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  1. #1
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    Tire pressure - Bend

    Hey Bend riders, how much pressure do you run? I am coming down from Canada and with all the rock etc. I run around 40 psi, but with the flow of Bend I'm thinking it should be less. Thoughts?

  2. #2
    Nat
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    I think the "right" tire pressure depends on a lot of things, including tire size, body weight, how aggressively you ride, how much suspension travel you have, tubeless versus tubed tires, etc. so the best way to find out is to play with your pressures once you're here.

    On my bike with 2.1 inch tubed tires I run close to 40 psi, but on my bike with 2.3 inch tubeless tires I run more like 25 PSI.

    Have a great time in Bend!

  3. #3
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    I run around 25 psi (tubeless) 2.2" Geax AKA tires. I am 5'11" around 160# on 20# XC bikes. 40 psi and I would be bouncing all over the place.

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    Tubed I'm running 35-40 PSI. Will be dropping to 30 or less when I go tubeless.

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    I must be an exception. I run pretty high pressures. Both my Singlespeeds (29er and 26er) hardtails run beautifully at 35-40 PSI. I tend to run a higher pressure in the rear as opposed to the front. I run Schwalbe Rocket Ron's on both bikes. My new build 29er Carbon Hardtail will also have the Rocket Ron's. They run great around here. Plenty of grip. No doubt the sandy corners sometimes get twitchy, but overall the trade off of the higher pressures works well for me on climbs. And judging from my Strava times, it must be working well. The responses here also depend on your riding style and technique.
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    Quote Originally Posted by willem3 View Post
    No doubt the sandy corners sometimes get twitchy, but overall the trade off of the higher pressures works well for me on climbs.
    yup

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    Run Specialized a 2.3 Ground Control on the front and a 2.2 Fast Trak on the back; using the Control casing. I have this setup on my A9C SS and SJ HT. Front PSI is set at 21-22 and the rear is at 23-24. I am 6' and 160# or so. I have tried higher pressures, but I was not happy with how the bikes behaved.

  8. #8
    Daniel the Dog
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    Eat a bit would you

    Quote Originally Posted by Dry Side View Post
    I run around 25 psi (tubeless) 2.2" Geax AKA tires. I am 5'11" around 160# on 20# XC bikes. 40 psi and I would be bouncing all over the place.

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    Schwalbe knobby nic 2.35 up front at 22 psi and wtb weirwolf 2.3 at 25 psi rear. Both set up tubeless.

  10. #10
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    A lot of the somewhat-techy stuff you'll encounter are rock gardens with small to medium size stones and roots. If you run much over 27psi, particularly in the front, you'll deflect off them and have difficulty holding your line and/or potentially have troubles.

    You can run your suspension soft to compensate, but the efficiency loss isn't worth it IMO.

    A typical tire setup is something in the 2.2-2.4 range run tubeless at ~24-27psi F and 26-30PSI rear (given ~ 165lb rider). Ikons, RR's, Slant6, plenty of options.
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  11. #11
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    I'm gonna try an keep my opinions simple, based off what I ride in different terrain, and around here, etc....

    I'm 190lbs, and try to save my rim's/tires, and can usually put the tires exactly where I want. Around here, I generally run 30psi front 35psi rear with lighter AM tires tubeless. A little higher than "needed" as I can't trust squirmy tires. Just got back from a real high speed ROCKY race, and even with full DH tires on my AM bike I ran 38psi rear 32psi front.

    I set my 125lb wifes tires up about 25-28psi front, 28-32psi rear, with 2.4 tires and strong rims tubeless, as she just mashes straight into things lol.
    Bend, Oregon

  12. #12
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    Thanks for all the responses everyone - very helpful! After reading the comments, I think I might be the only one in Bend that is riding tubes!! hahaha...

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    Nat
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    Quote Originally Posted by darcymullin View Post
    Thanks for all the responses everyone - very helpful! After reading the comments, I think I might be the only one in Bend that is riding tubes!! hahaha...
    Going tubeless in central Oregon gives dubious benefit, in my opinion. There are very few thorns around here and most of the trails are pretty smooth so the risk of puncture is pretty low. The drawback is that if you decide you want to switch to different tire, it's not a simple operation of popping out a tube, switching rubber, then reinflating the tube. You have to reapply Stan's, use a high-pressure air compressor, and hope you don't make a huge mess on the garage floor. Then you have to wait to make sure that the Stan's "takes." I converted over to tubeless years ago because everybody told me that I had to, so I did.

