prop shaft

hamboman
hamboman Posts: 512
edited July 2007 in MTB general
Have any manufacturers ever tried to build a bike with one, instead of a chain, I was thinking? Because I was looking at the gearbox contraptions some bikes now have and thought how heavy and complicated they must be! Why not just shove in a heavy but ultra reliable prop?!
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Comments

  • nicklouse
    nicklouse Posts: 50,673
    many. biomega is a bigish producers of bikes with shaft drive, But there are not many shaft driven MTB's as the gearing is still a bit limited.

    http://www.biomega.dk/biomega.aspx
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Splasher
    Splasher Posts: 1,528
    A bevel gear on your rear hub doesn't do much for your unsprung mass either!
    "Internet Forums - an amazing world where outright falsehoods become cyber-facts with a few witty key taps and a carefully placed emoticon."
  • nicklouse
    nicklouse Posts: 50,673
    Splasher wrote:
    A bevel gear on your rear hub doesn't do much for your unsprung mass either!

    interesting concept there. throwing rear sus in there like that.

    not that simple.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mc
    mc Posts: 70
    nicklouse wrote:
    Splasher wrote:
    A bevel gear on your rear hub doesn't do much for your unsprung mass either!

    interesting concept there. throwing rear sus in there like that.

    not that simple.
    Wouldn't be that hard. Would just invole a slip joint, and a couple suitable pivots. Wouldn't even need any universal or CV joints if designed right.

    Still wouldn't have one though. The weight of suitable gears with adequate sealing would easily outweight a conventional mech set-up.
  • Anonymous
    Anonymous Posts: 79,665
    BMW use shaft drive for their touring motorbikes.
    However, all performance motorcycles still use chain drives.
    Surely that suggests chain drives have a performance advantage?
  • nicklouse
    nicklouse Posts: 50,673
    mc wrote:
    nicklouse wrote:
    Splasher wrote:
    A bevel gear on your rear hub doesn't do much for your unsprung mass either!

    interesting concept there. throwing rear sus in there like that.

    not that simple.
    Wouldn't be that hard. Would just invole a slip joint, and a couple suitable pivots. Wouldn't even need any universal or CV joints if designed right.

    Still wouldn't have one though. The weight of suitable gears with adequate sealing would easily outweight a conventional mech set-up.

    it would need a bit more the shaft would have to beable to change length. Or the pivot will have to be in the same place as the sus pivot.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mc
    mc Posts: 70
    nicklouse wrote:
    it would need a bit more the shaft would have to beable to change length. Or the pivot will have to be in the same place as the sus pivot.

    Erm, slip joint? ie. a two part shaft joined by a splined section..... ;-)
  • nicklouse
    nicklouse Posts: 50,673
    tes but it is adding extra weight and stuff to get crudded up and then in will also have to clear any suspension linlages.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mc
    mc Posts: 70
    nicklouse wrote:
    tes but it is adding extra weight and stuff to get crudded up and then in will also have to clear any suspension linlages.
    :lol:
    Let's just sum up with, chains work.
  • nicklouse
    nicklouse Posts: 50,673
    but shafts work very well also. but i have yet to see a better soulution than a chain though.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Red Panda
    Red Panda Posts: 269
    yeehaamcgee wrote:
    BMW use shaft drive for their touring motorbikes.
    However, all performance motorcycles still use chain drives.
    Surely that suggests chain drives have a performance advantage?
    I take your point but in fact BMW use shaft drive on their 167bhp K1200S, the fastest sports bike they've ever made. As well as Buell using a belt drive on their 146bhp 1125R sports bike.
  • nicklouse
    nicklouse Posts: 50,673
    Red Panda wrote:
    yeehaamcgee wrote:
    BMW use shaft drive for their touring motorbikes.
    However, all performance motorcycles still use chain drives.
    Surely that suggests chain drives have a performance advantage?
    I take your point but in fact BMW use shaft drive on their 167bhp K1200S, the fastest sports bike they've ever made. As well as Buell using a belt drive on their 146bhp 1125R sports bike.

    and a lot of cars i know producing way more power than those bikes use chains to put the power into the gear box from the crankshaft.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • red eye
    red eye Posts: 264
    nicklouse wrote:
    Red Panda wrote:
    yeehaamcgee wrote:
    BMW use shaft drive for their touring motorbikes.
    However, all performance motorcycles still use chain drives.
    Surely that suggests chain drives have a performance advantage?
    I take your point but in fact BMW use shaft drive on their 167bhp K1200S, the fastest sports bike they've ever made. As well as Buell using a belt drive on their 146bhp 1125R sports bike.

