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Shaft drive pros & cons?

Discussion in 'Bling and Appearance' at netrider.net.au started by Lectre, Oct 28, 2007.

  1. Hey all.
    Was wondering what the pros and cons were to shaft drive bikes?
    was thinking about getting something cheap and oldschool (like a 1980 yamaha xs1100) for running around in wet weather (I HATE getting the 'fighter wet).

  2. Shaft drive keeps the back of the bike clean because there's no yucky chain oil involved.

    And the Excessive Elephant wouldn't be a bad wet-weather tool; it weighs so much it would cut right through the water to the tarmac below :LOL:.
  3. y'know the feeling when you are sitting in your v8 and you punch the throttle and the front left corner of the car rises slightly, by act of torsional throw-out?
    the only shafty i ever rode had a noticeable "throwout" similar to this upon hard acceleration out of corners.
    wasnt bad, just noticeable.
  4. Pros; relatively maintenance free and clean

    Cons; expensive if something goes wrong, can leave you stranded waiting for parts, robs horsepower, can't change ratios easily, weight and as Joel mentioned, backlash can be a problem on older bikes
  5. Unless it's a sideways twin like Guzzi, BMW boxer, or a Honda CX, you won't feel any sideways torque. That comes from the engine design
    not from the shaft.

    Most bikes you won't feel any difference to a chain
    setup, unless you are REALLY hammering.

    Shaft drive lasts almost forever with almost no maintenance (change rear drive gear oil every 30,000km $5, grease at grease points $1).

    Downside ... very little choice in shaft drive bikes, and most of them are tourers which have done loads of mileage. However, most have engines which are designed to do loads of miles.
  6. True

    Not so true.

    Unless it's a recent BMW or Moto Guzzi with a non-reactive link built into the final drive assembly you will notice the back end rise as you accelerate, especially at take off, and fall as you decelerate. This can be quite noticeable, and off-putting, around roundabouts, especially.


    Trevor G
  7. A chain or belt is the most efficient means of motivation.
    Chain and sprockets weigh much less leading to better suspension movement, acceleration and braking.
    For those of us who clean our bikes regularly there is minimal extra effort required due to the chain. You will have brake dust to clean anyway.
    Good chains and sprockets last and allow gearing changes.

    If the bike I wanted had a shaft that would be ok, but I wouldnt be buying just because it had one over a chain, belt drive bike.
  8. Shaft drive bikes are generally less hassle to own if you are a high distance rider.

    Cleaning and oiling a chain isn't a big hassle every 1000kms if you only do 5000kms a year but if you do 25000kms a year it can be. Also at those sorts of distances one is getting to a chain and sprockets replacement every year or two and that sort of cost impost adds up.

    Older shaft drive bikes will have shaft reaction... the back of the bike will either lift up or squat down in corners under acceleration or braking. It's not the end of the world but it can be felt. The heavier the bike and the longer the shaft the less it tends to be felt (which is why bikes like the GTR1000 have minimal shaft drive effect despite having no special torque compensation).

    The newer BMW's and Guzzi's have special lever-arm arrangments which act to counteract the shaft drive effect and reduce it significantly.

    I can hardly feel the shaft effect on my V11 compared to the Yamaha Diversion 900S I used to own.
  9. err, bullshit.
    i felt it clearly on an i4 spewzuki.
  10. Joel what you could feel wasn't sideways torque reaction it was vertical torque reaction.

    The rear end extends and compresses with the torque reaction from the motor and that alters the steering geometry of the shaft drive motorbike by altering the height of the rear end (and hence the angle of the front end) causing it to either push wide or pull into the corner.

    That is the 'sideways' force you felt but it wasn't sideways torque it was a secondary reaction to a vertical torque.

    The sideways torque that one can feel on a Guzzi or BMW twin OTOH is a result of the heavy longitudinal crank shaft shaft spinning up.

    If I 'blip' the throttle in neutral on my Guzzi (with the bike not moving and the shaft not spinning) then the sideways torque reaction still happens and the bike pulls towards the left.

    It's a similar effect to a hand held power drill being revved up (they tend to twist in your hand).

    Whilst both the shaft drive effect (longitudinal) and the sideways torque effect are real they are two different issues.
  11. Then there was something else Very Wrong with that suzi which was causing the feeling. Could have been twisted forks, swingarm, or frame, or a bad shock on one side.

    I reckon you're right.
    I have had 2 GTR1000s and neither showed torque reaction or lift unless cornering at extreme angles (ie. hard parts scraping). Same with BMWs and FJRs I've ridden. However XVS1100 had it noticeably.
  12. Dont forget guys that most of the modern BMW's etc run contra rotaing gearboxes now ala CX500 thats why there is no noticable rise and fall under power its the dynamics of having an engine spinning one way and the mass of the clutch and geabox spinning the other.

    Thats why CX hondas only kick to the right with the clutch in at the lights and they dont have long swing arms or reaction arms to keep them short.

    thats why the laverda V6 had its swingarm pivited off the engine cases it was a conventional engine gearbox in line with a single plate clutch ala guzzi / round head boxer the problem was torque reaction once the engine went over 100 bhp when they got it to 140 it would tie itself in knots ie totally lock the swingarm and they had no time to redesign for a contra rotating box/clutch assembly.

    dont forget classic riding lines either it can be of huge benifit to brake in a straight line and then power through a corner with the back end rising under power ie more ground clearance and tightening up the head angle also a reason that in the 80s etc certain bikes where thought of as better higher speed point to point bikes ie melbourne to bathurst etc

    just some comments
  13. It's well known fact that you can't wheelie or countersteer on a shaftie.
  14. Tried to do a wheelie on the BMer - not gunna happen!! Even though she is about 250kg I thought I may be able to but looks like I am stuck in the the boring old fart position!

    I can live with that!

    Must say that the low maintenance of the shaft drive is a mighty fine thing!

  15. Pretty well covered above, but I'll throw in that moderns shafts are expensive to replace. To the point where there is no price advantage over chains and sprockets in the long run.

    Convenience is the only real seller these days.
  16. Loz...I think you've been misled with some facts. :)
    Just because you can't change the sprocket size....don't mean you can't.


    And it is a Kawasaki (1000GTR).

    There's a recent pic of a 1400GTR with it's front wheel in the air too. Damn, can't find it ATM. :facepalm:

    Someone has been telling you porky pies? :?
  17. I have to disagree. I've owned about 30 bikes in the last 30 years.

    In that time I have replaced (wait for it)... ZERO shaft drives.

    Some of those bikes have had up to 80,000kms on them.

    Shaft drive replacements costs aren't something that new bike buyers have to worry about as a rule (only buyers of 2nd hand bikes and only then when they have high kms on them).
  18. Starts Counting... That's 1.

    Oh... and that GTR shot is obviously photo shopped! :)
  19. There are many 1000GTR's that have run in excess of 200,000km, that have never had problem wiht the shafts. I don't know if any of the Yam XJ series had problems though.

    Photoshopped you say? Why?

    Maybe both these are too?

  20. Bah, they've just filled the panniers with lead and staged those shots :).