  14. #14
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    I agree with Nat. For Bend, tubeless........ ehhhhhhh....... Not a huge advantage, when you take in the hassle.

    If it were more rocky(snake bites), or more thorns, I would say tubeless 100%.
    Bend, Oregon

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    Running tires tubeless has big benefits, IMHO, especially if the tires are run a low pressure. Advantages include, for example: (1) pinch flats are eliminated; (2) decrease in rolling resistance due to lower pressure and elimination of friction between the tire and the tube; and (3) lower resistance means better traction.

    I haven't had to use an air compressor to mount tubeless ready tires for years. A standard floor pump does it for me every time. I also haven't experienced having to wait for the Stans to provide a sufficient seal. 1.5 - 2 scoops and spinning of the wheel seems to work fine. Actually, I find it is best to ride newly mounted tubeless tires immediately to get a perfect distribution of the Stans. Easy-peasy.

  16. #16
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    I run (carbon) UST rims and never had any problem with tubeless (using Stan's sealant) with standard tires (Geax AKA). Benefits SpryIP lists are great. The ride quality at low pressures is so good. Saving nearly a pound of rolling weight. It makes a 29er HT the preferred choice for central oregon trails.

  17. #17
    Nat
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    If you want to run really low pressure then tubeless is beneficial, but how low do you want to go? I ran 20psi in a 29x2.35" tubed tire (Panaracer Rampage) and never came anywhere close to pinching. Going tubeless might let me go down to 10-15 psi but I don't see why I would want to. Smooth riding technique and not ramming into stuff helps avoid pinching too.

    Rolling resistance from friction between tire and tube is one of those things that seem like urban legend to me. It must be negligible if not nonexistent.

    I have yet to seat a tubeless tire with only floor pump pressure. Maybe I need a tutorial because when I cycle the pump the air just leaks out of the tire.

    Weight savings is nice, especially on a 29" tire.

  18. #18
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    If you got under 25 psi for real rides and avoided pinched flats you are the man! I haven't managed that. I'm going tubeless to increase grip and drop some weight.

  19. #19
    Nat
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    Quote Originally Posted by StreamRider View Post
    If you got under 25 psi for real rides and avoided pinched flats you are the man! I haven't managed that. I'm going tubeless to increase grip and drop some weight.
    Does Phil's network count as "real?" I kept dropping the pressure just to see how low I could go but after 20psi the tire just felt mushy and slow.

  20. #20
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    If you are cruising through GS without any pinch flats you are the man. I've tried with tubed and its doesn't work for me sub 30. And even that is pushing it. I weigh about 155 dripping wet.

  21. #21
    Nat
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    Quote Originally Posted by StreamRider View Post
    If you are cruising through GS without any pinch flats you are the man. I've tried with tubed and its doesn't work for me sub 30. And even that is pushing it. I weigh about 155 dripping wet.
    The big question is, "How low would you want to go in your tubed tires if you could go as low as you want?" The premise is that ride quality and traction get better as you drop your pressure, but at some point you'll get diminishing returns so even if you could drop to 10psi, would it make things the riding experience that much better? I say no. After a certain point the tires will just feel mushy, draggy, and easy to roll over in corners.

  22. #22
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    I'm guessing 25.

  23. #23
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    My guess is that riding the beginning east sections of GS with tubed tires below 30 psi equals some likelihood of a pinch flat. I think that likelihood is increased a fair amount as the psi drops. I would not even try riding the rocky sections of GS with a tubed tire at 21f/23r, which is often what I have the tires of my SS set to. I do not go lower than that because the bike/tires start to behave funny with my riding style, and the same applies if I increase the psi. I increase the rear tire pressure on my geared HT to about 24 psi to compensate for the increased saddle time, translating to an elevated risk of rock strikes through the tire.

    Sorry that we have sabotaged this thread, which is now just a discussion related to tubeless vs. tubed.

    It is clear that MTBers have strong opinions about bike setup .

  24. #24
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    Not to get too far off topic, but obviously the greatest advantage of tubeless is weight. A light-weight 29" tube is ~225g, 1.5 scoops of Stans is ~50g. You're loosing about a pound of rotational mass at the extreme of the wheel's circumference, where again it matters wildly more than any other location on the bike. And that at a cost of, well, pretty much nothing.

