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I'm confused

Discussion in 'Bicycle Mechanics and Repairs' started by Archie, 6 Sep 2007.

  1. Archie

    Archie Errrr.....

    So, I fitted some Schwalbe Marathon + to my subway 8 today (go me :biggrin:).

    At the time it seemed pretty obvious: the bike's on it's back and there's an arrow saying "Drive>>>>>" to indicate which way the tyre should be fitted. Also agrees with how I think it should go.

    But now the bike is right way up the "Drive>>>>>" is upside-down and I'm thinking I got it wrong!

    It's a coin-toss I guess, but which way is right?

    Archie
     
  2. Elmer Fudd

    Elmer Fudd Miserable Old Bar Steward

    At the top of the wheel when right way up, the arrows point forwards, at the bottom they face backwards.
    The front wheel is easy to fix as you just spin it round, the back tyre needs taking off and turning.
    'twas because you had the bike upside down i think that caused the confusion
     
  3. OP
    OP
    Archie

    Archie Errrr.....

    Damn! :biggrin::biggrin:


    So, what's the difference? Will I skid the next time I take a corner in the wet?
     
  4. Elmer Fudd

    Elmer Fudd Miserable Old Bar Steward

    Not quite but "directional tyres" are cut with a certain tread pattern to disperse water only in one direction. I used to have goodyear sp1's on me old car which were directional, so the spare had to be a standard tyre that, if need be, could fit anywhere. The grip was fantastic but when you looked in the rear view mirror, anyone following you would not be able to see a thing with the amount of water you were throwing out, don't imagine you'd be doing the same speeds on a bike though ! Change 'em round Archie, winter is coming.

    Oh, and P.S. Welcome to the forum
     
  5. Smokin Joe

    Smokin Joe Legendary Member

    Tread patterns don't matter on a bike, the tyre is already narrow enough to disperse water from underneath. No tread pattern can be cut deep enough to be any use. Treads are there to reasure people who come from a car background and think they will skid in the wet without them. A slick will give better wet weather grip on a cycle tyre than a tread, so you have no need to worry about direction of rotation.
     
  6. alecstilleyedye

    alecstilleyedye nothing in moderation Staff Member

    yes i thought that, and had marks on me for quite a while to show me i was wrong. :biggrin:
     
  7. redfox

    redfox New Member

    Location:
    Bourne End, UK
    From the Sheldon Brown's article 'Bicycle Tires and Tubes'

    Tread for on-road use

    Bicycle tires for on-road use have no need of any sort of tread features; in fact, the best road tires are perfectly smooth, with no tread at all!

    Unfortunately, most people assume that a smooth tire will be slippery, so this type of tire is difficult to sell to unsophisticated cyclists. Most tire makers cater to this by putting a very fine pattern on their tires, mainly for cosmetic and marketing reasons. If you examine a section of asphalt or concrete, you'll see that the texture of the road itself is much "knobbier" than the tread features of a good quality road tire. Since the tire is flexible, even a slick tire deforms as it comes into contact with the pavement, acquiring the shape of the pavement texture, only while incontact with the road.

    People ask, "But don't slick tires get slippery on wet roads, or worse yet, wet metal features such as expansion joints, paint stripes, or railroad tracks?" The answer is, yes, they do. So do tires with tread. All tires are slippery in these conditions. Tread features make no improvement in this.
     
  8. Mister Paul

    Mister Paul Honky

    Location:
    North Somerset
    Ah, but you mixed cross-ply with radial, didn't you?
     
  9. alecstilleyedye

    alecstilleyedye nothing in moderation Staff Member

    put a rear specific tyre on the front :biggrin:
     
  10. skwerl

    skwerl New Member

    Location:
    London
    clearly didn't heed the advice of those early 70s public info adverts.

    There's an article somewhere that shows the speed required for a bike to aquaplane (and therefore need treaded tyres) is about 180 MPH
     
  11. Elmer Fudd

    Elmer Fudd Miserable Old Bar Steward

    Shite!! I need to change my slicks !!!
     
  12. Tim Bennet.

    Tim Bennet. Entirely Average Member

    Location:
    S of Kendal
    Indeed. All tread on road tyres does is to trap grit and particles of glass that then get driven through the tyre on each revolution until you puncture. A marketing gimmick at its worst.
     
  13. I've seen what were essentially slick tyres with directional markings - perhaps the plies are laid-up in the tyre carcasse directionally ?

    Even so, I can't see that mattering much with the amount of drive force you could generate through the pedals, or even with the maximum amount of braking force just before the wheel locks-up

    - if the tyre were used the wrong way round, surely it wouldn't deform ?
    (in real-world conditions, not on a lab dyno with the wheel rammed-hard against carborundum-coated brake-wheel)

    Again, marketing spiel ?
     
  14. Wobbly John

    Wobbly John Veteran

    MTB tyres' tread is generally designed to push loose material out from the centre of the tyre if you 'wheel spin' or skid, the idea being that you will 'dig' down to a more solid layer. The fact thet they also grip as they compress, and release or 'pop' the mud out to clear themselves when the pressure is released is also a feature.

    On my weird wobblebike, used for trick riding on grass and tarmac surfaces, I have the front tyre fitted against the direction of rotation, as it seems to give me more grip on grass, and less rumble on tarmac.

    Whatever way round you fit your tyre, remember, any coloured label on the tyre MUST line up with the valve hole.
     
  15. frog

    frog Guest

    That is soooooo wrong :ohmy: Tyre pressure information goes next to the valve hole. :blush: