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  1. #1
    I eat carbide. Psimet2001's Avatar
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    Psimet's tip of the Day

    I thought I would create a place to share some of the nuggets I have gotten or given while on BF. I will come back and update this thread when I think about it. Probably no more than once a day though.



    Tip 1 - Inflate your tires before every single ride. Know what the proper inflation pressure should be for your tires. Inflation requirements will vary by rider, bike, tires, conditions, etc.

    Below you will find equations that you can use to help determine an appropriate starting point using your weight and the tire's size. Adjust from these baselines to suit needs and conditions.

    Proper inflation is the easiet way to avoid flats.

    Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
    Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
    Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
    Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33

    Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
    Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67


    Example: You are 150lbs running 28's

    Pressure (psi) = (0.33*150) +33.33 = 82.83psi (rear)
    Front Pressure = .9*Rear Pressure = .9*82.83psi = 74.55psi front


    EDIT: I added () in order to make the equations make more sense. I think some people are doing the math incorrectly.

  2. #2
    Senior Member Kimbercop's Avatar
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    My tire doesnt hold enough air, now what??

    BTW, do you accomplish ANYTHING at work, thats WORK related?? ALSO... I saw that little comment in the other post about someone descending. Might cost you a few beers this weekend for me to "forget" it.
    and the road becomes my bride
    I have stripped of all but pride
    So in her I do confide
    And she keeps me satisfied
    Gives me all I need

  3. #3
    Village Idiot
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    You have a typo, the front pressure should be multiplied by rear pressure not by front pressure

    This should be a fun thread.
    Truth, like light, blinds. Falsehood, on the contrary, is a beautiful twilight that enhances every object.
    -Albert Camus

    Hammer Nutrition 15% discount!!!

  4. #4
    grilled cheesus aham23's Avatar
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    first i need the freaking tip on how to tell what tire size i have?!@? geesh.

    later.

  5. #5
    bannned steaktaco's Avatar
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    Quote Originally Posted by Psimet2001 View Post
    Front Pressure = .9*Front Pressure = .9*82.83psi = 74.55psi front
    Can't... get it... to work.

    Head hurts. Is it like the sound of one hand clapping?
    steaktaco.com <-- poohoopsies.


  6. #6
    Senior Member Talewinds's Avatar
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    Quote Originally Posted by Kimbercop View Post
    My tire doesnt hold enough air, now what??

    BTW, do you accomplish ANYTHING at work, thats WORK related?? ALSO... I saw that little comment in the other post about someone descending. Might cost you a few beers this weekend for me to "forget" it.
    Are you sure he works? I just thought everybody posting here during the day didn't work, like me...

  7. #7
    You Know!? For Kids! jsharr's Avatar
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    Psimet works at UselessBikeTriviata Inc., a subsidiary of PCadhatesyou Worldwide Holdings Ltd.
    Are you a registered member? Why not? Click here to register. It's free and only takes 27 seconds! Help out the forums, abide by our community guidelines.
    Quote Originally Posted by colorider View Post
    Phobias are for irrational fears. Fear of junk ripping badgers is perfectly rational. Those things are nasty.

  8. #8
    cmh
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    I come in at 109 rear, 98 front. That is about what I use on wet, relatively smooth roads in a race. Seems a little low to me for dry conditions. On bad pavement I'd be risking a pinch flat.

  9. #9
    Senior Member 04jtb's Avatar
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    I come out at 99.8psi for my 23s

    i think that is a bit low really - according to my gauge on my pump (probably wrong) I put 120psi in often
    Quote Originally Posted by cc700 View Post
    i jam my thumbs up and back into the tubes. this way i can point my fingers straight out in front to split the wind and attain an even more aero profile, and the usual fixed gear - zen - connectedness feeling through the drivetrain is multiplied ten fold because my thumbs become one with the tubing.
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  10. #10
    NYC Maggie Backstedt fan
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    Now I have to carry a scale as well as a pump in my bike kit?

    No need to reduce tire pressure while riding to compensate for fluid loss; your tires will do it for you.

    With a little practice, of course, one should be able to do these calculations in one's head.
    "I can't believe we still have to protest this crap." - courtesy, Johnny Monkey

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  11. #11
    your nightmare gal chipcom's Avatar
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    Holy crap, I did the math, but the answer I got was
    "Pump your tire up as much as you can you fat b@stard. If the tire blows, stop the lesson."
    "Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey

  12. #12
    175mm crank of love RichinPeoria's Avatar
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    Thanks, I havent seen this before.

    Ive been trying to dial in my pressures during my last few rides few rides.

    Ill try the front pressure=0.9Xrear pressure tonight.
    Have a good day and htfu you big baby, Rich
    Quote Originally Posted by coasting View Post
    So I step away from BF for a day and this thread takes a nose dive! .....
    The only good bit is RichPeoria's yummy food pics again! Congratulations Rich; you are a king amongst fools

  13. #13
    Senior Member huytheskigod's Avatar
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    Quote Originally Posted by Psimet2001 View Post
    Front Pressure = .9*Front Pressure = .9*82.83psi = 74.55psi front [/COLOR][/I]
    Infinite Loop!!....ERROR...Core Dump

  14. #14
    How much does it weigh? prendrefeu's Avatar
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    Psimet, it doesn't matter how many excuses you want to come up with (tire pressure being one of them), you'll still get dropped and we'll still yell at you.

    That is all.
    Weight weenies keep it light.

    Director of the Midnight Express Ride; Board of Directors, Los Angeles County Bicycle Coalition.

  15. #15
    I eat carbide. Psimet2001's Avatar
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    I fixed the infinite loop

    Yes...I do work...although we did block access to Bikeforums on our firewall here....wonder why.

    Not to worry. BF nerds helped me supply my addiction.

    I do not currently - nor do I have plans to - work for pcad or any of his subsidiaries. I should though because then maybe I could afford some Zipps...even if they were used and from ebay.

    I will forever remain ....off the back...

    Kimbercop - You know I was joking *as I reach for my wallet and hail the waitress*

  16. #16
    3 seconds ColorChange's Avatar
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    This is funny PSI.

    My WalMart tires on my schwinn commuter only go to 100psi. I'm in trouble.

  17. #17
    . botto's Avatar
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    I never did calculus in HS, but thanks.

  18. #18
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    Lets make more jokes about how stupid we are.

  19. #19
    Up on the Down Side CyLowe97's Avatar
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    The tires on my Radio Flyer three wheeler don't seem to have a place to put air in them.

    What now, genius?

  20. #20
    superArti artifice's Avatar
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    so, 89.6 rear, 80.64 front? that seems seriously... low.

  21. #21
    bannned steaktaco's Avatar
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    Maybe these values are for charity rides...
    steaktaco.com <-- poohoopsies.


  22. #22
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    Ya those numbers seem low. Here's a useful tip: The easiest way to prevent flats is to buy a pair of Specialized Armadillo tires. Unless you run over a razor blade or an industrial sized nail, you will not get a flat, and they last for ever.

  23. #23
    your nightmare gal chipcom's Avatar
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    yeah, everyone knows armadillos will prevent pinch flats.
    "Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey

  24. #24
    Knowing's half the battle SushiJoe's Avatar
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    Quote Originally Posted by jsharr View Post
    Psimet works at UselessBikeTriviata Inc., a subsidiary of PCadhatesyou Worldwide Holdings Ltd.
    Are those publicly traded companies?

  25. #25
    I eat carbide. Psimet2001's Avatar
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    - *shakes head* - most riders ride with their tires pumped way too high. Seems they all decided to post today.

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