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  1. #1
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    Tire pressure reommendation

    I just got a Medium SC Hightower 27.5+ with Maxxis Rekon 2.8 and ARC 40 rims, tubeless. I am new to this and not sure how much tire pressure I should use. I have searched a number of forums but it seems like it is dependent on rider weight. I saw somebody had started a spreadsheet to help find a good starting pressure given weight, tires, size, etc. but the link was dead.

    So, I am 5,9, 170 lbs. I will be riding moderate trails as far as roots, rocks, etc. No jumps, no drop offs, nothing too aggressive. Just need a good starting point and can tune on my own as I go along. I can provide other information if needed.

    Thanks if somebody can help a brother out. And if I missed the golden thread somewhere just give me the link and I can read for myself.

    EDIT: Actual wheel specs:
    Rims: Race Face AR 40 27.5 32h
    Spokes: DT Competition (32)
    Nipples: Sapim Secure Lock AL Silver Nipples (32)
    Front Tire: Maxxis Rekon 27.5x2.8 EXO 3C TR
    Rear Tire: Maxxis Rekon 27.5x2.8 EXO TR

  2. #2
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    ASSuming your tires are actually 2.8" in diameter, I'd start with 18/16.

  3. #3
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    I have a new 27.5+ in the garage right now. I've heard of folks running 16 or 18. Maybe a tick above that for the 2.8's. I aired up the 2.8's to 21 or so the other day as I've been goofing off in the street to bed in the brakes and it felt quite firm.
    I think I'll ride the suggested 18/16 r/f and see how it goes. I may end up airing down on the trail. I'm tipping the scale around 160 so I'm not far from your weight. If you plan to ride aggressively on rocky conditions, perhaps a bit more to start and see how it goes.

  4. #4
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    I use to run 16F 17R on the rekon2.8

    Sent from my SM-G930V using Tapatalk

  5. #5
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    hmmm... i havw maxis rekon+ (27.5 x 2.8) and also nobby nics (2.8) Iat 175lbs...i usually run 13 front/15 rear. I have gone as low as 11 front/12 rear, this was by accident. I was too lazy to check pressure, and went for a ride. in the turns the tire or tires were starting to fold over. i have gone as high as 16/17 front & 18/19 rear.

    I have found 13/14 front & 15/16 rear to be the best for me on my bike and trails.

  6. #6
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    Quote Originally Posted by jacksonlui View Post
    I use to run 16F 17R on the rekon2.8

    Sent from my SM-G930V using Tapatalk
    Quote Originally Posted by Skyking1231 View Post
    hmmm... i havw maxis rekon+ (27.5 x 2.8) and also nobby nics (2.8) Iat 175lbs...i usually run 13 front/15 rear. I have gone as low as 11 front/12 rear, this was by accident. I was too lazy to check pressure, and went for a ride. in the turns the tire or tires were starting to fold over. i have gone as high as 16/17 front & 18/19 rear.

    I have found 13/14 front & 15/16 rear to be the best for me on my bike and trails.
    Thanks guys. I'm really surprised at how low the tires can be run. That said, I still have a hard time allowing myself to only inflate my 29x2.35 to 20psi.

    Are the conditions pretty rough that would cause any rim hits in your locations?
    Note: I am not the OP of the thread. Just also finding this info useful. One of these days I'll get to ride my new bike. haha

  7. #7
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    even when i went out on the really low pressure... i had not rims hits. Trails have typical roots, and some rocks. (but nothing like out west...i am in NY). But the psi that i use seems to give the best traction/grip. I would start out high, and then next time out, drop the pressure by 1psi. see how it goes. It is critical to have a good floor pump. I use the one with the dual guage (i forgot who makes it). but the one guage reads in single digits....the other is your typical scale guage. incase you were not aware.

  8. #8
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    Holy cow, I put about 22 lbs in my 27.5 2.8s and thought about adding a little more. I just went by feel and they seem a little soft (have not had a chance to ride yet). But, never have ridden or had anything close to tires this big, been many years since I have been on a mountain bike. Looks like I was way off, thanks for the feedback on typical pressures for this type of tire.

  9. #9
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    Running pressures like these where a psi or two can make a significant difference you need a gauge that's precise in this pressure range. A 0-30 psi Meiser Accu-gage can be used to reproducible set pressures to within 1/2 psi or better.

    That's not necessarily accurate to 1/2 psi, but reproducible and relative withing a 1/2 psi.
    Do the math.

