Optimal Tire Pressure for High Speed Riding

Discussion in 'Motorized Bicycle General Discussion' started by Motorbikenewb, Nov 24, 2013.

  1. Motorbikenewb

    Motorbikenewb New Member

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    Greetings Motorbicyclists,

    Quick question. Car tires have a pressure/max speed rating on the side of the tire, stating the limit of how fast you should drive with that tire on the highway.

    Bike tires don't have such ratings, instead we go by the recommended inflation pressure for the tire (usually between 45 - 60 PSI). Give that, what would be the optimal tire pressure for a Cruiser motorbicycle at 30 mph assuming a rider weight of 200 lbs?

    I'm asking in order to reduce the risk of a blowout while hauling ass :)

    .wee.
     
  2. bairdco

    bairdco a guy who makes cool bikes

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    most cheap cruiser tires are rated at 30-35. they'll handle 30mph all day long at that pressure.

    better tires rated for higher inflation can be pumped up to whatever's comfortable for you.

    bikes are a low weight vehicle. the tires don't heat up like cars or mc's. they can also add a bit of suspension. i never run mine over 40 on the street. city streets are cracked and bumpy. running tires at full pressure gives a harsh ride.
     
  3. 2door

    2door Moderator
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    Don't exceed what it says on the side of the tire. If 40 is the max, don't go over 40psi.
    Over inflating the tire above the manufacturer's recommendations is not wise or safe. If mine says, 45 max inflation I keep them at 40. That's a 5 psi margin for gauge error and hot pavement. Treat you bike tires like you would your car tires. You wouldn't over inflate them. Same principle.

    Tom
     
  4. Mike B

    Mike B New Member

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    Every bike tire I ever had had a max inflation rating clearly molded into the side rubber.

    Did you sand them off curb sliding?
     
  5. Motorbikenewb

    Motorbikenewb New Member

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    Yes, that is true... it does have the max pressure rating on the side, but nothing about max speed. That's what I was trying to get at with this post. I normally inflate all my bike tires to the recommended PSI when biking (when I'm pedalling), as I can get more miles per effort.

    With the engine power, softer tires will hurt fuel economy but if it means a safer and more comfy ride, its worth it.

    brnot
     
  6. dodge dude94

    dodge dude94 New Member

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    I run mine at 65.






    :D


    *hides behind sofa*
     
  7. maniac57

    maniac57 Old, Fat, and still faster than you

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    I usually run slightly under the max to soften the ride a bit. Too much soft make the bike feel squirmy though, so don't go too soft.
     
  8. Dave31

    Dave31 Moderator
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    Used to take a tire pyrometer to the races. I never even saw 1* in temp rise on any bicycle tire that I tested. Did not matter if it was 2 laps or 20 laps never saw a change in temperature.
     
  9. Nashville Kat

    Nashville Kat Active Member

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    After racing for so long- I usually tend to feel the recomendations on larger tires especially are sort of a joke-

    there's just so much friggin rubber there.

    I'm thankful i'm not racing around on sew-ups bombed up to 100 psi or so- because that indeed was and is a tenuous situation-

    but anything clincher- unless made really poorly can handle 75 as far as I'm concerned-

    and the only thing I like at all about larger tires- beyond a higher profile to save heavier rims from damage- is the fact that they don't blow out as fast and then still have all sorts of rubber over the rim to get slowed down and stopped

    a sew-up tire would go up like a firecracker and big trouble on a front rim in a corner or on a descent- a 700C clincher of anykind has a lot more margin of error even in a blown out situation-

    a flat on a cruiser rim is just a pain in the ass, but I guess could be a problem in a corner if you don't notice it going flat.
     
  10. rogergendron1

    rogergendron1 New Member

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    idk man just pump it to the max the TIRE SAYS !

    i have tires that say 30lbs max and hookworm clone tires that say 60lbs ! it all depends on your tire and tread !
     
  11. rogergendron1

    rogergendron1 New Member

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    lol i have had tires blow in my face at 40 lbs ! the ones i run now i pump to 60 but seem like they could take a bit more like 70lbs or so
     
  12. bairdco

    bairdco a guy who makes cool bikes

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    i wouldn't go passed the max on any tire. i figure the tire manufacturere knows more than me.

    dave went all out with a pyrometer so that should be proof enough.

    wouldn't say the same for hubs, though. the street bike i had that would do over 50 would boil spit off the shimano coaster hub after some long top speed runs.
     
  13. 2door

    2door Moderator
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    Why would anyone exceed the tire manufacturer's max pressure rating? That's an accident waiting to happen no matter the vehicle, car, truck, motorcycle or motorized bicycle. And it can happen on the vehicle, or in your face.
    I've never seen a pneumatic tire that didn't have a pressure rating moulded into the sidewall. They're not always obvious, but they're there. Heed them.

