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  1. #201
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    I'm 150 pounds, and ride a hardtail. 35-40 psi is perfect, things roll faster, and pinch flats almost never happen. If your skills are up to the decrease in traction, than its wll worth the extra pressure for low rolling resistance, and running less risk of fixing a flat tire (nothing slows you down more) Even with a tubless set up, ride at least 30 or more to avoid the bead rolling and breaking the seal.
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  2. #202
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    For those running tubeless this is Stan's recommended starting point: divide your weight by 7, then subtract one for front pressure, add 2 for rear. For me at 200 lbs that works out to 28 front and 31 rear.

    Note that this the recommended starting point and not a firm rule. I am running 23 front and 26 rear on Maxxis Ikon 2.2.

  3. #203
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    I just checked my pressure. Did a ride today with the dogs so it was pretty slow paced. Pressures are read from Specialized floor pump with gauge.
    16psi front- felt a little low, bottomed the tire once but no flat.
    20 psi rear.
    WTB Exiwolf 2.35 on Velocity Blunts

  4. #204
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    Quote Originally Posted by mobius911 View Post
    For those running tubeless this is Stan's recommended starting point: divide your weight by 7, then subtract one for front pressure, add 2 for rear. For me at 200 lbs that works out to 28 front and 31 rear.

    Note that this the recommended starting point and not a firm rule. I am running 23 front and 26 rear on Maxxis Ikon 2.2.
    That formula does not take into account tire width, which is a big factor. When I run the formula for me, I get very close pressures to what I use on 26"/2.4" tires. But on my XC bike that uses 1.9 tires, I use 10-15 PSI more.

  5. #205
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    215 lbs male

    I run 35 in front with 2.3's and 40 in back with 2.1

  6. #206
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    I usually run 20-25 PSI in my rear 2.0 tire. Tubeless 29er. Yesterday I bent the hell out of my Stan's Crest wheel going through an armored creek crossing at average speed. I was pretty shocked. At a 140 lb body weight I rarely have issues with wheels. I guess I'm going to start running 30 psi.

  7. #207
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    190lbs with all my gear. 28 psi in the front, 32 psi in the rear on 2.24's

  8. #208
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    175lbs and I run (pending trail and conditions) anywhere between 38 to 42. For the most part on faster trails the higher pressure and slower trail the lesser pressure.

    Mud I let a little out, sticky trails higher and dry usually I use the feel factor (if the tire is not sticking I let a touch out till it feels good)

    Can someone explain the "lower pressure the tire rolls faster" theory to me.......I dont get it :-/

  9. #209
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    Quote Originally Posted by spartacus View Post
    175lbs and I run (pending trail and conditions) anywhere between 38 to 42. For the most part on faster trails the higher pressure and slower trail the lesser pressure.

    Mud I let a little out, sticky trails higher and dry usually I use the feel factor (if the tire is not sticking I let a touch out till it feels good)

    Can someone explain the "lower pressure the tire rolls faster" theory to me.......I dont get it :-/
    Basically, on a rough surface higher pressures bounce more. the tire/wheel moves up more than forward.

    Lower pressure lets the tire conform to the terrain and maintain forward momentum.

    Same reason suspension is faster than rigid on rough terrain.
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  10. #210
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    Thank You. This makes sense
    I keep hearing this from some of the people out by me and it perplexed me because there was no explanation. I think they Just conveyed info they herd with out understanding why.

  11. #211
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    Quote Originally Posted by shiggy View Post
    Basically, on a rough surface higher pressures bounce more. the tire/wheel moves up more than forward.

    Lower pressure lets the tire conform to the terrain and maintain forward momentum.

    Same reason suspension is faster than rigid on rough terrain.
    No, that is not the theory. The theory is that a wider tyre is faster than a narrower tyre for MTB use because the longer, thinner contact patch requires the tyre to "lift" more than a fat narrow one. Schwalbe did a study looking at this and concluded as above. Some of the benefit is small (around 10watts IIRC) but some was surprisingly large. Depending upon the type of terrain. Note that on hard surfaces, (i.e. road bike) the opposite is true.

    WRT tyre pressure - as the decrease in pressure allows the above effect to occur, it will be faster, but at some point the extra drag of the bigger contact patch will have the opposite effect.