  10. #10
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    This is what I run on my
    Ibis Mojo 3 (I weight 165lbs):

    Reynolds 40mm rims/I9
    2.8 Rekons F/R tires
    13 psi front/ 18 psi rear

    Ibis 742 35mm rims/CK
    2.6 Forkaster F/R
    14 psi front / 19 psi rear

    I like the 2.6 Forkaster on 35 mm rims better then the 2.8 on 40 mm rims. The bike is more planted, has less bounce and does not get knocked off line as easily.

  11. #11
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    Quote Originally Posted by tworst View Post
    I just got a Medium SC Hightower 27.5+ with Maxxis Rekon 2.8 and ARC 40 rims, tubeless. I am new to this and not sure how much tire pressure I should use. I have searched a number of forums but it seems like it is dependent on rider weight. I saw somebody had started a spreadsheet to help find a good starting pressure given weight, tires, size, etc. but the link was dead.

    So, I am 5,9, 170 lbs. I will be riding moderate trails as far as roots, rocks, etc. No jumps, no drop offs, nothing too aggressive. Just need a good starting point and can tune on my own as I go along. I can provide other information if needed.

    Thanks if somebody can help a brother out. And if I missed the golden thread somewhere just give me the link and I can read for myself.

    EDIT: Actual wheel specs:
    Rims: Race Face AR 40 27.5 32h
    Spokes: DT Competition (32)
    Nipples: Sapim Secure Lock AL Silver Nipples (32)
    Front Tire: Maxxis Rekon 27.5x2.8 EXO 3C TR
    Rear Tire: Maxxis Rekon 27.5x2.8 EXO TR
    This is really really tough information to gather from an internet query.

    Some people have been riding a long time, but they suck, or they're cautious, or they hang off the back of the bike and never learned how to read the trail ahead. These folk are going to ****in love plus tires and offer really weird pressure advice.

    Some people are gonna be fat and competent riders, or really good riders and maybe heavier than you. They live in the mountains. They're gonna say plus tires are shit, or suggest really weird pressure advice.

    Then other folks have the right blend of terrain, skill set, experience... who knows! Plus tires are AMAZING for them and their riding is on-point. ...And they're gonna offer advice that may or may not suit your needs.




    ...Add to that that being a self-proclaimed 'nothing too aggressive' guy you might be extra abusive or cautious, or have some serious skills deficits... who knows? Not to mention that plus tires are amazing or shit depending on terrain, or that ARC's are good rims but not very impact resistant....


    I think 19/23 is a good starting place, and that you should ensure your tires are right there every single ride... then mess with it after you are totally happy with your suspension tune and cockpit set up. (tire pressure and suspension set up are interrelated) If you're progressing you'll need to reevaluate your tire pressures as you improve.


    To a certain extent this is something you have to figure out for yourself. ARCs aren't overbuilt, so be a touch conservative.
    "Things that are complex are not useful, Things that are useful are simple."
    Mikhail Kalashnikov

  12. #12
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    You can start wherever you want if you have a good gauge and take a small frame pump to the trails. Keep lowering until you get feedback you don't like. Like rim hits or foldover or squirm. Then add a pound or half a pound and test more. Trail surface and the speed you can run will impact pressure. Rim inner width will impact. Sidewall flexibility will impact. Rider weight.
    It's a pretty linear experiment with a limited small number of options to investigate. Some responses can suggest other choices to consider. If you're getting sidewall foldover a wider rim could give more sidewall support and allow the sidewall to wrinkle and maintain even more traction instead of foldover. This is wrinkle-




    At medium non DH speeds I'd expect 11-14 front and 3-4 more rear or more because of higher rider weight on a 40mm inner rim. 45-50mm may avoid foldover for some tires at some speeds and trail conditions for true 2.8 and 3.0 tires. Think these are too wide and the pressures too low? Talk to the guys on the fat bike forum.

    With a gauge and pump you have to set your tires up for the worst segment of your ride.

  13. #13
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    Quote Originally Posted by scottzg View Post
    This is really really tough information to gather from an internet query.

    Some people have been riding a long time, but they suck, or they're cautious, or they hang off the back of the bike and never learned how to read the trail ahead. These folk are going to ****in love plus tires and offer really weird pressure advice.

    Some people are gonna be fat and competent riders, or really good riders and maybe heavier than you. They live in the mountains. They're gonna say plus tires are shit, or suggest really weird pressure advice.

