The darkside, car tire on motorcycles

Discussion in 'The Perfect Line and Other Riding Myths' started by elkgrichard, Sep 19, 2014.

  1. anotherguy

    anotherguy Long timer

    Joined:
    Jun 18, 2009
    Oddometer:
    14,141
    Location:
    the hills
    Not sure any of those will stand up to big bike power. I do understand your point. Just adding there are reasons for using car tires.
  2. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    That seems to be the prevailing theory here: reduce air pressure, so the car tire deforms enough to provide a traction patch in a turn. Otherwise cornering on car tires would be very, very difficult. Now if the car tire deforms enough to bend the sidewall, this clearly is not something car tires are designed for, so it is vulnerable to excessive wear.
  3. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    Nobody was able to coherently articulate any other reason so far.
    ObiJohn and ontrip like this.
  4. windmill

    windmill Long timer

    Joined:
    Feb 18, 2008
    Oddometer:
    5,658
    Location:
    Kent, Washington State
    They're actually heavy duty tires for sidecar use. The Kenda is a 10 ply tire used by the Chinese Army. The Avon is popular with vintage auto folks. How's that for irony? :D
    [​IMG]
    [​IMG]
    anotherguy likes this.
  5. "None"

    "None" Make it so.

    Joined:
    May 20, 2017
    Oddometer:
    79
    Where did you read that lower air pressure is required?
    How do you know that car tire would be difficult to corner? vulnerable to excessive wear?
    Any experience to confirm your claims from operating a motorcycle with car tire mounted? or just pure speculation?

    Failure to read? I'm sure these have been mentioned before in this 130+ page thread.

    1. Better stability in straight line, highway & 2-up handling; wet or dry.

    2. Longer interval between tire change, allow more actual riding time vs bike down time; unless you prefer working on bike instead of riding.

    3. Allow more stable straight line braking performance, likely less braking distance when slamming on the brakes.
  6. CROSSBOLT

    CROSSBOLT Been here awhile

    Joined:
    Sep 4, 2018
    Oddometer:
    530
    Location:
    Hillville, TN
    I am guessing you missed my point of listing my personal experience with a closed mind at and engineering college. Let me attempt to guess what level I must aim at to convey the idea I was striving to communicate. I found the limitations of college staff engineers to be appalling. To say "everything had been invented" seemed rather dense to me. No imagination, apparently. I do, personally, understand how narrow the focus of an engineer has to be to accomplish each project. Car tires were designed, tested, re-designed and tested some more for use in cars and light trucks. The last thing on their minds were motorcycles or scooters. Just like the guys making motorcycle tires. Designing to work on, well, motorcycles. No thoughts directed at cars. Or airplanes, trailers or golf carts. This does not even address the effect of the marketing pukes who are always meddling in designs. So, what is driving the buying public to even try to put a car tire on a motorcycle? My Dad put one on his Harley (I have said this before, you missed it) in 1946 and said he would never make that mistake ever again! Handling was so bad and weird it scared him! Why did he even try? Cost. Poor wear on the rear. Same as today. He tried, the test failed. He never went back. He rode motorcycles until his passing in 2001. So what is the deal today? Cost. Poor wear on the rear. I got tired of all the work of changing tires on my scoot. Same as the GoldWing boys and others. Now WE have done the initial testing. I am waiting for the NIH (Not Invented Here) engineers at the tire companies to design and refine a steel belt radial tire for the rear of a two-wheel vehicle. But it will be very difficult to break through that thick, can't-be-done attitude (like yours) of the engineers and decision-makers to get the point that the customers want a product that ALMOST already exists even if it is for a car.
    Dirty bike likes this.
  7. glory racing

    glory racing Been here awhile

    Joined:
    Aug 23, 2013
    Oddometer:
    233
    Location:
    harrison, AR
    Lets try again...please see pic.

    The simple fact that you have to ask proves the point.

    angel gt.jpg
  8. Jarlaxle

    Jarlaxle Bregan D'Aerthe

    Joined:
    Nov 2, 2014
    Oddometer:
    12,204
    Location:
    New England
    Underinflating tires FOR THE LOAD reduces longevity. A darksided bike is loading the rear tire to, MAYBE, half its rated weight. (And probably closer to a third.)
  9. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    In about 100 posts above - do scroll up.

    Right, I forgot the straight line performance, because that's what motorcycles are all about!
    CROSSBOLT likes this.
  10. Jarlaxle

    Jarlaxle Bregan D'Aerthe

    Joined:
    Nov 2, 2014
    Oddometer:
    12,204
    Location:
    New England
    I have seen-considerably-more rollover and sidewall contact on a car that autocrossed than I have EVER seen on a darksided bike.
  11. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    I'd like to see some factual support for this assertion that "Underinflating tires FOR HALF THE LOAD does not reduce longevity".
  12. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    I didn't see any speedometer in the picture - what are you supposed to show there?
  13. Jarlaxle

    Jarlaxle Bregan D'Aerthe

    Joined:
    Nov 2, 2014
    Oddometer:
    12,204
    Location:
    New England
    Bullshit.
  14. sandsman

    sandsman Shut up and ride!!!!

    Joined:
    Jul 26, 2011
    Oddometer:
    1,356
    Location:
    Greenville, Tx
    I put my CT at 36 and have no issues cornering at all.
  15. Jarlaxle

    Jarlaxle Bregan D'Aerthe

    Joined:
    Nov 2, 2014
    Oddometer:
    12,204
    Location:
    New England
    CROSSBOLT likes this.
  16. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
  17. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    Define "no issues cornering at all". What do you ride? At what speed are you cornering? How does it compare to the feel of a motorcycle tire at the same speed?
  18. "None"

    "None" Make it so.

    Joined:
    May 20, 2017
    Oddometer:
    79
    Regardless what you forget motorcycling is about, upright or leaned;
    honestly, do the side treads on your motorcycle tires wear out quicker than the middle?
    Do you you spend more time with your bike leaned over upright?

    Here's a reminder: majority of the time, most bikes are upright; whether parked or moving. :D
    CROSSBOLT likes this.
  19. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    "Seen" as in "measured"? Do tell.
  20. liberpolly

    liberpolly Nu, shoyn, nudnick!

    Joined:
    Sep 21, 2015
    Oddometer:
    4,851
    Location:
    Seattle
    Hopefully leaned, at least the moments I enjoy and remember the most. Whether it's more or less time, it's the most important for me time.

    I am so, so very sorry.