Belt Drives - the future?

Discussion in 'UK and Europe' started by Mark T, Feb 1, 2008.

  1. Mark T

    Mark T Guest

    <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>

    Now that there's a new standard out there, does anything stand in their
    way?
     
    Tags:


  2. Peter Clinch

    Peter Clinch Guest

    Mark T wrote:
    > <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >
    > Now that there's a new standard out there, does anything stand in their
    > way?


    Initially, inertia from the innate conservatism of the bike market.
    There will naturally be suspicion of a New! Improved! Thing replacing
    something that, for all its faults, works pretty well and we're familiar
    with it. Fixing something that doesn't seem to be borken, in other words.

    But I think that if it's as good as they say (okay, getting on for
    almost as good as they say...) then it will gradually appear in more and
    more bikes, so if it's going to conquer the world I'd expect it to do it
    like alloy rims replaced steel, rather than overnight. But to start
    with it does have to be that good, or it will be like DAB replacing FM
    (or not, as the case seems to be...)

    Pete.
    --
    Peter Clinch Medical Physics IT Officer
    Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
    Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
    net [email protected] http://www.dundee.ac.uk/~pjclinch/
     
  3. Nigel Cliffe

    Nigel Cliffe Guest

    Peter Clinch wrote:
    > Mark T wrote:
    >> <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >>
    >> Now that there's a new standard out there, does anything stand in
    >> their way?

    >
    > Initially, inertia from the innate conservatism of the bike market.
    > There will naturally be suspicion of a New! Improved! Thing replacing
    > something that, for all its faults, works pretty well and we're
    > familiar with it. Fixing something that doesn't seem to be borken,
    > in other words.


    It will be a shame if belt drives just die through the conservatism of the
    bike market. For a utility bike, a belt makes a lot of sense - no oil and
    should last longer. I can see how it may work well off-road. I can't see
    it ending up on race/audax machines (even though it is carbon fibre!),
    except, possibly, in the recumbent arena.


    But it will be some years in changing.





    --
    Nigel Cliffe,
    Webmaster at http://www.2mm.org.uk/
     
  4. In news:[email protected],
    Mark T <[email protected]*turn_up_the_heat_to_reply*.com.invalid>
    tweaked the Babbage-Engine to tell us:
    > <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >
    > Now that there's a new standard out there, does anything stand in
    > their way?


    o Can't be retrofitted to an existing bike (or can it?)
    o hub gears only so gear range is of necessity limited even if one can
    afford a Rohloff

    --
    Dave Larrington
    <http://www.legslarry.beerdrinkers.co.uk>
    Trees, once grown in large numbers, make perfect forests.
     
  5. On 1 Feb, 13:23, "Nigel Cliffe" <[email protected]> wrote:
    > It will be a shame if belt drives just die through the conservatism of the
    > bike market. For a utility bike, a belt makes a lot of sense - no oil and
    > should last longer. I can see how it may work well off-road. I can't see
    > it ending up on race/audax machines (even though it is carbon fibre!),
    > except, possibly, in the recumbent arena.


    I can see them being popular in commuting / city bikes. The width of
    the belt, and the lack of lateral flex, means a fixed chainline and no
    derailleur, so it'll only work with hub gears. But that's not much of
    an 'only', considering there's a big market for people who only need a
    few gears. As you say, for a utility bike it's seems like a good
    thing. Oh, and it won't rust in the winter, which reminds me I need
    to do some chain TLC this weekend...

    Colin
     
  6. _

    _ Guest

    On Fri, 1 Feb 2008 13:23:14 -0000, Nigel Cliffe wrote:

    > Peter Clinch wrote:
    >> Mark T wrote:
    >>> <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >>>
    >>> Now that there's a new standard out there, does anything stand in
    >>> their way?

    >>
    >> Initially, inertia from the innate conservatism of the bike market.
    >> There will naturally be suspicion of a New! Improved! Thing replacing
    >> something that, for all its faults, works pretty well and we're
    >> familiar with it. Fixing something that doesn't seem to be borken,
    >> in other words.

    >
    > It will be a shame if belt drives just die through the conservatism of the
    > bike market. For a utility bike, a belt makes a lot of sense - no oil and
    > should last longer. I can see how it may work well off-road. I can't see
    > it ending up on race/audax machines (even though it is carbon fibre!),
    > except, possibly, in the recumbent arena.
    >


    Efficiency, beloved by racers and marketing droids, will be a big issue.
    Bigger than it should be, probably; and murkier, certainly.

    My recollection is that previous versions of belt drives were estimated to
    be less efficient that a well-lubricated new roller chain. Belts do not
    lend themselves well to derailleur gear systems, and that would add the
    typical lower efficiency of hub gearing.

    Cleanliness is a possible advantage - but if you are going to have a hub
    gear, you might as well have a chaincase; which would probably also remove
    or reverse any durability advantage.

    Howevere, this will be (sort of) "new", and manufactures love "new" - it
    means that they can sell stuff to (some of) the installed base.
     
