When did dual range transmissions disappear

Discussion in 'Thumpers' started by FlownOver, Oct 28, 2011.

  1. Woodsrat

    Woodsrat Gone ridin'

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    Oh yeah--forgot about big flywheels, too and their effect on clean running at low speeds.

    I own a Gas-Gas Pampera--one of the early ones that's more trials bike than enduro--and while it won't go down a beaten trail at speed very well when the going gets rough it'll idle through with no clutchwork or wheelspin whereas my riding buddies on their thoroughbred enduro bikes are spinning their rear wheel or slipping their clutch. It has a wide ratio six speed gearbox with an overdrive sixth gear that allows for good road speed even with trials gearing.

    Maybe a simple revamp of the gearbox ratios in adventure bikes would be a tremendous improvement.
    #41
  2. Mr. Canoehead

    Mr. Canoehead Taste Gunnels!

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    I think you got it backwards - a larger front sprocket raises gearing a smaller sprocket lowers gearing. The problem is that you can't get a small enough front sprocket to lower the ratio enough. 13 teeth seems to be the minimum.

    The pizza sprocket would go on the back. :lol3

    As for the CB900C reference - I remember from the road tests of the day that the dual range was a result of having to mate a chain drive engine to a shaft drive chassis. Honda happened to have a dual range box that fit the bill, so in a clever bit of parts-bin engineering, they made it a marketing feature.
    #42
  3. ineptizoid

    ineptizoid I'm scared hold me

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    This
    #43
  4. Countdown

    Countdown Long timer

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    My god 4.38 is off the chart! Hard to believe it had enough power to pull the gear changes.

    See post 28

    http://www.advrider.com/forums/showpost.php?p=18521366&postcount=28
    #44
  5. kpt4321

    kpt4321 Long timer

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    There are lots of benefit to (reasonably) tight gearing too, guys. Not everybody wants to ride at a walking pace and have to run an engine through a huge rev range before they can shift.
    #45
  6. Woodsrat

    Woodsrat Gone ridin'

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    ...And this puts us back to the reason we need some sort of reduction box. If ALL the ratios are lowered the gaps between the gears become redundant.

    Here's a thought--instead of putting the reduction box on the output side of things why not incorporate it in the primary drive??? I haven't sat down and done the math to see what kind of change might be necessary to get some plonk out of the motors currently available but it might be a possibility.

    As for Mr. kpt4321's comment about his computations of the speed of the DRZ & WWR--if you can walk alongside an idling bike at six or even four miles an hour while walking it through rough terrain you're obviously in a lot better shape than the rest of us. You probably even have the ability and fearlessness to attack these sections at speed as well. My advice to you is to go enjoy your bike and let us old phucks whine about the fact that most modern bikes simply don't work for us. Anyone who's managed to get their KLR, DR, XR-L, G/S or whatever in a pickle of a situation and overheated their clutch from trying to get through it can definitely relate to what's been discussed here.

    My guess is, however, that in the real world the ability to be able to walk alongside a typical "adventure" bike without having to work the shit out of the clutch or run alongside it would be a benefit to everyone--unless, of course, they stay on the bunny trails or asphalt.:lol3
    #46
  7. jlw

    jlw Adventurer

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    Check out


    Dual Ratio Sprockets


    Would it work for Dual Sporting? Currently it is only on a selected sport bikes for stunting.

    This is from a recent email correspondence



    Thank you for your interest in the DRS product. Yes we will be expanding the DRS line into other areas of the motorcycling world in the future. Besides being a long time stunter i am also a avid dual sport rider. However Stunting is what we know best so it was a logical place for us to start when introducing the product for the first time. So unfortunately at this point we do not have anything to offer for your machine. But check with us once in a while as we will keep tabs on requested models by customers.


    Thank you

    Richard

    The DRS team.
    #47
  8. lgottler

    lgottler Been here awhile

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    My first bike was my dad's Suzuki TS185. 2 stroke with dual range transmission. I tooled all around our property in the woods using only low range. A couple times I took a risk and jumped it into high range and went racing down the road at a breakneck speed of 40mph! (hey at 14 and first bike, that was as fast as I dared go!).

    Nabbed a pic off google...
    [​IMG]

    I also agree with a few others here that a low first would be ideal, then use standard gears on up.
    #48
  9. Old Kiwi#99

    Old Kiwi#99 Been here awhile

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    Putting 6 speeds into a case designed for 5 means that the gears are going to have to be a lot narrower. Some of the 650 dual sports have enough trouble keeping the standard 5 speed gears together. (DRs anyone?)

    Anyway, KLRs do have a 6 speed - the owners manual says so..:wink:.
    #49
  10. eepeqez

    eepeqez Long timer

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    They're still in production.

    They're still in production!

    [​IMG]

    Kawasaki Super Sherpa, 282.1lbs, and first and sixth gears are far enough apart that you don't need a splitter box to get both very slow and 60mph gears.

    They're NOT DEAD YET!!!

    In fact the CT110 postie bike is the biggest selling motorbike in Australia by such a large margin that they specifically exclude thm from the sales statistics.

    [​IMG]

    Oh sorry, have to be able to register ("tag") it?

    [​IMG]


    The CT is an aggie bike, designed for following sheep around a paddock at walking pace.
    It also suits anyone else who wants to wander around at slow speeds while doing useful stuff like delivering mail, but high speed is not a strong point.

    The Stockman is a modern aggie bike, with a short seat you can reach the ground, low enough gearing you can go walking pace and enough power that you won't get trampled if you venture into traffic (though it can't be registered in Australia).

    The Sherpa is it's flashy cityboy cousin.
    #50
  11. Woodsrat

    Woodsrat Gone ridin'

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    Do you happen to know what the first, primary and final drive ratios are on the Stockman? The U. S. spec Super Sherpa has a first gear that's about as tall as the XR-250R's second gear. At least on the ones we get they definitely don't have any ability to go slow without clutchwork.

    The XR-250R (and the CRF-250X) both have low gear overall first gear ratios of around 32:1, for reference (first gear ratio x the primary ratio x the final drive ratio). There are others but the U. S. spec Super Sherpa ain't one of them.

    In it's low range in first gear the CT's low gear overall ratio is 50:1 +

    Yeah, the CT-110 might still be in production but we'll never see 'em again in the U. S...:(:
    #51
  12. eepeqez

    eepeqez Long timer

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    Here are some numbers someone else has collected, basically ratios between first and top gears; you can shift the entire range about by changing sprockets, but you can't shift the ratios between the gears.

    The Sherpa is sold in the US with an on road emphasis. The Stockman aggie is geared down about 25% relative to the Sherpa.

    #52
  13. Brute

    Brute Melbourne , outer east .

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    I had a 1974 CZ 400 that had an 8 speed gearbox . 4 gears & 4 neutrals :rofl
    #53