    Then other folks have the right blend of terrain, skill set, experience... who knows! Plus tires are AMAZING for them and their riding is on-point. ...And they're gonna offer advice that may or may not suit your needs.

    ...Add to that that being a self-proclaimed 'nothing too aggressive' guy you might be extra abusive or cautious, or have some serious skills deficits... who knows? Not to mention that plus tires are amazing or shit depending on terrain, or that ARC's are good rims but not very impact resistant....

    I think 19/23 is a good starting place, and that you should ensure your tires are right there every single ride... then mess with it after you are totally happy with your suspension tune and cockpit set up. (tire pressure and suspension set up are interrelated) If you're progressing you'll need to reevaluate your tire pressures as you improve.

    To a certain extent this is something you have to figure out for yourself. ARCs aren't overbuilt, so be a touch conservative.
    Many insightful comments here. I should explain that I am new to the new bikes, suspension, geometry, tires, etc. I did MB from about 2000-2007. My last bike was a stump jumper fsr xc pro, 26 x 1.7 tires, maybe 3 in" of travel F and R, 3x9, no dropper. As far as skills, it took me 3 or 4 years to get to mediocre, meaning just keeping up mid pack as far as endurance. I ride in WV and its just up and down all day. Staying on the bike without having to walk it and missing trees was half the battle. My handle bars were are 580mm. The trails I rode were often just a nightmare of ruts, roots, rocks, mud holes, etc. So I have (had) some basic skills.

    Funny, I started out just looking for a gravel bike for some easy road riding.
    Somehow ended up getting a FS MB. Apprehensive about getting into MB again, but the bike is so damn awesome looking......... Only got the 27.5 because I found it on 30% sale. Yeah, I did read a ton on suspensions and tire sizes, but thought it wouldn't matter much just starting out again and I can change later if I need to.

    I say that I am pretty conservative only because I have been out of MB for so long and I am older now and have to think about injuries. I am the type that used to push it sometimes beyond the capability of my bike and myself and really was just lucky to get away with it. Green trails for me for a while. If I progress and desire to go more technical, I will have a bike that can do it. And if not, I will still have a cool looking bike with bad ass looking tires that I don't need. Either way should have some fun and get some exercise which was the point of getting a bike.

  14. #14
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    Quote Originally Posted by tworst View Post
    Many insightful comments here.
    Flattered you quoted me. I don't have anything to add to my previous reply. In general i'm a bit of a plus tire hater, but that's because of my own weight, terrain, and skill set. I like them in principle. Best advice i can offer is to be aware that big tires interact with geometry and suspension tune. While you can 'phone it in' with that stuff on a normal mtb, plus bikes leave little room for error.
    "Things that are complex are not useful, Things that are useful are simple."
    Mikhail Kalashnikov

  15. #15
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    Quote Originally Posted by scottzg View Post
    Flattered you quoted me. I don't have anything to add to my previous reply. In general i'm a bit of a plus tire hater, but that's because of my own weight, terrain, and skill set. I like them in principle. Best advice i can offer is to be aware that big tires interact with geometry and suspension tune. While you can 'phone it in' with that stuff on a normal mtb, plus bikes leave little room for error.
    I was told some time ago that flattery gets you stuff..............

    Anyway, what I was trying to say is that from your previous comments there seems to be a lot of different ideas on 27.5+ pressure and whether people like them or not. I just gave my experience level because you said there wasn't much to go on to give me advice. But wasn't really expecting anything more, just need to go out and ride some and play around with it. I will be doing easy stuff and it won't matter too much. Can adjust as I go. I will start out higher pressure and drop from there.

  16. #16
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    Quote Originally Posted by tworst View Post
    I was told some time ago that flattery gets you stuff..............

    Anyway, what I was trying to say is that from your previous comments there seems to be a lot of different ideas on 27.5+ pressure and whether people like them or not. I just gave my experience level because you said there wasn't much to go on to give me advice. But wasn't really expecting anything more, just need to go out and ride some and play around with it. I will be doing easy stuff and it won't matter too much. Can adjust as I go. I will start out higher pressure and drop from there.
    Makes sense to me. Also don't change pressures very often; give yourself enough time to really get used to the bike at one pressure, and then change it. If you're working on your technique and progressing as a rider you'll need to revisit your tire pressures a couple times. At first that will mean raising them, but later it can mean taking some air back out.
    "Things that are complex are not useful, Things that are useful are simple."
    Mikhail Kalashnikov

  17. #17
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    I had nearly 20 psi on my first ride. The rear was quite bouncy.
    The front was pretty harsh. That was just a ride to get to a nice location for a photo shoot. I rode one really rough rocky (mountain rock, not loose) downhill. I was riding on a pogo stick and needed to hang on for the ride.
    I've lowered the fork pressure about 10 psi and the tire pressure a few psi.

