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Interesting concept from ARR Magazine...

Discussion in 'Technical and Troubleshooting Torque' started by pete the freak, Dec 14, 2006.

  1. So was reading the latest "Australian Road Rider" magazine the other night and came across an article where they gave a bunch of girlys HDs to ride for the day.

    They quoted the rep from HD as saying that because HD (and cruisers generally) have a much lower CoG than sports bikes, they don't actually have to lean as much to achieve the cornering. So he was basically saying, sure cruisers can't lean as far, but they don't have to because with a lower CoG you can corner just as fast without having to lean as far...

    Is this bullsh1t or is there some merit to what he's saying...
  2. My gut tells me it's crap, but I've absolutely no proof of that!

    Mind you, the Superbike School and Keith Code (quick everyone - genuflect in the direction of California!) reckon that if you initiate the turn quickly you don't need to lean as far for a given corner at a given speed.

    So I guess cruiser riders who want to keep up with their mates need to flick their bikes from vertical to banked-over as quickly as they can.
  3. Its a load of crock shite

    the low c/g has nothing to do with cornering at speed

    for example a sports bike at 60 ks an hour needs to lean the same amount as a harley at 60ks an hour

    where the diferences apply is in the chassis wheel base and the rake and trail figures

    the feeling you get is the harley MIGHT tip into corners easier at 60ks than our sports bike at 60 the same cannot be said when the same corner is taken at say 100 ks an hour and the lean angle is increased.
  4. Shit! I think it's true.

    The centrapedal force acts throught the COG. This force creates a moment about the pivot point. In this case it's the contact patch of the motorcycle.

    To conteract this moment we lean the bike.

    Now if the COG is lower then the moment is smaller, so we need to lean less.

    Where the HD saleman fall on his face is the fact that the mass is so much higher, then the cetrapedal force is that much more and this more than coneracts any benefits of the lower COG.
  5. That's the exact quote from the mag.
  6. Still a crock

    No speed range quoted no corner speed noted etc etc

    So why dont BMWs hose every body else on the road cause there aint nothing with the c of g lower than a BMW flat twin compared with a harley bloody hell using his theory it would not need to lean as much again.

    Try taking a corner on a harley at 140-160, they drag the undercarriage something fierce any of the custom style / tourers especially

    Notice they do not quantify which model ie sportster cruiser full dresser heritage etc

    then on the customs they stick racked out forks and 21" wheels the centrifugal force required to pivot that sucker from its axis of revoloution is an issue at higher speeds
  7. Look Brucey I agree that hardleys can't corner as fast as sports bike and BMWs are somewhere in between.

    As you have correctly pointed out, the factors are many.

    Depite that, if you had two bikes, equal in all respects, including mass, but one had a lower centre of gravity, the one with the lower centre of gravity would corner faster and would have to lean less to corner at the same speed for reasons stated above.
  8. All things being equal using this theory

    if you dropped the engine in your gixxer 8 inches and also dropped the seat height by the same amount. theoretically to say 60 ks an hour your lean angle could drop by say 8-10 degrees :shock:

    so i stand corrected and will take no further part in this discussion as harleys can corner faster than all sports bikes put together :oops:
    I threw up some numbers on solid works and yep you are right i blast but dont lean it over to much after the mods are done
  9. man I used to have to use solidworks. I feel for you.
  10. No way

    Solidworks is absolutely the easiest program to use mate draw a block and start hacking away

    almost finished a 500 cc single crank case to be machined from solid at my mates with a six speed box from a honda cbr600 detail work is ongoing to use a ducat 996 head on it it will run on metahnol when finished.

    Frame will be a grass tracker with leading link forks and a disc on it 21inch wheels

    Aiming for 55-60 hp total weight approx 70 kilo then the fat git riding it
  11. I hated it. It's nowhere near a intuitive as other cad programs and on a network it's as unstable as buggery.

    As to their claim it can handle thousands of parts, pfft. Mine and me fellow users solidworks would fall over with tens of parts.

    Then there's the whole user subsciption thing. They'd fix one problema nd create ten more in the process. Then once you started to use it, you couldn't go back.

    Whilst every I'm in charge of design offices, Solidworks won't set foot in the door.
  12. and get your @rse off the seat and lean your body into the corner, reducing lean angle no matter what bike you're on.

    lower C of G, effects required bike lean angle? Yup, but so does wheel/tyre width, fork rake, length of swing arm, rigidity of frame, profile of tyre, etc, etc.

    But the most important of all, Rider ability (both natural, and gained by experience etc). For the purposes of the guy in the article, it was a valid point to get more of the fairer sex, and the smaller built rider in general onto a cruiser.

    On the subject of ARR, they show the first Harley I would be interested in owning/riding, the XR1200