    Tom
     
  14. Nashville Kat

    Nashville Kat Active Member

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    Because they're just stupid numbers fostered upon us by yet another part of the larger corporate conglomerate all run by BIG OIL-

    it's a bunch of B.S. by upper management anai who WANT you to struggle pedalling some outdated WWII heavy piece of poo with heavy spongy tires on it-

    so you'll beef up that motor as much as you can
    buying more fossil fuel for it
    and say "I NEVER want to pedal that heavy thing"

    and you'll work on everone's gas guzzlling car or truck or stupid noisy chopper for a living
     
  15. 2door

    2door Moderator
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    Obviously you've never seen a tire explode and take a man's lower face off. I did.
    But you go ahead, ignore the max pressure rating and inflate to whatever you choose.
    That's your prerogative. Just don't tell others that it is okay to do here. We like to see our members take safety seriously.

    Tom
     
  16. dodge dude94

    dodge dude94 New Member

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    You keep thinking that, Nashville. And don't come crying to us when you're riding down the road and your tire explodes, sending you into a truck.
     
  17. Danschutz

    Danschutz New Member

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    When I was 17 I pulled a tire out of my car, it had 8lbs of air in it. Placed it against the wall in the garage and crawled under my car to pull the tranny (smoked it from a night of racing) and then BANG! That tire blew the sidewall apart, man that was an eye opener. The tire was nearly flat.

    As for bike tires it depends on the tire and the weight the tire needs holds up and what your doing. I'm a light weight at 165 and will run my tires at max or 5 lbs under max if we are going out for some fun riding, if we are out to just cruise I drop them to about 5 lbs above minimum.

    At max pressure the stiff chassis of my bike beats me to death after 40 minutes lol.

    Dan.
     
  18. Nashville Kat

    Nashville Kat Active Member

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    I've seen a man burn to death in front of me at Indianapolis.
    I've seen the emergence of 50 and 70 car pile-ups, and mostly the past two years.

    I've seen cycling suffer from a strange part incompatibility for a lifetime, while the better transportation bikes of 40 years ago have been pushed out the exotic or the terribly mundane and stupidly clunky-

    but I have no problem riding clinchers with 75 pounds of pressure

    never have and never will-

    if an accident happens to me- it's because it's an accident

    not because a corporate world would just as well see everyone with cement wheels if they could sell them to us

    I raced USCF for 14 seasons and mostly as a Category 1- when all we had were sew ups

    spare me your horror stories -
    I know tire failures based on millions of miles of my own and the riders around me.

    No one wants to fall LESS than I do, and no one takes more care moment to moment

    on the other hand, I am tired of internet "expertise"

    of greater danger at this time is a growing road rage among motorists and largely spurred by internet chat boards- chat boards full of "experts"

    take your advise there- I am not listening. I've spent a lifetime around bikes, and still amazed that I'll see some freak on a sport motor bike go weaving through traffic on a freeway at 90, and no one has anything to say

    but when it comes to riding a thinner or higher pressure bike tires, the lay American public suddenly is all sooooo "safety conscious".

    I still think you've been sold FAT TIRES by oil company corporate policies for years and years. Jeez, they even have a more filling, poor tasting beer by that name now

    If you want that tiny motor to push a bunch of weight that doesn't roll well on heavy spongy tires, then go ahead. If you think it's vital, then good for you. A Motorized can be lighter and better pedalling than a moped.

    But you've kept some simplicity and ease out of this game, the way the manufacturers have intended, and intended with other concerns, overiding any they might have to your own safety. You may also think then they have liberties to play with your heath and well being to evoke your servitude- but personally I've had some glimpses into that that you wouldn't want to see and they certainly wouldn't want me to share with you. CORPORATE has a higher agenda and bikes, and motorized bikes don't rate very high on it- I don't think their psi recomendations are sacred myself.

    More likely prescribed by a Sarah Palin,
    All I'm sayin.

    maybe next Thanksgiving then, cause you made it through this one alive.
     
    #18 Nashville Kat, Nov 29, 2013
    Last edited: Nov 29, 2013
  19. Danschutz

    Danschutz New Member

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    Nashville Kat

    I don't doubt your expertise in this matter, heck the great thing about Merica is every one is entitled to their own opinion. Heck I know a guy that swears seatbelts kill more people than they save.

    With your vast experience Im sure you know all the ins and outs of the race scene "been there done that" you know how important maintenance is and what to look for, you know what feels like a bad near out of control wobble is and not just cracks in the pavement. Point is some fellows might read your post and disregard the important stuff and just read inflate to your wildest whim. In the mind of some out there that could lead to a dangerous situation.
     
  20. Moto

    Moto Member

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    well in my higher spped bikes I run 45-50 psi in a tire which is rated for 60. On my mountain bike (non motor) I run 40-50. On my cyclocross bike I run 55-65psi. On my beater motor bike I pump up the tires to 30ish psi and then pump them up again when the bike bottoms out :p
     

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