1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    What tire pressure to use?

    OK, so I got past the number one noob question ("what bike to get") and bought a Giant Boulder SE. I have been riding it a couple times a week for about 5 miles each time for the past 3 weeks to get into a little better shape ("little" being the key word here!), but last night i noticed that the tires were bulging a bit with my weight. So, on to nooby question 2.

    What pressure should I put in my tires?

    I am 6'5" (dont worry; I got the 22" frame), and weigh in at 230#. I am riding the tires the bike came with (MTB Trail 26 x 1.95"), and have changed almost nothing on the bike (I just added some lights, a lock, a Thudbuster suspension seat, and an underseat bag), but I was wondering what the right tire pressure should be.

    I ride mostly on the road, but on my weekly rides I do ride a bit over grass and gravel (it's a shortcut to the Blockbuster through a golf flied, so nothing too rough). I do intend to take the bike to a couple of trails that are around my area (mostly technical from what I have read; no mountains in Miami, so there you go!). Should the tire pressure be changed for those trails?

  2. #2
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    Well, depends how much you weigh. I weigh 150 lbs and i ride at about 38psi... but i guess this doesnt help you much sorry! I ride with lower tire pressure to help cushion some of the bumps of the trail. If you dont plan on riding much trail, keep it at 60 psi. If you are going off road, lower it down to maybe 50 or so. To me, it seems like it makes a pretty big difference

  3. #3
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    They say you should ride the lowest tire pressure you can without pinch flatting. That is for the 'best' traction. However, the 'best' tire pressure will be different for everyone, as it will vary between riding style, riding surface, rider preference, the tire itself, etc. If you're riding on road, you probably want to be running higher pressures - maybe 50-60 psi or so. If you're riding off road, you'll want to find a pressure that works for you. This typically means experimenting and some flat tires.

    A good starting point for you and your weight might be 35 psi. If you pinch, add 5psi and try again. If you don't, drop 5 psi and see what happens. Repeat till you find that happy place.
    :wq

  4. #4
    don't thread on me
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    A fellow biker told me to always ride with tire pressure at 20% of your body weight.

    For the math impaired:

    150 lbs = 30lbs
    200lbs = 40lbs
    300lbs = what a clyde
    sign here ________________________

  5. #5
    tlg
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    Quote Originally Posted by jfrabat
    I am 6'5" (dont worry; I got the 22" frame), and weigh in at 230#. I am riding the tires the bike came with (MTB Trail 26 x 1.95"), and have changed almost nothing on the bike (I just added some lights, a lock, a Thudbuster suspension seat, and an underseat bag), but I was wondering what the right tire pressure should be.

    I ride mostly on the road, but on my weekly rides I do ride a bit over grass and gravel (it's a shortcut to the Blockbuster through a golf flied, so nothing too rough). I do intend to take the bike to a couple of trails that are around my area (mostly technical from what I have read; no mountains in Miami, so there you go!). Should the tire pressure be changed for those trails?
    Try posting this on the Clydesdales/Tall Riders forum. You may get more accurate responses from the big guys over there.

    Could also try the Wheels and Tires forum.

    It's a good question, but one which most smaller riders won't be of much help.

  6. #6
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    If you ride mostly on the road you want a higher pressure like 55psi to reduce rolling friction. This is also true for hard-pack. When you ride over logs or rocks I like to drop it down to about 38psi. If there is a lot of logs like erosion barriers, even less is good. Down to 25psi if you can. Here is the tricky part. For most of my rides there are rocks and roots, but it is also wet. So I ride 40psi in the rear for mud traction and 35psi in the front so I don't get bounced around on the roots.

    So to answer your question, 55 psi for roads and grass.

  7. #7
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    I'm about the same size as you (6'4", 225#), and I typically run 50psi in my 2.1" Kenda Nevegals.
    If you run a lower volume tire (even 1.95) I'd reccomend keeping your pressure high, or you're just going to flat all over the place if you don't take your butt out of the saddle. I used to pinch flat in the rear all the time because I'd get lazy and keep my ass on the saddle over sharp rocks. No troubles yet with the 2.1's. Also note the pressure ranges on the sidewall of your tire...they usually list the max psi.

    The benefits of low pressure: Shock absorption, and increased traction.
    The benefits of high pressure: Decreased rolling resistance, and decreased chance of pinch-flats.

  8. #8
    tlg
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    Quote Originally Posted by Roswell52
    A fellow biker told me to always ride with tire pressure at 20% of your body weight.

    For the math impaired:

    150 lbs = 30lbs
    200lbs = 40lbs
    300lbs = what a clyde
    That's a poor rule of thumb. It doesn't take tire width into effect.
    I run Hutchinson Pythons 2.0 @ ~30psi
    Panaracer Fire XC Pro 2.1 @ ~28psi
    Semislicks 1.5 @ ~50psi
    Slicks 1.0 @ ~80psi

    I weigh 175.

  9. #9
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    Thanks for all the replies! I think I will go somewhere in the 45~50 PSI range and then go from there based on trial and error...

  10. #10
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    The more volume in the tire, the less pressure needed. In my 2.35 nevegals, I started with 40 psi, and it was pretty harsh. On my last ride I dropped to 37.5 and it was perfect, rode a very rocky/rooty trail with no pinch flats, so that is where I'm going to stay. FYI, I'm 6'4" 275 naked.
    2008 Heckler

  11. #11
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    Now I see a lot of talk about pressures but no specifications for tubeless tires which are suppose to run with lower pressure. I run Specialized The Captain 2.0 on my Stumpy with 32-35 psi and work fine for me. Any toughts on tubeless tire psi anyone want to comment on??