    and a lot of cars i know producing way more power than those bikes use chains to put the power into the gear box from the crankshaft.
    how would that work? as the crank has the flywheel and clutch assembly bolted to it which then drives the gearbox even with an autobox power is transmitted from crank direct to the box. i have never seen a chain power a gearbox
  • red eye
    red eye Posts: 264
    i lie the mini's gearbox is driven by chain
  • Red Panda
    Red Panda Posts: 269
    red eye wrote:
    i lie the mini's gearbox is driven by chain
    Ooooooo...the Power!!! :wink::)
  • nicklouse
    nicklouse Posts: 50,673
    red eye wrote:
    i lie the mini's gearbox is driven by chain

    no it is not it is cogs, there was a aftermarket chain drive kit some time in the '70's.

    i was thinking of other cars... :)
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • red eye
    red eye Posts: 264
    was it? its been ages since i worked on a mini
    any way what car had a chain driven gearbox its going to bug me now!
  • red eye
    red eye Posts: 264
    Red Panda wrote:
    red eye wrote:
    i lie the mini's gearbox is driven by chain
    Ooooooo...the Power!!! :wink::)
    hey dont knock the minis raw power :P
  • nicklouse
    nicklouse Posts: 50,673
    lets say 2.3L turbo 4 cylinder FWD longditudinal engine on top of the box.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • red eye
    red eye Posts: 264
    nicklouse wrote:
    lets say 2.3L turbo 4 cylinder FWD longditudinal engine on top of the box.
    all i can think of is range rover they had a chain driven transfer box
  • nicklouse
    nicklouse Posts: 50,673
    red eye wrote:
    nicklouse wrote:
    lets say 2.3L turbo 4 cylinder FWD longditudinal engine on top of the box.
    all i can think of is range rover they had a chain driven transfer box

    nope.

    the clue is where i am.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • red eye
    red eye Posts: 264
    you like being difficult dont you
  • nicklouse
    nicklouse Posts: 50,673
    a SAAB.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • red eye
    red eye Posts: 264
    i was going to say that :roll:
  • Red Panda
    Red Panda Posts: 269
    I was gonna say Volvo! :)
  • nicklouse
    nicklouse Posts: 50,673
    Ok the chains are fairly FAT trippel row...

    and there is one guy running about 700bhp through it!

    too much power for a FWD but it does make smoke!
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • red eye
    red eye Posts: 264
    700bhp :shock: that must be a very entertaing drive
  • nicklouse
    nicklouse Posts: 50,673
    i dont think drive is the word.

    there is a guy called Yesus very good welder. has an old Volvo with 1000bhp and it is road legal!!

    spins the wheels to much.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Anonymous
    Anonymous Posts: 79,665
    There's also some suzuki off-roader which has (IIRC) a chain drive linking the front and rear differentials.

    I still think my point abut performance bikes using chains still stands.
    If there was a proper advantage to shaft-driven bikes over chain driven, then far more manufacturers would have made their racing bikes chain drive, no?
    It's not like superbikes, or GP bikes are new, and it'n not like shaft drive is new.

    Also, the belt drive on Buell's bike isn't really that much of a departure from a chain.
    I've seen a few custom 'hogs' using a belt drive.
  • Red Panda
    Red Panda Posts: 269
    yeehaamcgee wrote:
    However, all performance motorcycles still use chain drives.
    Not true though is it as I have given two rather obvious examples of hyper sports bikes that don't use chain drive.

    Chain drives are cheaper for motorbike manufacturers than shaft drives as they are cheaper to make and pass the onus onto the owner to maintain them. The problem being that they get dirty, hook sprocket teeth over and stretch. It's prudent to replace chain and sprocket kits at the same time on a motorbike isn't it. Not cheap in the long term at around 130 quid per kit.

    Shaft drive's can have torque problems on motorbikes that means they can handle weirdly when putting power down on bends...having said that they are cheaper to maintain.

    Harley's aren't really what I'd call a 'performance motorcycle', hence my example of a Buell 1125R which is a lightweight bike with 146bhp.
    I wouldn't say a chain drive is the same as a belt drive, albeit similar.

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