    For the next ride it was a 30 minute climb then back down the hill.

    The bike handled great -but it was different than my full suspension. So much that I felt like I was going really fast, and I was a minute off my PR on a 10 minute downhill (with only a few pedally bits).

    I'd be surprised if I had as much as 18PSI in the tires. Maybe close to 18 in the rear, slightly less in front.
    I may drop pressure for similar trail conditions for the next attempt.

    So far, if it's not a horrid rocky loose trail condition I can see 16 being a good starting point.

    Having the fork properly setup will be important too. With 10psi too much (or whatever), I had to slow rebound by 2 clicks. Which is crazy because stock it came 5 click open. That helped the pogo stick feeling. Once I lowered the fork PSI I opened the rebound back those 2 clicks. I haven't been on that type of technical section since to give it a fair comparison.

  18. #18
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    Update:
    I've been running right about 15 psi (according the the built in gauge on the Specialized floor pump) in the front tire and it seems about right. Maybe a touch more on the plus side of the "line" representing 15. haha

    The rear tire is a bit more of a challenge. I had right around 15 (same gauge position as the front tire) but I've had 2 rim hits at various times, in conditions that surprised me. I must have hit a rock that I assumed I'd miss.

    This afternoon I aired up a few extra psi in the rear. We rode a rocky area (embedded rocks). When I didn't carry enough speed, the rear end was quite poppy and bouncy. I had a hard time holding a line when just cruising around. Once I had the speed up it was fine and felt good. I may have had a hard hit, even at that psi. Each rim hit I've felt has occurred while out of the saddle too.

    It isn't likely I'll run less than 15 in the front but 15 in the back seems nice if not for harsh conditions.

    *I am on a hard tail*

  19. #19
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    Quote Originally Posted by Forest Rider View Post
    Update:
    I've been running right about 15 psi (according the the built in gauge on the Specialized floor pump) in the front tire and it seems about right. Maybe a touch more on the plus side of the "line" representing 15. haha

    The rear tire is a bit more of a challenge. I had right around 15 (same gauge position as the front tire) but I've had 2 rim hits at various times, in conditions that surprised me. I must have hit a rock that I assumed I'd miss.

    This afternoon I aired up a few extra psi in the rear. We rode a rocky area (embedded rocks). When I didn't carry enough speed, the rear end was quite poppy and bouncy. I had a hard time holding a line when just cruising around. Once I had the speed up it was fine and felt good. I may have had a hard hit, even at that psi. Each rim hit I've felt has occurred while out of the saddle too.

    It isn't likely I'll run less than 15 in the front but 15 in the back seems nice if not for harsh conditions.

    *I am on a hard tail*
    If you are worried about rim hits and like the low PSI, throw a insert into the rear and maybe even the front.

    Vittoria and Nukeprook have fairly light inserts that appear to work well.

    https://www.vittoria.com/us/air-liner-vittoria
    Nukeproof ARD | Nukeproof

  20. #20
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    Quote Originally Posted by In2falling View Post
    If you are worried about rim hits and like the low PSI, throw a insert into the rear and maybe even the front.

    Vittoria and Nukeprook have fairly light inserts that appear to work well.

    https://www.vittoria.com/us/air-liner-vittoria
    Nukeproof ARD | Nukeproof
    I'd never really considered an insert until I got this bike with the larger wheels.
    That may need to be a future upgrade though, I've having a hard time pedaling the beast as it is. Adding more weight sure doesn't sound helpful.

    I've never bought into the tire weight being a problem until I got this bike. I'm so slow that it's hard to recognize. I was on the other bike (2.3x29) and was hauling! I'm not generally fast climbing, but the speeds up a hill now is ridiculously slow and painful. haha

    At lest through the winter I'll be continuing to strengthen the legs riding this thing.

  21. #21
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    I'm running 25 psi front, 28 psi rear on 29x2.2 tires and I weigh 195 lbs. Any lower and the bike corners/handles poorly and bounces too much and I feel it sucking up my pedaling power, especially when I ride pavement to and from the trailhead. I'm not a fan of very low pressures nor of tires wider than 2.2".

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