? What trails are being ridden? And what rim/tire combo?
  • + 2
 Agree with socratease. There are a lot of variables, but if you are a tire manufacturer don't you need a pretty good idea of what pressure works best in various situations just to test the tires? They could provide some more helpful data, even if it's just sample points like what pressure factory rider X likes for course Y, with rims Z, etc. Give people a starting point at least, like what Fox does with shocks. As it is they provide pretty much no help to amateurs like me who are not good at figuring this stuff out by trial and error.
[Reply]
  • + 4
 I have noticed this psi diffrance with my tubeless setup. I've run my raceing Ralph tyres at 37 psi thinking that will help roll faster well in a way yes it does but I've noticed you loose forward drive more so on the ups. I dropped my psi to 31 or there abouts and I seem to get more drive forward . So lower psi allowes the side grip of the tyre to bit giving more drive forward . So if you think I'm going to tell you what psi you should run think again becouse it's down to the user prefrance really of course it has some basic rules but all tyres behav difrantly .evan the same tyre behaves difrantly to one rider to the next . Find your own balance it takes a while but get to know your tyres play with psi don't be afraid to try a lower psi before you scream these new tyres are crap :-)
  • + 1
 Please use spell check. Lgi
  • + 1
 Sorry was in a rush
  • - 8
 Downhilladdict - grow up and maybe get a life
  • + 1
 Well that escalated quickly
[Reply]
  • + 5
 Funny about them using a GEAX tire for the cover photo, pretty sure no matter what you do with those tires the average flat tire still has better traction #worsttiresever
  • + 5
 You know the interview is with someone from Geax?
  • + 1
 yeah... but he kinda right, the rubber is harder than the rock your riding on... reverse approach maybe? the rocks stick to the tire instead of the tire to the rocks? haha
  • + 1
 I had a set of Geax Sugaro (whatever, too hard to spell) with the white walls and they were their soft compound.

I REALLY liked them - closest thing to Maxxis Super Tacky I've found.
[Reply]
  • + 6
 There's also the slight weight increase to take into account with higher pressures...
  • + 5
 That's why you inflate with helium.
  • + 1
 Helium has way lower density than air, so you may end up with even heavier tyre with the same pressure Wink
  • + 1
 Helium is a smaller molecule than nitrogen or oxygen (which is what makes up the majority of normal "air") and in fact, smaller than the rubber in your tubes/tires is meant to hold.
  • + 1
 So basically the helium will soak thorough the rubber and the tire will look like a limp party balloon in no time flat.
  • + 1
 Atomik888, that's actually not a joke. A bmx buddy of mine at the skatepark says he can feel the weight difference in his tires between running 100psi versus 80psi. The higher psi actually makes his tires rotationally heavier and slower to accelerate. In a skatepark where it's pretty smooth you'd think otherwise. I would have called bullpoopoo but I don't have the personal experience to question his observation.
  • + 4
 You should go ahead and call bs. 1 mole of atmospheric air is 22.4 liters and has a mass of about 15 grams at standard temperature and pressure (1 Atm, or 1 bar, or about 14.5 psi). The amount of air needed to increase a BMX tire 20 psi is about a liter(3 or 4 strokes on the average floor pump). If your friend can truly feel less than a gram, then he is part cyborg and should be destroyed!
  • + 1
 Thanks, Fattyrephreak, that's the kind of info I wanted.
[Reply]
  • + 4
 my mate got a puncture today, we didn't have anything else so we stuff it with grass and carried on riding, would recommend if you don't have repair kit to do that Razz
[Reply]
  • + 2
 My 2.2 rubber queens state something like 40min 60recommend, I put 60PSI in and bounced off every rock, root and stone on the trail on that run. Needless to say they went to 30PSI very quickly after that and they are a much better tyre for it. I was ready to heave them into a skip after that first run.

Why would you tell me such lies conti? all it does is make the tyre feel crap and put people off using them, if you put a 30-35 recommended on them then I'm sure more people would be hooked on the first ride.
  • + 1
 With every tire and brand, there are different Min and Max Pressures. 60 PSI is most deifinitley your maximum pressure and is there to allow the bead to seat properly on the rim when mounting it. It also be a warning not to exceed this pressure, as pressures can increase due to altitude and temperatures. Having checked my pair they don't tell you to run them at 60.
