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What brakes quicker... big bike or scooter??

Discussion in 'Bike Reviews, Questions and Suggestions' at netrider.net.au started by Lectre, Sep 14, 2007.

  1. hey all.
    A mate of mine and myself had a disagreement on what would pull up quicker, my bike (an SV1000n, or similar) or a generic scooter (we were comparing to his "bug")?
    I was thinking that even though myself + bike weighs in at 275-ish kg (yes I'm very light), I still have twin discs up front with big wheels (diameter, and contact surface area due to weight) would have the advantage, but his thoughts were that the weight difference alone would make ANY scooter pull up quicker...
    What I'm thinking is "Full" (IE emergency) braking, but we agreed 60km/h + speeds would only make the comparison relative.
    Any thoughts out there? Does anyone regularly go between a scooter and a bike?
    Would love to point this thread to him on monday regardless of outcome :)


     
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  2. i beat scooter any time any day. the only time i lost was when i decided to let him go
     
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  3. Whichever one's got the better tyres, really. Even a single disc with twin-pot caliper can lock up a front wheel. Weight on a scoot is further backward, making it less likely to stoppie, which is an advantage for the scoot. I wouldn't think the weight difference would be such a huge factor.

    Incidentally I was riding an electric maxi scooter for a road test today, that thing stopped on a dime.
     
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  4. I think quality of suspension would play a part (ensuring that the tyre is always on the road). Also the width and quality of the rubber would have to be accounted for. I'm no physicist but I think weight would work both ways in the stopping equation. Weight once moving turns into momentum, more momentum means harder to stop. But more weight means more downwards force to ensure a good contact patch between rubber and road. I'd but $5 on a well setup sports bike (SV included).

    Other factors I would think are important are, what is the road surface like (bumpy, corrugated)? Are you braking in a straight line and not turning or loading the suspension in any other way? How difficult are scooters to brake at maximum capacity compared to bikes?
     
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  5. Mostly going to come down to tyre contact area - this is why many cars can brake as well or better than the best sportsbikes despite the massive difference in weight.
    For a given width a smaller diameter wheel is going to have significantly less contact area - so I'd be putting my money on the bike.
     
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  6. apples and oranges...
     
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  7. Obviously. :roll:

    The question is does the apple or orange stop quicker.
     
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  8. weight low and to the rear? yeah scoot wouldnt stoppie, it'll just friggen skid :roll:
    it wouldnt be bike or scooter as a rule. it would depend on many things, kerb weight, weight distrubution, tyre size and compound, diameter of discs, suspension, lots of things. my missus is buying a bug espresso this weekend, nice big wheels. so ill throw on my one piece suit, take the scoot up the old pac and get back to you :LOL:
     
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  9. Scooters certainly do stoppies. :cool:
     
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  10. i get that, but there simply is no answer to this question :roll:
    there are far too many variables to determine a definitive (correct) answer ;)
     
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  11. A perfectly tuned car would, they can't control their bias, where-as we can. ABS not included, a car will usually lock the back up fairly quickly when the foot is jammed down, and then the front locks up not too soon after causing the car to skid.

    At least with a bike we have control over whats braking at what time, further into the brake that you are the more front you use.

    Average bike rider i reckon could pull up faster then the average car driver.

    Between bikes and scooters i would say bikes only because the average scooter has smaller wheels, smaller brakes, usually cheaper tyres and worse suspension and the weight is at the back as opposed to the front (where the majority of braking occurs). But it would all depend on the rider of both.
     
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  12. On a dry road, ANY half decent rider on a scooter OR a bike, with half decent tyres and brakes, is going to be limited to braking power by ONE THING

    STOPPIES.

    An english mag, I think it was MCN, did a test about 2 years ago, and

    The quickest stopping bike in the world from 60mph is the HONDA VALKYRIE

    It even stops better than a MotoGP bike.

    Why?

    Because it can't do stoppies,
    it's too long, low, and heavy. And the tyres and brakes are adequate.

    Of course, this assumes equal rider skill, and depends on how far back on the bike the rider can sit, etc etc.
     