    Remember that simple physics means that the actual size of the tyre has no effect on the contact patch size - it is only the air pressure in the tyre. In other words a 26x1 tyre running 30psi will have the same contact patch size as a 29x2.3 tyre @30psi. The shape will change (long and thin vs short and fat), but the size won't. Generally speaking the long thin contact patch (narrower tyre) will have advantages in traction and braking, whilst the short and fat contact patch (wider tyre) will have advantages in cornering.

    This is why decreasing tyre pressure increases contact patch size which will improve traction due to the greater tyre surface area interaction with the terrain.

  12. #212
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    I am Mr 30 psi on both my Tubeless Ready Tire sets on both UST rimsets. Accidentally rode 25 psi tonight! I am now Mr 25 psi

  13. #213
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    I would add that pressures required depend on terrain. I did a 11 mile climb the other day on my steel rigid 8 speed, was great uphill with 40 rear 35 front. But then the washboard on the way down was crazy! I prob let out almost 20lbs on both wheels. Only way I could maintain control at speeds of 25-30mph. Had I had suspension with tubeless, I would have maintained the same pressures.

  14. #214
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    Quote Originally Posted by spartacus View Post
    Can someone explain the "lower pressure the tire rolls faster" theory to me.......I dont get it :-/

    Studies show you're faster when you can stay connected to the trail. Larger contact patch=more traction=faster
    Something wrong with your bike? Blame it on super human strength and sleep well at night knowing you are more than a man.

  15. #215
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    Quote Originally Posted by ZXFT View Post
    Studies show you're faster when you can stay connected to the trail. Larger contact patch=more traction=faster
    Also I would imagine some tire deflection over smaller bumps uses less energy than a harder tire transmitting that energy through the frame, suspension and even rider...
    just my two cents.....

    Plus more traction as stated above...

    My two cents .....

    Cheers,
    Paul

  16. #216
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    Quote Originally Posted by Rum Runner View Post
    Also I would imagine some tire deflection over smaller bumps uses less energy than a harder tire transmitting that energy through the frame, suspension and even rider...
    just my two cents.....

    Plus more traction as stated above...

    My two cents .....

    Cheers,
    Paul
    Makes sense. When suspension moves most of the energy is lost in damping.

  17. #217
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    Its kinda like the 29er argument: If it rolls smoother, it will be faster.
    Something wrong with your bike? Blame it on super human strength and sleep well at night knowing you are more than a man.

  18. #218
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    36 psi.. sounds pretty reasonable to me...

  19. #219
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    Quote Originally Posted by snowgage View Post
    36 psi.. sounds pretty reasonable to me...
    Reasonable to who? Riding what?
    It depends on tire width, terrain, rider weight, rim width, tube/tubeless among other things. Just for myself I run 22-40 PSI in different bikes (used on the same trails).

  20. #220
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    I weigh about 83kg and have been running 25 front/ 28 rear, Racing Ralph 2.25 tyres on loose/ rocky conditions. Managed to put a dent in my carbon Roval front rim on the weekend from hitting a rock so i'll be adding a few psi of pressure from now on. Bit less grip but better than destroying carbon rims.

  21. #221
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    Great post with lots of input. I read all the posts and did as some suggested and took my bike and floor pump with gauge down to my little single track loop with one steep and rocky descent with a narrow bridge at the end. I started with pressure in the upper 30psi range in both tires and played around. I ended up with 25 for the front and 28 for the back and the increased handling was great and very noticeable in overall control and less "bouncing" when compared to the higher tire pressures.

  22. #222
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    Prefer 25 psi on the front, 30 psi on the back.

  23. #223
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    im 170 lbs

    On a previous bike with 2.4 Maxxis advantages, I preferred 28 psi front, 30 rear

    I recently bought a Cannondale RZ 120 and went with 2.1 Kenda Nevegals. I prefer to be at 35 psi otherwise it feels way too squirmy in the corners. Although I find starting at 40 psi its noticeable too hard over roots.

    all tubed tires

  24. #224
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    3,5bar in Specialized Storm Control 26x2.0

  25. #225
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    3 bar in racing ralph 26x2,25

    But i might be way off.

  26. #226
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    Quote Originally Posted by Bech View Post
    3 bar in racing ralph 26x2,25

    But i might be way off.
    Does 1 bar = 15psi?

