tire pressure

Discussion in 'Wheels' started by longshot, Jul 12, 2011.

  1. longshot

    longshot New Member

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    If i mess up somehow, be patient, this is my first forum. I ride an 04 Deuce with HD Dunlop tires. The Harley owners manual shows 30 psi for HD Dunlop front tires. The tire itself shows 40 psi cold. That's a pretty large difference. Anyone know which pressure is the right one? Thanks!
     
  2. cdn-bigfoot

    cdn-bigfoot Junior Member

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    I always default to the recommended psi stamped on the tire. HD uses several different brands and styles of tires. One pressure for all of those can't be right. The tire manufacturer knows their tire best.

    And welcome to HDTalking!
     
  3. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    I suggest that folks go to the tire manufacturers website and get the recommended pressure for the actual tire brand and model for the bike. So for Dunlop tires, that would be here:

    Fitment Guide for Dunlop Motorcycle Tires (enter HD, and the bike model/year)

    However, if you are not running the recommended tire, you will have to that manufacturer's website.

    TQ
     
  4. BOWHIKER

    BOWHIKER Junior Member

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    That's strange because my manual says 30 psi fot the front , dunlop say 30 psi also but the dealer told me 32-34 psi . I wonder why that is .
     
  5. dbinbc

    dbinbc Active Member

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    On my '09 EGC, I switched from the stock 407 (rear) to an American Elite. Manual said 40, new tire sidewall said 42. I Emailed Dunlop and they told me to go with what my manual said, not what was on the side wall. May have something to do with what the rims are designed for but not sure about that.
     
  6. AZRobert

    AZRobert Member

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    Read tire sidewall carefully - it should say MAX (maximum) pressure is XX psi - not recommended pressure.

    Recommended pressure is in your manual - it is for the recommended size of tire - not brand.

    Pretty much all passenger tires (not LT or truck tires) have the same sidewall composition - namely 2 Ply.

    The recommended pressure allows for the "Flex" of this size tire at a certin pressure. This amount of "flex" is engineered into the suspension geometry (along with shock absorbers and suspension bushings). If you change tire size, this may alter suggested pressure recommendation. But if you use the same recommended size, the pressure for that model vehicle (car or motorcycle) should remain the same as the vehicle recommended.

    Sometimes different pressures are recommended for different loads - motorcycles when riding 2 up, Trucks when loaded or towing, and my BMW had different pressures when carrying passengers in the back seat.
     
  7. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    In the Dunlop motorcycle tire information found on the website at the link below, they make this statement:

    "For high-speed, fully loaded or dual-riding touring-motorcycle applications,
    inflate tires to maximum recommended by vehicle manufacturer for
    Dunlop fitment. Never exceed maximum load indicated on tire sidewall or
    vehicle capacity load found in owner’s manual, whichever is lower."

    http://www.dunlopmotorcycle.com/pdf/11D_FL_SAFETY.pdf

    So the information on the sidewall is actually a load rating at what the tire manufacturer considers the maximum tire inflation pressure for that tire. It is a load rating that is being stressed, not a recommended tire inflation pressure. However, if the bike is going to be run at high speed, with maximum rated load, then that tire inflation level would be recommended. It is up to the rider to make sure that the tire is not being overloaded based on all the weight that is on the tires.

    TQ
     
    Last edited: Jul 14, 2011
  8. deucedog

    deucedog Active Member

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    Also note that most tires will say that 'at maximum load' to use the maximum pressure.
    The Metzler rear tire on my bike says to use 50 psi (cold) at maximum load rating (937 lbs).
    I run mine at 42 lbs, as suggested by both Metz and the Indie that I bought the tire from.

    Using the higher pressure will result in better tire mileage, but in a harsher ride.
     
  9. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    The sidewall marking is the max. cold rating and would generally be too HIGH unless you are running the bike AND tire fully laden with passenger and full luggage. As has been said earlier, the H-D label on the front frame downtube is a good start...30 PSI Front and 40 PSI Rear for the stock H-D wheels and tires (Dunlop).

    Going up 2 lbs up in the rear is what I run, this is from the wear pattern of the previous tires which was even...which indicates to me that my inflation pressure was okay. If the edges were worn much more than the center, underinflation or seriously lots of leaning and cornering; if worn in center only, overinflation or lots of straight up "type" of riding and loading.
     
  10. longshot

    longshot New Member

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    Thanks for the welcome and the info. Learn something new everyday!!