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Bike weights

Discussion in 'Bike Reviews, Questions and Suggestions' started by enuenu, Mar 18, 2009.

  1. Why for example, does a Hyabusa (260kg curb mass) weigh 88kg more than a GXS-R1000 (172kg curb mass)? Why does a ZX-14 (215 kg dry) weigh 36kg more than a ZX-10R (179 kg dry)?

    I realize a manufacturer's supersports race models will always be lighter than the supersports tourers. I just would love to see a powewrful sports tourer sub 200kg. Maybe this is too light for long distance touring?

    I would have thought that a ZX-14 that weighed just a bit more than a ZX-10R or a Hyabusa that weighed just a bit more than a GSX-R1000 would be great. Surely a Busa doesn't have to weigh 260kg.

    Why don't they make the Busa and ZX-14 lighter? Basically a more comfortable GSX-R1000 or ZX-10R with a broader power spread. Would dropping 30 or 40kg (or 60kg for the Busa) make the "non-race" versions less able tourers? Are they made heavier deliberately to make them more stable, more resistant to wind gusts etc and easier to ride longer distances? Maybe the weight is due to extra components it needs and they can't get any more kg off it?

    My knowledge on the effects of weight is obviously limited. I just would have thought lighter is better, but I guess there is a limit to this.

    The Hyabusa weighing 45kg more than the ZX-14 is also surprising. The Busa is a real tank it seems. Suzuki quotes curb mass and Kawasaki the dry weight, maybe this accounts for some of the difference but in any case it is still a big difference.

  2. You're way too nice Morbo. :?
  3. You do wonder where the weight is sometimes. It's pretty easy to account for 10 or 20kg through heavier and extra parts, but after that you scratch your head.

    a lot of it comes down to the engines they use. Despite claims to the contrary these bigger bikes tend to use engines based largely on older designs. Older style engines were built more robust. Time and technology has allowed engines to get more compact and carry less unnecessary material.

    If the engine is heavier and the engine torquier then the chassis must also be heavier. and the suspension components must be more robust.

    So it's not just the difference between alloy and magnesium covers. it's the addition of a lot of little things

    I still do wonder where the weight is sometimes
  4. I wanted to get in before you yelled at him, Dougz :p :LOL:
  5. Cheers. I've got a thick skin so fire up! I just edited my first post a little. The Busa seems especially heavy. Is 260kg a misprint on the Suzuki Website? That puts it a lot heavier than its Kawasaki competitor.

    Maybe the older heavier motors last longer and have lower running costs? However would Busa owners say no to a 60kg weight drop?

    Like I said a 190kg Busa with a GXS-R1000 motor that has had its midrange fattened would be a great bike for the open road I reckon. But I know f%&* all really.
  6. First, let's get some correct figures established. Actual curb fully fuelled mass of the various litre bikes (according to AMCN) are:

    '08 Ducati 1098S => 202kg
    '08 Honda CBR1000RR => 202kg
    '08 Kawasaki ZX10R => 211kg
    '08 KTM RC8 => 206kg
    '08 MV Agusta 312R => 222kg
    '08 Suzuki GSX-R1000 => 213kg
    '08 Yamaha YZF-R1 => 212kg

    Ok, so having established that, you can now make your comparisons.
  7. Well, 120kg dry. It's a liquid cooled bike, so after putting the battery in, the coolant in, engine oil, fork oil, brake fluid, and air back into the tyres, you're probably talking around 130kg with an empty tank. With a 10.5L tank, you're looking at around 8kgs of fuel, so all up, around a 138kg fully fueled wet curb weight.
  8. You won't get much bore into a modern motor. Most of the capacity increase would have to come from stroke, but of course that doesn't yield capacity as readilty.

    So if it were based on the 1000cc engine you'd likely only get 1100-1150cc. At least that would be what the factory would be willing to do. After market would be a different story.

    So an 1150cc bus that weighed 60kg less? I can see merit in that. But I did own a gsx-r1100
  9. An interesting comparison is the 675 Street Triple vs the Daytona 675. Same frame. Same motor. Same wheels. The Street Triple has no fairing yet is 4kgs heavier, and you scratch your head wondering how that can be. Look closely at the two bikes, and where they've used machined aluminium on the Daytona in various places, they'll use cast mild steel instead on the Street Triple. Many of the bits and pieces that are bolted onto the bike are made out of heavier and cheaper (but stronger) steel.

