Viewing 30 posts - 41 through 70 (of 70 total)
  • Severe pedantry
  • Premier Icon Dorset_Knob
    Subscriber

    Well how would ‘sideways traction’ be generated then?

    Premier Icon Dorset_Knob
    Subscriber

    Reminds me of the maxim that I first encountered on a Quattro owners’ forum ref driving in snow and ice:

    “4 x 0 = 0”.

    ie just cause you can go forwards on the throttle (relying on the greater mechanical traction afforded by four-wheel drive), doesn’t mean you’re going to stop on the brake (your tyres have no more grip than anyone else’s).

    Premier Icon nedrapier
    Subscriber

    eh?

    I’d say if your tyres grip enough to allow you to accelerate, they grip enough to allow you to decelerate.

    Perhaps the tyres are directional .

    Premier Icon Bez
    Subscriber

    The thing with 4WD here is that some people probably go from 2WD to 4WD and think it has more grip, which it doesn’t: it has better traction because it can deliver power through four wheels and multiple differentials, but when it comes to braking (and to a reasonable degree cornering) it works exactly the same as a 2WD car.

    In other words, you can have two cars which are identical—tyres included—except for having different drivetrains, and one will have more traction but they will both have exactly the same amount of grip.

    The point being that if you think traction and grip are the same thing, then the greater traction of 4WD is going to bite you in the arse.

    Premier Icon Dorset_Knob
    Subscriber

    I’d say if your tyres grip enough to allow you to accelerate, they grip enough to allow you to decelerate.

    The sort of mistake you only need to make in real life once to understand 🙂

    Premier Icon Mat
    Subscriber

    Surely steering and braking are still acceleration, it’s just the vector/sign are different? 😛

    The point being that if you think traction and grip are the same thing, then the greater traction of 4WD is going to bite you in the arse.

    Couldn’t the traction and grip be identical in absolute magnitude, it’s just the problem is traction control caps your acceleration to the available traction/grip whereas in the case of braking/steering the traction/grip available is insufficient to provide the required acceleration to avoid a collision…

    edit – still agree it will bite you in the arse, just questioning whether they necessarily would have different magnitudes

    hols2
    Member

    I think the thing with 4WD is that, depending on how it is implemented, it distributes the load across four tyres, so the driver is less likely to exceed the grip levels of any single tyre. If the diffs are locked, then it will prevent one wheel from locking up under braking, so it redistributes the braking load between the front and rear axles. The same applies with wheelspin through corners, so you are less likely to have one wheel exceed the available grip while the others don’t, so you can use all the available grip whereas a regular car is limited by one axle losing grip. Obviously, 4WD systems are extremely complex because a fully locked system would understeer like a pig, but the basic principle applies.

    Premier Icon Dorset_Knob
    Subscriber

    it’s just the problem is traction control caps your acceleration to the available traction/grip

    Um, cars didn’t always have traction control (millennial alert! 😉 ).

    Premier Icon 16stonepig
    Subscriber

    I’m so proud that this has descended into a good-mannered technical discussion AND a pun war. Well done team.

    mashr
    Member

    Dorset_Knob

    Member

    Well how would ‘sideways traction’ be generated then?

    Cornering (not 100% sideways of course)

    Premier Icon Bez
    Subscriber

    .

    Premier Icon nedrapier
    Subscriber

    Next time you get on your bike, try and set off sideways. You can’t:

    You can: Side hop.

    Edit:

    Bez’s edit:

    .

    Presumably he’s just remembered about sidehops and is now thinking…

    mashr
    Member

    Yet a bike with forward motion can lean over (or be steered), causing an acceleration force to be generated laterally. If traction cant go sideways then why is the circle of traction a circle?

    I’ll be honest, I’m mostly playing whilst also genuinely wondering about this as its been a loonggg time since i’ve looked at anything along these lines

    Premier Icon Mat
    Subscriber

    That’s not traction. The engineering definition of traction has been given/linked several times.

    From here:

    a physical process in which a tangential force is transmitted across an interface between two bodies through dry friction or an intervening fluid film resulting in motion, stoppage or the transmission of power.
    — Mechanical Wear Fundamentals and Testing, Raymond George Bayer

    and

    In the design of wheeled or tracked vehicles, high traction between wheel and ground is more desirable than low traction, as it allows for higher acceleration (including cornering and braking) without wheel slippage.

    I’m sorry, I’m not sure why I’m arguing this!

    Premier Icon nedrapier
    Subscriber

    goes back to the same point: a tyre does not have traction on it’s own. Traction is force delivered to move something along. A tyre can enable that force to be delivered, based on its tread, compound pressure, footprint, the surface it’s acting against and what it’s being asked to move.

    given a fat slick on grippy tarmac, the tyre’s footprint on the tarmac at any one time can be pushed agaisnt in any direction, the grip’s the same.

    The ability to apply force through the tyre by pedaling v. by sidehopping has got nothing to do with the patch of tyre in contact with the road in any instant and everything to do with the rest of the bicycle and rider that isn’t in contact with the road.

    Premier Icon nedrapier
    Subscriber

    I’m sorry, I’m not sure why I’m arguing this!

    You bloody do!

    Severe pedantry

    It’s sitting there in bold, an inch away from the box you’re typing in!

    Premier Icon Mat
    Subscriber

    😀

    Premier Icon Bez
    Subscriber

    Presumably he’s just remembered about sidehops and is now thinking…

    Mostly I was just regretting it all having gone beyond the pun stage, so figured best to just walk away out of shear boredom.

    Premier Icon nedrapier
    Subscriber

    Premier Icon kennyp
    Subscriber

    I will now step back from the podium.

    Surely you step down from a podium?

    greeny30
    Member

    At the end of the day WGAF, 16stonepig if that’s your main gripe in life then you are truly blessed, but for the 16 stone pig thing. 🐖😊.

    jamesco
    Member

    When I was young the local bus company was called Yorkshire Traction, the famous or infamous ‘Traccy buses’ which carted us to and from skule and to the saturday matinee in town, Yorkshire Grip just hasn’t got the same ring to it , that’s all

    Premier Icon Bez
    Subscriber

    Isn’t the Yorkshire Grip a technique for holding a wallet without it ever falling open? 😉

    jamesco
    Member

    Arr reyt enuff, and back to pedants corner we go…….

    Premier Icon sirromj
    Subscriber

    Our we could open the door to pedantry pantry…

    hols2
    Member

    So do unicycles have traction, but no grip then?

    Do planes on a conveyor belt have grip but no traction?

    What about a unicycle on a conveyor belt?

    Premier Icon mudfish
    Subscriber

    Oops
    Isn’t it “sheer” boredom?

    Premier Icon martinhutch
    Subscriber

    Isn’t it “sheer” boredom?

    Not on Planet Pun it isn’t. An unappreciated gem, that one.

    Premier Icon nedrapier
    Subscriber

    I liked it.

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