    Those who can't mount tires tubeless are often trying to mount new tires, which are often absurdly difficult or impossible. Ride the for a week or two with a tube first.
    It's also much cleaner to get the tire to seat/pop in place with no Stans (Stans doesn't help there), then inject the Stans with the syringe tool. No mess...
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  25. #25
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    I find removing the valve core makes it quite easy to get even brand new tires to pop right on the rim. I then add the sealant through the valve, put the core back in and inflate to desired pressure and ride. Have not flatted since I switched to tubeless two years ago. I replace the sealant every few months.

  26. #26
    Nat
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    Quote Originally Posted by icsloppl View Post
    Those who can't mount tires tubeless are often trying to mount new tires, which are often absurdly difficult or impossible. Ride the for a week or two with a tube first.
    Hey, that's a good idea to use tubes for a few weeks first. I've always tried to mount tires straight out of the box and ended up with Stan's all over the place before I could get a good seat. Knowing me though, a few weeks could end up being an entire season.

    I can't recall having pinch flatted or punctured since I moved to Central OR over a decade ago.

  27. #27
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    Very rarely got flats here running tubes, but I switched to tubeless two years ago. Will never go back!

    I run 30-32 psi on both front (2.4) and rear (2.2). I weigh 210.

  28. #28
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    Quote Originally Posted by Nat View Post
    I've always tried to mount tires straight out of the box and ended up with Stan's all over the place before I could get a good seat.
    I like to pop the bead on the wheel and spray the bead with soapy water/windex/simple green, then add air. Once the bead seats, I'll pull the valve stem and squeeze stans in it (the 1 oz bottle works good if you trim the tip right and is cheaper than the syringe). Also, it helps to not have any weight on the tire. I like to hang the wheel on a hook so nothing is touching the tire until all is said and done. Haven't had a tire blow a load on me yet!
    The secret to mountain biking is pretty simple. The slower you go the more likely it is youíll crash.
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  29. #29
    Nat
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    Quote Originally Posted by woahey View Post
    I like to pop the bead on the wheel and spray the bead with soapy water/windex/simple green, then add air.
    How do you get the bead to seat on the rim without using air?

  30. #30
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    Quote Originally Posted by Nat View Post
    How do you get the bead to seat on the rim without using air?
    I don't. Looking at what I wrote, I made it seem that way though. I get the tire on the wheel, then spray with soapy water and then air it up to seat the bead. Once the bead is set, I can add Stans through the valve stem.
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  31. #31
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    Quote Originally Posted by icsloppl View Post
    Not to get too far off topic, but obviously the greatest advantage of tubeless is weight. A light-weight 29" tube is ~225g, 1.5 scoops of Stans is ~50g. You're loosing about a pound of rotational mass at the extreme of the wheel's circumference, where again it matters wildly more than any other location on the bike. And that at a cost of, well, pretty much nothing.
    You'd save about 1/3 of a pound using your #'s above, still probably noticeable though.

  32. #32
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    I run tubes 24-28 in front and 27-30 in rear. I'm 185 lbs naked. I ride GS, the rocky alt route on COD, voodoo, tiddly, all that stuff. I've pinched once and it was on a drop on tiddly with probably around 27 in the back. Also dented the shit out of my rim. Have since got a couple more major dings in rim (it's trashed now) without pinching. Maybe i'm lucky? *shrug*

    I'm also riding a 29er with 130mm travel in back. That's got to make life a little easier on the tubes than a hardtail.
    Bend, OR

  33. #33
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    Quote Originally Posted by willem3 View Post
    I must be an exception. I run pretty high pressures. Both my Singlespeeds (29er and 26er) hardtails run beautifully at 35-40 PSI.
    Uhh, I usually pump to 50 PSI front and 55 rear. Panaracer Fire XC Pro 2.1s, tubed, older 100mm travel XC bike. Pump back up by 40 at the lowest; lower than that feels awfully slow. Have tried wider, have tried lower, didn't care for it and went back to skinnier and higher. Better grip to be sure, but the slower handling isn't my thing. I pay for it in vibration, but so be it.

    A grain of a salt: I prefer a cyclocross to my full squish as the full squish feels like a boat in comparison. This is with a 71 degree head angle on both the squish and cyclocross, so the difference is mostly just the relative moments of inertia of a 32C versus a 2.1. It doesn't hurt the 32s are at 65-70 PSI, though.