    Sports bikes commonly used for racing are made to be light, especially since not only what wins on Sunday sells on Monday, but also because of various Superstock rules which allow minimum modications, and magazines doing things like off-the-showroom-floor track comprison tests. Whereas before manufacturers used to just bolt bikes together, if you look at a number of modern sports bikes (especially Honda's) you'll find that they're actually using bolts that are core-drilled to save weight. Some of the heavier bolts can weigh 100g or even more. Core-drill the twenty or so of those found on most bikes to save half the weight, and bingo, there's a 1kg weight savings with the bike not looking physically any different. Multiply that by the hundreds of bolts holding bikes together, and it adds up fairly quick.
  10. Point taken. However it is the relative weights within a manufacturer's range that are telling as I assume they adopt the same policy across the range when determining what weight they will post on the spec sheets.

    Thus the Hyabusa being 88kg heavier than the GSX-R1000 is a valid comparison and the same goes for the ZX-14 being 36kg heavier than the ZX-10R.

    Could you see a disadvantage to the Hyabusa weighing 230kg fully fuelled and lubed?
  11. A distressing tendency to travel sideways or become airborne at speeds in excess of 300 km/h? :grin:

    Seriously though, have a look at some accounts of the antics of the very first GSXR750s back in the 80s for an example of what can happen if you build a fast bike too light. Unlike pretty much any other sports bike I can think of, the little GSXR gained weight for several generations in a tacit admission by Suzuki that they didn't put enough meat into it to start with.
  12. have you had your license yet?
  13. Not quite true. Manufacturers will switch between stating "dry weight" for their sports bikes, if only because they like to give the indication of how light their bikes are in such a competitive arena even though the stated value is highly misleading.

    For bikes that aren't race-bikes with lights, they're less concerned about that, and can and do state half-wet weights (all fluids except fuel) or even curb weights (all fluids plus a full tank).

    The Suzuki stated dry-weight for an '09 Hayabusa is 220kgs. Their curb full-wet weight is 260kgs, or 47kgs heavier than their GSX-R1000. 3kg of that extra weight is from the larger fuel capacity. So basically we'd talking about the 'Busa weighing 44kgs more than a GSX-R 1000.

    I'd hazard a good guess that with the larger engine, it also requires a bigger battery to turn the motor over (+1kg), more oil (+1kg), and more coolant (+1kg). The engine is physically larger and puts out more torque. That means more metal in the casing, more metal in the conrods, more metal in the pistons, bearings, gears, gearshafts, valves, exhaust headers, exhaust pipe diameter, injector rails, etc, etc. The starter motor is going to be heavier, as is the clutch that goes with it. The alternator is also going to be of a higher capacity 'cos it's a sports-tourer, and that adds weight. So, we've added all this weight to the motor to deal with the larger capacity and higher torque, which now means the frame has to be beefed up to carry it. Everything has to be made thicker and stronger, including even the rims, the forks, the brake carriers, the brake discs, and so on.

    Would not surprise me in the slightest if there's a good 30kg of all the extra weight accounted in all of that. The extra 10-15kgs likely comes from using steel instead of aluminium in various places, the larger, heavier, and more aero-dynamic fairing, and various sport-tourer creature comforts.

    Suzuki could maybe lop 20-25kgs off the 'Busa if they were going out of their way to develop a large capacity pure sports bike, but that's not what the 'Busa is.

    They'd maybe get it to 235-240kg fully fueled, but not much less than that, by turning it into something which it wasn't originally designed to be.

    Nothing stopping you from taking a knife to it though...
  14. Yep, that's about right :wink:
  15. hmm i was beaten to it but that idea of a 178keg curbside weight for a gixxer thou seemed just ever so slightly optimistic.

    i dont think however you would want a bike that big to be that light either. im guessing that since it isnt a sports bike, some of that weight goes into making longer service intervals / better reliability. thats what you want a sports tourer for isnt it? a bit of fun and longer trips without having to service it every second ride.
  16. Also take into account the targeted riders, a gixxer 1000 is designed for a jockey where as a busa is aimed at joe average + his pillion.

    Who of the two riders needs the bigger horse under them