  7. Peter Clinch

    Peter Clinch Guest

    _ wrote:

    > Efficiency, beloved by racers and marketing droids, will be a big issue.
    > Bigger than it should be, probably; and murkier, certainly.
    >
    > My recollection is that previous versions of belt drives were estimated to
    > be less efficient that a well-lubricated new roller chain.


    But a lot of the point of this new one is it's meant to be just as
    efficient as a chain.

    > Belts do not
    > lend themselves well to derailleur gear systems, and that would add the
    > typical lower efficiency of hub gearing.


    It is typical, but it's also changing. Hubs have come on a long way in
    recent years while derailleurs haven't really changed /that/ much. if
    they continue to improve (particularly the likes of the NuVinci CVT hub,
    which just needs to get lighter AFAICT) this may start to be less of an
    issue.

    > Cleanliness is a possible advantage - but if you are going to have a hub
    > gear, you might as well have a chaincase; which would probably also remove
    > or reverse any durability advantage.


    I don't think so. An enclosed chain still needs lubrication, while a
    drive belt doesn't.

    It does have some clear advantages... as long as you don't particularly
    need derailleurs for your particular application (and "need" can be
    factored in as cost: they're popular at the low end in part because
    they're not very sophisticated and thus cheap).

    Pete.
    --
    Peter Clinch Medical Physics IT Officer
    Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
    Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
    net [email protected] http://www.dundee.ac.uk/~pjclinch/
     
  8. dabac

    dabac Well-Known Member

    Joined:
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    Retrofit would require a splittable (or spliceable) belt. Not impossible, but not yet here.

    You need to consider that snowmobiles, certain cars and various other vehicles have been using belt drives for years under the catchy phrase of CVT (continously variable transmissions).
    Granted, an entirely different kind of belt compared to what usually discussed as the potential future of bicycles, but still a belt...

    I wonder how the bike (marketing) industry would cope with a CVT-equipped bike? With no longer being able to use the number of gears to separate categories, what would they do instead?
     
  9. Peter Clinch

    Peter Clinch Guest

    dabac wrote:

    > I wonder how the bike (marketing) industry would cope with a
    > CVT-equipped bike? With no longer being able to use the number of gears
    > to separate categories, what would they do instead?


    Google NuVinci, it's been released in the fairly recent past and
    according to all the reviews I've seen thus far works very well indeed.
    the current Gotcha is the hub weighs about 4 Kg, which is a lot in bike
    terms. But it's version 1, I imagine it will improve.

    Personally, I'd love CVT, just as soon as the costs and weights come
    down (previous implementations have been rather inefficient AIUI, but
    from what i read the NuVinci has got at least most of that sorted).
    Rather than say "27 gears" you could differentiate bikes with practical
    gear range, which unlike the "27 gears" would actually impart some
    useful information... so I guess marketing might not like it so much... ;-/

    Pete.
    --
    Peter Clinch Medical Physics IT Officer
    Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
    Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
    net [email protected] http://www.dundee.ac.uk/~pjclinch/
     
  10. bugbear

    bugbear Guest

    dabac wrote:
    >>
    >> o hub gears only ..

    > You need to consider that snowmobiles, certain cars and various other
    > vehicles have been using belt drives for years under the catchy phrase
    > of CVT (continously variable transmissions).


    IIRC such transmissions have losses that aren't
    acceptable on a HPV.

    BugBear
     
  11. _

    _ Guest

    On Fri, 01 Feb 2008 14:17:44 +0000, Peter Clinch wrote:

    > dabac wrote:
    >
    >> I wonder how the bike (marketing) industry would cope with a
    >> CVT-equipped bike? With no longer being able to use the number of gears
    >> to separate categories, what would they do instead?

    >
    > Google NuVinci, it's been released in the fairly recent past and
    > according to all the reviews I've seen thus far works very well indeed.
    > the current Gotcha is the hub weighs about 4 Kg, which is a lot in bike
    > terms. But it's version 1, I imagine it will improve.
    >
    > Personally, I'd love CVT, just as soon as the costs and weights come
    > down (previous implementations have been rather inefficient AIUI, but
    > from what i read the NuVinci has got at least most of that sorted).


    Well, it's about 8 lbs and there's a suspicious absence of efficiecy
    figures on their website, which typically for lubricated CVT drives is in
    the range of 80-90%. Roller chains (can) do much better.
     
  12. Paul Boyd

    Paul Boyd Guest

    Dave Larrington said the following on 01/02/2008 13:42:

    > o Can't be retrofitted to an existing bike (or can it?)


    Not unless you take a hacksaw to your chainstay. Orange basically did
    this, then cut'n'shut the join.

    --
    Paul Boyd
    http://www.paul-boyd.co.uk/
     
  13. Paul Boyd

    Paul Boyd Guest

    Nigel Cliffe said the following on 01/02/2008 13:23:
    > I can see how it may work well off-road.


    I'm not so sure - what happens when a great big splot of mud or a stone
    lands on the belt? Where does it go when it reaches the pulleys?