  12. #12
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    Hey I am in South Florida and have hit up Oleta, near you.

    I have kept my pressures at 40(front)45(rear) psi on a 2.1 tire. No problems thus far, I weigh 203lbs, and do semi aggressive riding on the trails around here. Love to go off the rocks, go over them, do the few drops we have here.

    I have pinch flatted on the rear, but was running below 40psi.

  13. #13
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    Quote Originally Posted by Roswell52
    A fellow biker told me to always ride with tire pressure at 20% of your body weight.

    For the math impaired:

    150 lbs = 30lbs
    200lbs = 40lbs
    300lbs = what a clyde
    I tried this today and it felt great. I was running at 43# up front and 40# in the back but brought both tires down to 38#. The ride felt a bit softer and it seemed to improve traction. I'll probably leave them around 38# for a while.

  14. #14
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    everyone is right, but not necessarilly right for you
    for aggressive trail riding, as low as possible without pinch flatting or bottoming the rim
    for road and light trail, more pressure
    you also have to take into account your weight, type of rider (are you smooth or do you bash over and into everything?)
    also your tire size and suspension
    I weigh 220+ and ride rocky, rooty trails I generally run no less than 28 lbs, no more than 30lbs. Thats on a Fs 29er and on a Enduro , but Im looking for maximum traction and speed isnt an issue. If youre doing more fire road & road riding , I would start around 32 - 35lbs. if you find your tires slipping lower the pressure a couple of lbs. at a time. Anything higher than 35lbs isnt going to help with speed and will make the ride that much harsher
    this is a mtn. bike not a road bike

  15. #15
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    I tried 50 rear and 45 front, and it seems OK for street riding. For the trails, I'll probably drop about 3~5 PSI per tire and see how that goes.

  16. #16
    Jesus loved the dinosaurs
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    There's no mathematical "right" answer. Basically, you must take into account your weight, the tires and the terrain you ride on.

    Since you ride mostly on road with a little grass/gravel on a 1.95 tire, I'd suggest filling to the maximum volume (written on the side of the tire). It will give it less rolling resistance. You don't need the "cushion" of a softer tire because you don't ride off-road. My road bike has 23c tires (about as big around as our thumb) and I run 100lbs in them. I weigh 235lbs. On my 5" travel mountain bike, with 2.35 tires, I ride a lot of rocky, rooty terrain, so I run a much lower pressure; 35lbs in the rear, and 32lbs on the front.

  17. #17
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    For what its worth (although you've gotten great advice from some of the pros here).

    I used to run at around 35-38lbs rear tire, and 40lbs front tire. I mainly ride trails and I got tired of getting most of my flats in my rear tires. I bumped up the rear to 40lbs and I have yet to get another flat rear tire.

    Nowadays, I ride 40ish +/- on both tires.

    You just gotta give it a try and see how it goes for you until you find the setting you're comfortable with.

  18. #18
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    Feeling it out

    Am I the only guy who has no idea what pressure his tires are at? I've noticed most other riders pay close attention to what pressure they are riding but I have always just gone by "feel". I test my pressure by squeezing the tire and through trial and error have just figured out where I need to be based on where I will be riding. I've never had a pinch flat and usually get pretty good traction.

    Should I start paying closer attention to my actual pressure?

  19. #19
    Alien Surf Team
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    Quote Originally Posted by BigPerm
    Am I the only guy who has no idea what pressure his tires are at? I've noticed most other riders pay close attention to what pressure they are riding but I have always just gone by "feel". I test my pressure by squeezing the tire and through trial and error have just figured out where I need to be based on where I will be riding. I've never had a pinch flat and usually get pretty good traction.

    Should I start paying closer attention to my actual pressure?
    I do the same, but also know what pressure that tends to be. 25-30 front. 40-45 rear. If I didn't ride about a mile each way on the street to the trailhead I'd go lower on the rear.

    For beginners how the tires "roll" and feel won't be that obvious as it is to an experienced rider so a known pressure to start with is still helpful.

  20. #20
    sweet!
    Reputation: Diamondhead's Avatar
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    I'm 6'6" 245lbs I run 38psi front 44psi rear with very high volume 2.1" tires
    "It's a Sledgehamer" "Dang! You got shocks, pegs...lucky! " Napoleon Dynamite & Pedro Sanchez

  21. #21
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    Well, I hit the trails at Markham Park in Broward COunty on Saturday, and I had 40 PSI up front and 45 on the rear, and it worked out juft fine, so I think I'll keep that pressure...

  22. #22
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    Good deal, Markham is really fun stuff. I try to go there twice a month, 30 minute drive for me.

  23. #23
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    30 minutes for me too... Closer than Oleta, so I have not been there yet. I also fly RC planes, so this is a better option. Anyway, the trails were fun (I only did the intermediate and the novice for this time around; after a couple more tries I'll take a shot at the expert ones), and I do plan to return soon!

  24. #24
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    This is a bit of a change of subject but I will go anyway.
    Well i'm 5'2" 110lbs. with 2.65" tires and I ride them at about 25-30 psi so I run my tires at really low psi levels. It works great on medium jumps but I never changed them when I go on the road but i will next time.

  25. #25
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    I only adjusted my pressure after it felt wrong going up hill, felt like I would be close to pinching the rear...originally everything felt fine til I started becoming more aggressive on my climbs. The contact patch increase was very noticeable as the tread noise became much more audible which directly correlates with additional traction I was getting, but I still felt a pressure increase was in order.

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