A daft question?

grantus
grantus Posts: 690
edited September 2008 in Road general
Can someone possibly explain to me the concept of 'the perfect gear' for single speeding a bike with vertical dropouts?

Surely you would just take as many links out the chain to give you as good a tension as possible for any given combination of chainring and sprocket?

Or am I missing something :D :?:
www.westlothianclarion.co.uk

Comments

  • Greenbank
    Greenbank Posts: 731
    Yes, for single-speed you don't care if there's any slack in the chain. Just take out as many links as you can and Robert is indeed your avuncular relation.

    For fixed you want to make sure the chain is tight.

    http://www.63xc.com/toddp/halflink.htm
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  • david 142
    david 142 Posts: 227
    The basic idea underlying the "Magic Gear" is that the amount of chain required to partially wrap around ring and sprocket doesnt exactly add up tp a whole number of chain links. This is because it is only partially wrapped round - it fits exactly from tooth to tooth but theres a "bit extra" involved as the chain meets and leaves the sprocket. The precise size of this bit varies with the radius of the toothed wheel, so some combinations give a better approximation to a whole number of links than others.
    At least, that's what I was told... :lol:

    Sometimes a Ghost ring can help things along... :?
  • pete.whelan
    pete.whelan Posts: 788
    get one of those chain made from half-links, not only are they very smooth but also allow finer adjustment to the chainlength.

    sorry, can't remember who makes them. It might be KMC
    Recipe: shave legs sparingly, rub in embrocation and drizzle with freshly squeezed baby oil.
  • grantus
    grantus Posts: 690
    It's all a bit over my head I'm afraid!! :oops: 8) :oops:

    I've bought a chain tensioning device that looks like half a rear mech.

    That will hopefully do the trick as I won't be running fixed - just single speed as it's a mountain bike I'm converting. Not quite up to running fixed offroad yet! :wink:

    Just don't want to be stopping on every descent to put my chian back on!
    www.westlothianclarion.co.uk
  • nicklouse
    nicklouse Posts: 50,675
    the perfect gear is the combination of front and rear cogs that allows you to use a normal chain and no tensioner and have a chain that is not too tight or slack.

    half link chains can be used if the chain can not be used as is. But they do stretch/wear faster than normal chains. Also you can add a single half link to a normal chain.

    Ghost rings .... Ghetto.. :lol:
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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  • david 142
    david 142 Posts: 227
    nicklouse wrote:
    Ghost rings .... Ghetto.. :lol:

    Not everyones cup of tea I'll grant you. Its just that I always find myself staring in fascination waiting for it to fall off... :lol:
  • gkerr4
    gkerr4 Posts: 3,408
    what on earth is a 'ghost ring'??
  • demmerson
    demmerson Posts: 91
    gkerr4 wrote:
    what on earth is a 'ghost ring'??
    It's a chainring inserted between the upper and lower runs of the chain. It isn't attached to anything and is just held in place by the chain tension. Like this http://ctmtblog.blogspot.com/2008/03/gh ... -ring.html

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