    Can't say I'm looking forward to the probable phase out of 26 for 27.5 and resulting increase in tire weight and inertia (unsurprsingly, I am not a 29er fan), but hopefully a new mountain frameset is still a ways off for me.
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  34. #34
    newfydog
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    I thought tubeless was pretty stupid in C.O., until I tried it. Sort of like a condom, just feels better without.

    I run 25-28 lbs. There might be some mush out of the saddle, but I believe the tests which show they actually roll faster on anything off road.

  35. #35
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    Not sure how my post got here, meant t ostart a new thread.
    I only ride bikes to fill the time when I'm not skiing.

  36. #36
    love my Simonds 519
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    Quote Originally Posted by newfydog View Post
    I believe the tests which show they actually roll faster on anything off road.
    Happen to have links? I'm aware of the Schwalbe study which shows a moderate reduction in pedaling power requirement with reduced pressure and increased width for gravel, which is presumably not a horrible approximation of Bend's fairly buff, packed trails. The study's been criticised on a few counts, mainly inclusion of wider tires and tubless tires would make it more useful, but I've not come across an update or more complete mountain bike version. Data for road biking yes, plenty of it from Jobst Brandt and others, but the rolling resistance curves slope the other way for pavement.

    I suppose I should mention one factor influencing my PSI selection is I bike across town to the trails rather than driving to them. So a typical after work trail ride for me often has as much or more pavement than dirt. I'm not the sort to stop and futz with a pump when transitioning, either.
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  37. #37
    newfydog
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    Yep, that's one of the studies I've seen. They found a 2.4 tire at 21 psi saved 50 watts over a 2.1 tire at 57 psi. The study might have some detractors, but that difference is huge, so I doubt you could actually reverse the findings in a different study.

  38. #38
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    50W when riding off trail. Which is to be avoided as it widens the tread. And not representative of the majority of miles as those are on trail in normal conditions and present lower rolling resistances. Our frost hove tread in the fall or when you're one of the first riders up in the spring is probably in the direction of Schwalbe's off trail meadow data. But more relevant in terms of total miles ridden around town is likely Schwalbe's data implying someplace between gravel and pavement is a surface firmness where changing width and pressure would have negligible effect. Unfortunately the study doesn't describe the nature of the gravel tested so it's hard to reason about what rolling resistance curve slope Bend buff tack or soft over hard might typically exhibit.

    My guess is Bend's rolling resistance curves switch slopes, with narrower and higher PSI being slightly faster on buff tack and somewhat slower when conditions change over to soft over hard. This based on a variety of bikes, tires, and tread wear levels over the years I've been in town as well as a few decades of riding experience elsewhere. It's an unscientific observation limited to tubed tires in the 32C to 2.25 range. So I may be wrong or missing out on tubeless or high width effects. But I don't think reversal of Schwalbe's meadow results is required, just that Schwalbe's gravel be representative of the I don't know how many bajillion miles of the stuff I've ridden over the years.

    No links to other studies? Alas.
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  39. #39
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    I'd guess the fine gravel is a reasonable approximation of the buffed trails and the meadow is good for sand, blown out areas, and rockier trails.

  40. #40
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    I think it's very hard to isolate tire pressure / tire width. For me ~25 psi tubeless allows me to run 2.2" on a very light weight 29er hard tail and not be beat up like I used to be on a 26er running closer to 40 psi tubed. My times are faster. I tend to ride the trails available as the snow line and tree fall clears. Based on three hours a week on the spin bike power meter I can average about 250W/hr which comes out to 3.5kg/watt.

  41. #41
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    Indeed; one school of thought argues it's a mistake to try to isolate the two since a narrower tire needs to be run at a higher pressure to yield a comparable rolling resistance. For road tires this is well supported by measurements by Jobst Brandt and others. For mountain bike tires there seems to be a dearth of data but there's no reason to suppose the physics are fundamentally different.

    I did do a little searching this evening and found this MC Kramppi study. Kramppi unfortunately didn't look at pressure but finds a statistically insignificant correlation between width and rolling resistance, albeit in the direction discussed in this thread. This suggests tread pattern has more effect on rolling resistance than width, which would be an unsurprising result. And one in agreement with Kramppi's findings on weight and rolling resistance.
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