  27. #227
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    Quote Originally Posted by fsrxc View Post
    Does 1 bar = 15psi?
    1 bar = 14.5037738 pounds per square inch (no, i didnt know that off the top of my head. I used google)

  28. #228
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    14.5psi equals 1 bar

  29. #229
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    Some high pressures being run. I usually shoot for 28psi but I'll run 25psi if that's what it's leaked down too.

  30. #230
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    It really depends on the tires, trail conditions, and riding style, I can run from 18 to 30 front and 20 to 40 rear

  31. #231
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    run 50 psi

  32. #232
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    I'm 59 yrs old, 165 lbs, medium fast on the descents in Park City Utah. Primarily interested in climbing speed. I had been running 28 PSI in front (on a Yeti 575 with a 150 mm front fork) on a WeirWolf LT 2.55 and 30 PSI on a 2.30 Tioga Psycho Genius on the back (on Stan's Crest rims, tubeless). More than a 2 PSI decrease causes the tires to begin to fold under while cornering. I have now placed Conti X-King, 2.4 RS front and back, tubeless, and find I still need to run 30 rear and 28 front to get the same resistance to the fold under while cornering. I'd run lower pressure were it not for the cornering issue because it makes climbing a dream.

  33. #233
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    Cool-blue Rhythm

    155lbs - I am running ADventage tubeless and I ran 40psi back and front this week.
    I encountered some front wheel control issues on soft over hard, OK my lack of skills is probably the number one factor but my tire pressure may have been too high. I never had the same feelings when running 20-30 psi.

  34. #234
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    I'm not racing (yet), but been riding since the 90's. I started out running tubes and 50 psi back then and now I run tubeless and in the range of 23-26. I'm 160 pounds and have ridden Continentals pretty much all of the time with my preference now with Trail Kings with a 2.2 in the back and a 2.4 in the front. I've been experimenting with the tubeless version vs. the non-tubeless version and it seems even in the rocky and rooty areas that I ride that the lighter, non tubeless versions holds up just fine.

    After running tubes and high pressures and then no tubes and low pressure, I confidently feel there is no comparison between the two in terms of speed and confidence. I've also discovered that I can convert just about any rim to run tubeless with just stan's tape and a valve. One rim I had was stubborn and I had to add a layer of gorilla tape over the rim tape to get it to seal, but I think just about any crappy rim can be converted with the help of an air compressor.

  35. #235
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    Quote Originally Posted by vttix View Post
    155lbs - I am running ADventage tubeless and I ran 40psi back and front this week.
    I encountered some front wheel control issues on soft over hard, OK my lack of skills is probably the number one factor but my tire pressure may have been too high. I never had the same feelings when running 20-30 psi.
    Yes, 40psi in the front tire could be reducing traction and control.

  36. #236
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    25ish. I weigh 140.

  37. #237
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    Around 35 with 190 pounds on the bike. Much less and the tires squirm and squeal over obstacles.

  38. #238
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    I'm running 20psi front and 24psi rear with Specialized LK Control 2bliss tires in 2.0 width with Stans rim strips and a home brew sealant. I'm 160 pounds with an average riding style, no huge jumps or anything like that. I mainly ride on loose gravel/decomposed granite over concrete like hardpack.

  39. #239
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    Apparently, it also depends greatly on your pressure gauge. I finally got a good quality gauge. It's about 5 PSI lower than my floor pump and 4 PSI...in the other direction...from another tire gauge I have.

  40. #240
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    why are you guys running such high pressures? What kind of terrain are you running?

    I run 20ish up front and 25ish in the back. I ride sandy hard pack with roots and lots of pine straw and leaves. If I raise the pressure to 25 in the front it slides all over the place, the front washes out like crazy. If I leave it at 18 to 20 it rides great. I hit roots and large curb sized roots with no problem at all. I could not imagine running 30 or 40.

    I have a 2.2 ikon exo up front (or 2.4 ardent) depending on the weather and a crossmark 2.1 out back.
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  41. #241
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    The tires that are "high pressure" tires, such as the Maxxis Ikon, what are you guys running in them. I'm about 230# and riding in hardpack/rocky/loose over hp, with 29 x 2.2 Ikons. Should I just run them at the normal (for me) 35ish psi? Or should they be run with higher pressure. What is the advantage of having a high pressure tire?

