120/60/r17 Tires

Discussion in 'Tires' started by RSXtypeS, Apr 13, 2017.


  1. RSXtypeS

    RSXtypeS Registered

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    I recently purchased a set of tires. By mistake I purchase the 120/60/r17 series instead of the 120/70/r17 series. I purchased the front and back tires online. MICHELIN tires. I have already been riding on the tires so I cannot send them back. I read the 60 series lowers the front of the bike by .50 of an inch. I like the look because I have the brocks triple tree as well. My question is this,

    What your experience with running a 60 series tire instead of a 70 series on the front.
     
  2. sixpack577

    sixpack577 Top Gun Registered

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    Smaller contact patch.
    Shorter, so less lean angle.
    If you just cruise, or only go fast in a straight line, I wouldn't be concerned.
     
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  3. c10

    c10 Registered

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    120/60/17 is common on many super sports R6 and such . You can lean as far as you care on one / drag knee / or hard parts . the 60 is the height of the tire being 60% of the width of 120 mm and a 70 series is 70% of 120 mm tall . They are both 120 mm wide = same contact patch .

    have a good read .

    http://sportbike.natkd.com/motorcycle_geometry_101.htm
     
  4. CBXRider

    CBXRider Donating Member Registered

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    Doesn't the 60 have a (larger) contact patch over a 70? Hmmmm? :)
     
  5. Bailey9r

    Bailey9r Registered

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    With same air pressure both have exact same contact patch. One is just a little squarer than the other.
     
  6. CBXRider

    CBXRider Donating Member Registered

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    I'm not buying it. The lower the number the wider the tire.
     
  7. Mikew777

    Mikew777 Registered

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    They will both have the same contact patch due to the 120 width
    If you have a 120/60/r17 vs 120/70/r17:
    120 is the width on each in mm.
    the middle number 60 vs 70 is the sidewall height. It is 60% of the width or 70% of the width.
    r is for radial
    the 17 is the rim/wheel size.

    If we do the math on the middle number for the side wall we find:
    60% of 120=72mm (120/60/r17)
    70% of 120=84mm (120/70/r17)
    these are the height of the side wall per tire.

    your contact patch for the tire is still 120 mm wide no matter how you look at it.

    overall I would rather have the tire that should be on the bike. if anything go with a wider tire not a different sidewall but if it is what you have on the bike then that is up to you.
     
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  8. sixpack577

    sixpack577 Top Gun Registered

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    Ok, same size contact patch then.
    But still can't lean a shorter tire over as far as a taller one. And shape is different.
    It's going to drag hard parts, or even the wheel lip, before the taller tire. Even if it's considered a small difference, it's still noticeable riding.
     
  9. Bailey9r

    Bailey9r Registered

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    Hey CBXer Sorry I didn't see this earlier to explain what I meant....
    120 = the width, 50 or 60 = the aspect ratio meaning 50% or 60% of the width is the height so the 60 is a bit taller than the 50 so it would seem to have more sidewall. physics dictates it takes X square inches of surface area to hold up a specific weight so they both have the exact same contact area it's just the 60 would be a bit more rectangular (front to rear) and the 50 would be a bit more square.
     
  10. michael parris heuberger

    michael parris heuberger Registered

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    Hi all. I love the 120/60/17! It lower the bike. On a ZX 11 in Fl. bikeweek 2000 my magnesium front rim split open all air out in split sec. It was on a curve at 85 MPH THE tire did not flop over it may have saved my life.I run them on all my sport bikes. I wish they would make a 120/50/17!
     

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