[Reply]
  • + 2
 It's only when you ride somewhere totally brutal you understand the need for higher pressures .
Did la fenasosa last year and after three impact punctures on the first few runs realised my pressure (that I've been running pretty much the same for years) might be way too low. I now run my tyres about 10psi higher than I used to and find most brands to be a lot more consistent.
Running about 45 psi in most things but I am around 120kg
[Reply]
  • + 1
 I'm using stan's flows and Shcawbe tubless ready tires. 2.4 Rocket Rons is my current choice. 19 psi front 24 psi rear and let them go down to 15 psi front and 19 psi rear. I am riding in Abbotsford, so on dirt and not too rocky like the North Shore
[Reply]
  • + 1
 Ok inventors and innovators here's a challenge. I run tubeless. My local ride is a single hill meaning a climb then a descent so ideally my pressure is higher for the ascent and lower for the descent. If I do this I need to let some air out at the top. no problems with this. but to climb again i need to re-inflate. The fresh air sends the latex off a bit each time until no liquid is left. Any suggestions appreciated. ?
[Reply]
  • + 4
 But... but... we're supposed to run 30psi in our Minions and not care about other people's opinions, right?
  • + 1
 Yes, pretty much. You can't go wrong with 30psi Minions. Still waiting for a company to come out with a comparable tire that is less expensive, but it hasn't happened yet!
  • + 2
 The Bontrager G4 is a direct copy and apparently made by Maxxis yet it cost about twenty to thirty bucks less. I'd say that fits your requirements.
  • + 1
 Thanks, ill check them out.
[Reply]
  • + 1
 There are a lot of ignorant people on here saying things like " 30psi and I don't care about anyone else's opinion". Chill out! If you don't want anyone's opinion then don't give your own. People are having discussions about the pros and cons of different presure applications and its a good idea to take into account all that is said. I personally have taken on board the idea of inflating to about 50psi to set the bead and stop the little bit of tyre wobble. Cheers chaps
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  • + 2
 Rider weight: 195 lbs; F Specialized Hillbilly/ R Butcher 1.8/2.0 Bar (27/30 PSI) running lightweight Foss Tubes . Never had a pinch flat in 2 years riding DH tracks in the Alps and Whistler...
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  • + 1
 Going tubeless does not save weight. UST Tires and systems are just as heavy as most tire/tube combos. Also running sealant, try weighing a the amount of recommended amount sealant you need for a tire, it weighs as much or more than a tube some times.
  • + 1
 You're a bike scientist!
  • + 1
 Yeh I'm not convinced my tubeless setup is much lighter but it lets me run at lower pressures which I appreciate despite the hassles of tubeless. However I have experimented a bit and tubeless does def feel different at the same pressures.
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  • + 1
 I have never ever measured my PSi in a bike tire once, I go by feel and look, if it looks to rolled out when I am on it I add some air, ride and see how it feels, if its dry as a bone I jam the MF with air and ride faster than humanly possible.
  • + 1
 If you've never measured the PSI in your tires you should try it. It's one of the most noticeable things you can change in your bike setup. It's very useful for attacking different types of terrain.
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  • + 1
 This is a good subject for all riders to think about. I been dealing with tire preassue, rim width, tubes, tubeless for many many years. This subject already solved for me but is something I think about alot. Noooo riders really need to read this and learn alot.
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  • + 1
 Good article. Tire pressure is a great tuning tool. Skiny people, smallish tires like Minion, High Roller, biggies Schwalbe or Kenda with more airvolume to play. Outdoor temperature also important for grip and wear. On a hot day on a rocky and steep track in the alps, bit more tirepressure. Minion Supertacky dies but grip is great till its demise.
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  • + 1
 After 13 years on DH bike (I am 160 lb) and i try a lot of set up
Minion front 2.5 3c tubeless at 31psi (tubeless for the weigh)
Minion rear 60a with tube at 35 psi (60a to have equal wear in front and at the rear and tube for toughness on tail bashing)

Make your own iteration but... mine is set!
Good ride
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  • + 0
 I used to ride my minnions at 30 psi on suggestion of a guy who thinks he knew every thing, and the results were, always braking my rims. I decided to do it my way and run them at 50 psi, and I learned one thing that control and speed were all in my head not in low pressure tires, if you stop thinking about this small things you will ride better ;-)
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  • + 1
 40/40 psi on WTB Vigilante 2.3 for trail and all mountain is pretty much the best I tried so far. Never flatted in 2 years and you get much more rolling without compromising grip.
