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  1. #1
    Epitome of Mediocrity
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    Eliminate Front Sprockets to reduce weight

    (LWB 'bent technical question from a non-tech person) If I don't need granny gears (I would still have 3-1 and hope I don't meet the "big" one), would there be any benefit to eliminating two of the three front sprockets and just going with the biggest sprocket? The weight would be reduced by two sprockets, front derailler, and shifter. Is running in 3-1 or 3-2 or 3-3 less efficient because the chain isn't running as "true" as it otherwise would if in the 2nd front sprocket?

  2. #2
    Senior Member sydney's Avatar
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    Quote Originally Posted by Glasspacker
    (LWB 'bent technical question from a non-tech person) If I don't need granny gears (I would still have 3-1 and hope I don't meet the "big" one), would there be any benefit to eliminating two of the three front sprockets and just going with the biggest sprocket? The weight would be reduced by two sprockets, front derailler, and shifter. Is running in 3-1 or 3-2 or 3-3 less efficient because the chain isn't running as "true" as it otherwise would if in the 2nd front sprocket?
    With a triple crank, mount the single ring in the middle ring position. Optimum chainline for that crank/BB.

  3. #3
    Epitome of Mediocrity
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    Thanks. So it's not a completely silly question then? I'm always fumbling to find those in-between gears anyway and prefer to just move up or down on the same ring. I must be missing something tho. If everyone is so concerned about weight, (I realize lwbs are heavier by nature but it's still an issue, or Rans wouldn't come up with an all alu V2) why doesn't this question get asked more often? Do the speedsters still want those granny gears? I know just enuf to be dangerous.

  4. #4
    Al noisebeam's Avatar
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    Quote Originally Posted by Glasspacker
    Thanks. So it's not a completely silly question then? I'm always fumbling to find those in-between gears anyway and prefer to just move up or down on the same ring. I must be missing something tho. If everyone is so concerned about weight, (I realize lwbs are heavier by nature but it's still an issue, or Rans wouldn't come up with an all alu V2) why doesn't this question get asked more often? Do the speedsters still want those granny gears? I know just enuf to be dangerous.
    When a third low gear chainring is required, it far out-benefits any weight increase. Low gears are often desired for mountain bikes for steep hills and touring for heavy loads over moderate hills. Not everybody is concerned about weight - for example if you have 80lbs of cross country gear on your bike, adding a few extra hundred grams of gearing is well worth the ability to carry that load over the Rocky Mountains into a strong headwind.

    There are many folks who only want or need 2 chainrings. And there are quite a few folks who prefer the simplicity and lower weight of one chainring. And there are still some folks that prefer the minimim weight and complexity of one chainring and one cog. One can generalize (but there are certainly exceptions) that the folks who want simplier and lighter are folks who desire speed over the flexiblity to deal with varied terrain and loads.

    Al

  5. #5
    The Rabbi seely's Avatar
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    You would probably want to consider a chainguide for a single ring setup, so any weight savings would be non existant or negligable with a single ring setup.

  6. #6
    Senior Member sydney's Avatar
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    Quote Originally Posted by seely
    You would probably want to consider a chainguide for a single ring setup, so any weight savings would be non existant or negligable with a single ring setup.
    I haven't needed one.

  7. #7
    Senior Member halfspeed's Avatar
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    Quote Originally Posted by Glasspacker
    Thanks. So it's not a completely silly question then? I'm always fumbling to find those in-between gears anyway and prefer to just move up or down on the same ring. I must be missing something tho. If everyone is so concerned about weight, (I realize lwbs are heavier by nature but it's still an issue, or Rans wouldn't come up with an all alu V2) why doesn't this question get asked more often? Do the speedsters still want those granny gears? I know just enuf to be dangerous.
    Granny gears are generally considered more important for 'bent riders because, unlike on upright bikes, the position doesn't lend itself to using body weight as leverage on steep uphills. The solution is to just spin lower gears on climbs. So, while you can go to a single chainring, you would have a harder time climbing with it than you would on a comparably geared road rig. Only you can decide if you can power over everything you would normally ride.

  8. #8
    You need a new bike supcom's Avatar
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    If you remove the rear cluster and replace the cassette hub with a freewheel hub and BMX freewheel, you can remove the rear der and shifter and just run singlespeed. You'll save even more weight.

    Better still, out on a track cog and go fixed gear. With all the weight savings, who needs more than one gear? With a fixie you can even remove the rear brake (and the front if you're really brave) and save even more weight.

  9. #9
    Senior Member Retro Grouch's Avatar
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    I wouldn't worry about chain line on a long wheelbase recumbent.

  10. #10
    crackhead
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    I say keep the gears. I mean do you carry a water bottle? Half of it weighs more than 2 chainrings.

  11. #11
    Senior Member halfspeed's Avatar
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    Quote Originally Posted by supcom
    If you remove the rear cluster and replace the cassette hub with a freewheel hub and BMX freewheel, you can remove the rear der and shifter and just run singlespeed. You'll save even more weight.

    Better still, out on a track cog and go fixed gear. With all the weight savings, who needs more than one gear? With a fixie you can even remove the rear brake (and the front if you're really brave) and save even more weight.
    A 'bent fixie? Now that would be different.

  12. #12
    Epitome of Mediocrity
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    I should just ditch the bike, save the weight, and just run. Maybe I'll take some weight off myself. (supcom you made me laugh).

    Thanks to the others for at least thinking about it. Sydney, are you running a single ring up front? Just curious.

  13. #13
    put our Heads Together cerewa's Avatar
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    Do the speedsters still want those granny gears?
    I should just ditch the bike, save the weight, and just run.
    That's a thought. If you don't go up steep hills, you probably don't need to save weight that badly. If you do go up steep hills, you need small chainrings and the weight that comes with em.
    Some awesome folks who are working to give Haitians the ability to manage their safety and their lives:
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  14. #14
    Epitome of Mediocrity
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    I noticed the Challenge Hurricane had a "big single" up front. But then I also noticed that lately they've been changing that to a triple- - apparently even the speedsters want gear range.

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