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  13. Why dont oyu and your mate find an open unused road somewhere and test them out. That way you will really know.
     
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  14. Serious?? I've only seen them lock up, in rather speckie fashion too :LOL:
     
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  15. lets list the variables.
    given information -
    same road, same time, same temperature, same rider. This conrols quite a few with regard to reaction time, weight, surface etc.

    variables -
    wheel size
    1)braking capacity changes with the diameter of the wheel. the force required to decelerate the wheel to zero, which is applied via braking, becomes greater as wheel diameter gets smaller by a calculation of simple levers.
    2)however, this is countered by the momentum of the wheel to continue spinning against the braking force - larger wheel = heavier = f=ma = bigger wheel takes more force to stop.
    3)width; a wider wheel has a larger contact patch, therefore it is able to whitstand a greater coefficient of friction before it breaks traction.

    how much does point 1 effect point 2? that requires some serious crunching of numbers. how relative is contact patch area? well, as tyre width increases, the force required to break traction increases exponentially. so we deduce that a greater contact patch is going to offer a better ability to brake.

    Weight Distribution
    as pointed out earlier, a two wheeled vehicle is limited in its ability to stop by its tendency to "stoppie". so we can assume that a bike configured with weight more towards the rear would have a greater ability to whitstand performing a "stoppie". The effect of the weight distribution is amplified by the length that the weight (or force via gravity) is located from the fulcrum (or front wheel; pivot point) so a longer vehicle, with weight shifted rearwards will be much less likely to "stoppie" than a shorter, weight-forward vehicle.

    Braking Apparatus
    disc, twin disc, drum, buell disc - all require different amounts of pressure applied to stop your bike. refer to point 1 in wheel size with regard to the braking capacity of a larger disc compared to a smaller disc.
    compound in braking pads; this is all about the friction modifiers in the actual pads used in your brakes. the create friction upon a surface to slow/stop movement. pads with a higher coefficient of friction will stop you quicker.
    disc composition; slotted, drilled, wave, etc. this is about surface area. more surface for the pads to work on the better they will work....however, more surface = more heat generated = less braking efficiency (but thats another thread all together.

    i can keep dribbling shit, but you get the idea, right? you can compare a bike with a scooter. but you cant generalize, well at least i dont think you can.
    having said that, my money would be on a bike ;)
     
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  16. Dunno what you've been driving (or how you've been driving it ;)) but I've never had a car lock the rear brakes before the front (unless I was using the handbrake). And just as unskilled drivers can lock the front so too could an unskilled rider so I don't really see where you were going with that. :?
    Of course these days you're going to be hard pressed to find a car without ABS anyway but even older cars (for example the original Mini) had systems which would actually reduce, or completely eliminate, rear brake pressure under hard braking - and a lot of other cars simply had crap drum rears which did the same thing anyway ;).
    It's dangerous to assume a bike can outbrake a car, when the reality is very different (plenty of roadtests both for cars and bikes which quote stopping distance from 100kph). Against something as simple as say a Volvo S70 with ABS even a good rider wouldn't stand a chance - even worse if you're going faster than them to begin with.
     
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  17. I think that has more to do with rider technique than vehicle design though.
     
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  18. A land cruiser can outbrake a lotus elise. Can't remember where I read this, but it's because the land cruiser has fatter tyres.

    Point is, weight is not a major factor in braking distances. Weight distribution is however important.
     
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  19. Hrrrm my basic googling has me doubting those claims:
    60-0 for Lotus 114ft
    60-0 for Land Cruiser 135ft

    Yep, hardly a back to back in same conditions comparison. But I call BS on that one.
     
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  20. I may have been thinking of a land rover? Honestly, I wouldn't remember.

    As the first link I checked shows http://www.movit.de/rahmen/stoptbl.htm, under conditions of "100 kmh - 0 cold & empty" (whatever that means), a landrover freelander can outbrake an elise.

    Lotus Elise 111s- 44.3 (metres I assume?)
    Landrover Freelander 2.0- 43.8

    Point is, clearly factors other than weight are more important.
     
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