  • + 1
 Go tubelesss.
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  • + 4
 I run 70 PSI in my tyres... Inb4itsadirtjumper
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  • + 4
 Conti rubber queens 32psi rear 30psi up front. Best all mountain tyre ever
  • + 2
 Finally someone agrees with me ^^^
  • + 1
 32, 30 sounds a bit high as you don't hit the turns that hard to be honest Smile and you have all that suspension too Frown but then you do carry a bit more weight around the middle than me I suppose Big Grin
  • + 1
 I have found you can run lower pressures when riding canal paths and fire roads. Be careful of those potholes Rick
  • + 1
 Nah Nick, Big Grin I think it was when I was sat behind you on those trails you took me to, you know, when I was on my hard tail and you was on that super star carbon everything dream machine. I had time to look at your rear tire and just put two and two together. Four!
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  • + 4
 "Power is nothing without control": Pirelli.
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  • + 3
 More of these articles please! Always learning something new everyday Big Grin
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  • + 2
 I dont understand how people manage to run 20-30 psi even wirh tubeless. I still destroy tyres!!!
  • + 2
 They are probably lighter riders. Im 99kg so I usually run around 30psi. I would absolutely destroy rims at 20spi, LOL.
  • + 1
 but I'm only 66Kgs
  • - 1
 I pinch flat right through the tyres. I need 35-40 in the front and 30-35 rear.. conti der kaiser 2.5
  • + 2
 I'm mystified as well to the author not even mentioning the riders' weight. I go about 220 lbs. and some skinny XC racer would probably use the same pressure as I use for DH.
  • + 1
 Only guys that look like sticks can get below 30 unless their on full DH wire beads. At 30psi, I can roll a Nevegal right off my DT 5.10 with my hands.
  • + 1
 Because they never hammer a turn.
  • + 1
 Ive ripped/roosted tyres off the rim before, since ive swaped to Maxxis tubeless specific ive had no problems. I weigh 65kg and have run 18-20psi before no worries.
  • + 1
 I regularly run 25PSI and have gotten away with 20PSI on a few occasions.
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  • + 3
 Minions - 28 front 30 rear Maxxis tubeless xc - 25 front 30 rear
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  • + 3
 Ardent 2.4 at 25psi front, Crossmark 2.1 at 30 psi rear...29"
  • + 1
 Sounds like spandex conditions
  • + 1
 If you ask nicely...!
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  • + 2
 Pirelli: "POWER IS NOTHING WITHOUT CONTROL".
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  • + 1
 easy, for me (i run slime tubes) its as low as possible, without getting pinch flats when hitting rocks...
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  • + 2
 Sorry but this was absolutely no help.
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  • + 3
 Pump em up stfu.
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  • + 1
 i run what feels nice, as i don't have a pressure gauge, quick squeeze and thats good enough for me
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  • + 0
 i went from 40 psi to 15 psi in my bontrager xr4 team issue tubless which i like .so now i pump them up to 35 on the way up the trails and let some out for the way down .
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  • + 2
 Hans Dampf 20 psi in the front..... sticky goodness!!!!!
  • + 1
 I run the same as you. 19-20 in the front. 24-25 in the rear. Hans Damp in front Rocket Ron in the rear. One thing I will say about running low pressures is I must check tire pressure near every ride. With these low pressures it is easy to get too low and roll your bead off. except with my Easton Carbon Havens. I have trouble changing tires they are so tight. I weight 185 lbs.
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  • + 2
 What's with the italics
  • + 2
 Someone didn't close the italics...
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  • + 1
 what PSI should you put in a DH tire?
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  • + 1
 I ran 18 psi in my minions once, very grippy indeed
  • + 1
 haha i can vouch, but they didnt fair too well in the bowl im afraid
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  • + 1
 This is all i usually see from XC riders. Pissing around over 2 PSI
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  • + 1
 What a good psi for dirt jumps/street
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  • + 1
 I'm pumped, gonna go ride my mt.bike and get some fresh air!
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  • + 1
 great article! thanks!
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  • + 1
 45 in my eskars!
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  • + 0
 Run em hard as fuck all year round, none of your psi reading pish
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  • + 0
 interesting article. tnx pinkbike
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