    --
    Paul Boyd
    http://www.paul-boyd.co.uk/
     
  14. _

    _ Guest

    On Fri, 1 Feb 2008 13:42:17 -0000, Dave Larrington wrote:

    > In news:[email protected],
    > Mark T <[email protected]*turn_up_the_heat_to_reply*.com.invalid>
    > tweaked the Babbage-Engine to tell us:
    >> <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >>
    >> Now that there's a new standard out there, does anything stand in
    >> their way?

    >
    > o Can't be retrofitted to an existing bike (or can it?)


    Oooo, yes.

    That'd have to be a design challenge; either a separable belt, a detachable
    chainstay, or a frame made to be disposable if the belt should fail.

    I bet Shimano goes for #3.
     
  15. Pete Biggs

    Pete Biggs Guest

    Mark T wrote:
    > <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >
    > Now that there's a new standard out there, does anything stand in
    > their way?


    Some questions that come to mind:

    1) Has it been independently tested to see if efficiency really is as high
    as with a conventional chain - and at high torque? Or do we just have the
    designer's word for it?

    2) Could the belt ever slip?

    3) How critical is belt tension? Will the usual methods of tensioning be
    adequate?

    4) How long will it last? Will it wear out from friction?

    5) What kind of sprockets will be needed, and what chainsets and hubs will
    they fit?

    6) How much will the chain and sprockets cost?

    ~PB
     
  16. Mark

    Mark Guest

    In article <[email protected]>,
    [email protected] says...
    > On Fri, 1 Feb 2008 13:42:17 -0000, Dave Larrington wrote:
    >
    > > In news:[email protected],
    > > Mark T <[email protected]*turn_up_the_heat_to_reply*.com.invalid>
    > > tweaked the Babbage-Engine to tell us:
    > >> <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    > >>
    > >> Now that there's a new standard out there, does anything stand in
    > >> their way?

    > >
    > > o Can't be retrofitted to an existing bike (or can it?)

    >
    > Oooo, yes.
    >
    > That'd have to be a design challenge; either a separable belt, a detachable
    > chainstay, or a frame made to be disposable if the belt should fail.
    >
    > I bet Shimano goes for #3.
    >

    Or:
    http://mos.bikeradar.com/images/news/2007/Eurobike/Wednesday/Cannodale-
    conceptedit-798-99.jpg
    --
    Cheers,
    Mark
     
  17. Paul Boyd <[email protected]> wrote:

    > Nigel Cliffe said the following on 01/02/2008 13:23:
    > > I can see how it may work well off-road.

    >
    > I'm not so sure - what happens when a great big splot of mud or a stone
    > lands on the belt? Where does it go when it reaches the pulleys?


    mmm yes, think just water on the fan belt in a car.

    roger
    --
    www.rogermerriman.com
     
  18. Mark T
    <[email protected]*turn_up_the_heat_to_reply*.com.invalid>
    wrote:

    > <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>
    >
    > Now that there's a new standard out there, does anything stand in their
    > way?


    needs to be a fair bit cheaper to make or make faster bikes? hopefully
    both. being simple and easy maintain probably will not sell at least
    well.

    the problem is the chain is attually very good.

    roger
    --
    www.rogermerriman.com
     
  19. bugbear <[email protected]_papermule.co.uk_trim> wrote:

    > dabac wrote:
    > >>
    > >> o hub gears only ..

    > > You need to consider that snowmobiles, certain cars and various other
    > > vehicles have been using belt drives for years under the catchy phrase
    > > of CVT (continously variable transmissions).

    >
    > IIRC such transmissions have losses that aren't
    > acceptable on a HPV.
    >
    > BugBear


    on a about town bike, i'd be quite happy to take some losses for some
    conviences

    roger
    --
    www.rogermerriman.com
     
  20. On Feb 1, 4:26 pm, "Pete Biggs"
    <[email protected]> wrote:
    > Mark T wrote:
    > > <www.bikebiz.com/news/29367/Carbon-belt-drives-are-standardised>

    >
    > > Now that there's a new standard out there, does anything stand in
    > > their way?

    >
    > Some questions that come to mind:
    >
    >
    > 2) Could the belt ever slip?

    It looks like a toothed belt to me so no, it will never slip. (Much as
    the cambelt on a car never slips - at least, if it does you've got a
    very expensive problem to sort out)

    >
    > 3) How critical is belt tension? Will the usual methods of tensioning be
    > adequate?

    Probably not very although efficiency might vary a lot if it's not
    quite right. On something like a Brompton where you have to have a
    chain tensioner then the tension should always be right.

    At 95% of the efficiency of a chain, and no maintenance or oil at all
    I'd be very interested in this on something like the Brompton which is
    a "get me about" bike. At 99% efficiency I'd want this on the
    Brompton. Not sure about my other bikes - would be nice on the
    windcheetah but the width might be an issue and there would have to be
    some sort of different gearing.

    Tim.
     
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