  42. #242
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    Quote Originally Posted by smokehouse4444 View Post
    The tires that are "high pressure" tires, such as the Maxxis Ikon, what are you guys running in them. I'm about 230# and riding in hardpack/rocky/loose over hp, with 29 x 2.2 Ikons. Should I just run them at the normal (for me) 35ish psi? Or should they be run with higher pressure. What is the advantage of having a high pressure tire?
    I would definitly do some testing, start at 35psi and work your way down to where you'll get the most amount of grip without dinging the rims and or rolling the tires under, during hard cornering. I own Ikons also and weigh 150lbs with a 25lbs bike full riding gear is 175lbs total, I run 25-28 psi in mine front, and alittle more in the rear like 30-35 to help decrease rolling resistance , ran tubeless. On the road rides on my mountain bike I jack em up to 40psi

  43. #243
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    I'm 185lbs, running 35psi F 38psi R on Maxxis crossmark 2.0 with Dt Swiss X1600 rims for a few weeks since converting to tubeless, so far so good......climb better and no more flats........will try to lower a couple psi this weekend....see how it handles.....

  44. #244
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    We the people ...

    Are you all racing or something. I use too race and neve:crazy paid that close attention to PSI ever. All I have ever done was put in about 40 in remembering how hard or easy it was to sqeeze and go ride. Not that you can't notice a difference in a 3-4 psi change, but you would have to be tuned into your bike pretty well to notice it. Besides that if I were to run anything less than 30 psi I would get snakebit every time out.

  45. #245
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    Quote Originally Posted by redd4573 View Post
    Not that you can't notice a difference in a 3-4 psi change, but you would have to be tuned into your bike pretty well to notice it.
    IMO +/- 3-4 psi is a huge difference that doesnt require a 6th sense to detect.

    Quote Originally Posted by redd4573 View Post
    Besides that if I were to run anything less than 30 psi I would get snakebit every time out.
    Tubeless man... Its the way of the future.
    Something wrong with your bike? Blame it on super human strength and sleep well at night knowing you are more than a man.

  46. #246
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    Recommendations on pressure. Just got a '12 Dawes Haymaker 1200 17" with this setup

    Rims WTB Speed Disc Double Wall Aluminum
    Tires WTB Velociraptor Blackwall 26 x 2.10

    Sidewall says 40-60 so I put them at 50. I am 135# and a total noob. I ride mostly well packed gravel trail with a few pretty clear dirt trails with minimal roots and rocks. 50 felt good, but my hands were numb after a 15 minute ride on these dirt trails. I know there could a lot of other factors to that but hoping for a bit more cush if I lower the tire pressure.

  47. #247
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    At 135lbs I'd say you should be in the mid 20's psi wise. 50 is just crazy

  48. #248
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    180lbs... run 24psi front & 27psi rear in just about all my tubeless set ups no matter the tire (mostly schwalbe's)

  49. #249
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    Tubeless. 33 psi rear and only 16 psi front in a 2.25" tire - I have a rigid fork so it's my only suspension. Never burped... yet

  50. #250
    Heavylegs
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    Great at this rate we will be talking nito and beadlocks soon Now lets use our heads a little better than we have been . Tire makers have invested alot of $$$ in R&D, I personally run Panaracer Dart and Smoke Tube combo .I find they work for me. I run roughly 35-40 psi, I say roughly because I really only get as close as I need to be because most tire guages are very inaccurate anyways get any three different ones and try it. That being said the side walls on my tires read recomended psi between 30-50 psi. Now I'm not cracking on anyone's veiw on this topic but I believe the tire makers are spot on. I have had little issues with traction outside of poor judgement in placement of said tires. If you look at a correctly inflated tire from the approching angle it revels a crown, if one were to lay the wheel and tire at say 15 - 20 degrees to the left or right the contact area remains the same. And with weight on the bike say all of my 200lbs I could find the tires rolling a bit and increasing this area.Me myself and I believe that none of us would go out and deflate our motorcycle or car tires 10 -15 percent to GAIN traction??? I understand that this is not a great comparison but it's not to far off point. But the most important thing is we all have fun riding even if it seems goofy how others do things

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