Converting to Microdrive?- Mtbr.com
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  1. #1
    1GEAR
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    Converting to Microdrive?

    Would love the extra clearance even though it is not totally needed, pretty sure I have the wrong crank set to run micro. Whats the smallest I could run without replacing the crank set or hub?

    Bike in question:


  2. #2
    Drinking the Slick_Juice
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    you can run a 12 on the cassette, good luck finding a single speed cog
    "If women don't find handsome , they should at least find you handy."-Red Green

  3. #3
    Retro Grouch
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    Quote Originally Posted by Efff
    Would love the extra clearance even though it is not totally needed, pretty sure I have the wrong crank set to run micro. Whats the smallest I could run without replacing the crank set or hub?
    Assuming your crank is a 104 BCD, your stuck with 32t.
    Just one more rep and I get the toaster!

  4. #4
    one chain loop
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    micro drive is for show bikes and non-riders.
    everything sucks but my vacuum cleaner.

  5. #5
    i also unicycle
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    microdrive is for bmx bikes or jump bikes. and works great for such things.
    mtbr says you should know: i work in a bike shop.
    bikes & beers (on my blog) http://idontrideenough.blogspot.com/

  6. #6
    Beware the Blackbuck!
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    There are 30t 104 bcd rings out there, but they 1) are expensive, 2) require filing of your crank arms 3) usually require spacers (on top of the filing).

    All of these things stand out as bad qualities. To add to your excitement; you'd probably gain the same amount of clearance from 32-30, that you would from bash guard to no bash guard, maybe less.

  7. #7
    mtbr member
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    Take a look at trials bikes to see what gear you'd need.

    But it's still not a good idea - trials bikes don't get the hours of use that a mountainbike gets.
    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  8. #8
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    you will eat through chains far faster than with normal gears

  9. #9
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    So what are thr problems associated with micro drive, i have planned to run 36-12 on a surly 1x1 reason being chose profile bmx cranks and max size i xan fit on the front is 36t sprocket ?

  10. #10
    I'm just messing with you
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    Quote Originally Posted by Efff

    I question Trek's wisdom in choosing to put that decal on a bike, especially a 69er.
    Chasing bears through the woods drunk with a dull hatchet is strongly not advised

  11. #11
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    umm... you're not "getting" the point of microdrive...
    the point i to keep the same gear ratio (close to 2:1) only with smaller rings for ground clearance.
    You don't just grab the smallest cog and toss it on the same front chainring!

    36x12 is 3:1... roadie ss gearing (wife's running 42x14 to get the same 3:1 ratio)
    you need a 24 instead of your 36 if you want to keep the gearing about 2:1 (assuming you keep your 12 tooth ring there)

    granny gears can easily be found in about 24.
    profile also makes sprockets in those sizes (beefier than granny gears usually are)
    Last edited by byknuts; 07-11-2009 at 07:28 AM.
    If steel is real then aluminium is supercallafragiliniun!

  12. #12
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    You might have some luck with Tom Mayer at Mountain Tamer. I believe he's just selling down stock though, so your options will be limited. http://abundantadventures.com/quads.html

    And you could find the 74mm BCD on this crankset (Sugino XD600).

    http://www.bikeman.com/CR1031.html?u...ign=GoogleBase

    But you could skip Mountain Tamer and probably find some small 74mm bcd inner cogs on your own. Mountain tamer would be the route to find the smallest though.

    I suppose you'd need a gearer rear hub so you could move the chainline inwards.

  13. #13
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    ^ ^ ^

    going to a 74mm BCD is a great option. Otherwise you are stuck with replacing the cranks with a 104/64 4 bolt setup, a 26T inner ring, and a 13T cog in back would get you about as small as possible. 24/12 is possible also, but hard to find a 12T ss cog.

    You are probably going to want to run tensioners to keep the chain wrappped as much as possible. That's a scary low number of teeth engaging at any one time.

    Moving to a trials setup, you could run a 22T front freewheel and a 13T cog in the rear, this will give 1.7:1 which a little lower than you may want, but plenty of clearance.

    Neat idea... as many others have mentioned though, probably a little impractical on a mtb.

  14. #14
    SSolo, on your left!
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    Quote Originally Posted by wv_bob
    I question Trek's wisdom in choosing to put that decal on a bike, especially a 69er.
    ROTFLMFAO!

    Quote Originally Posted by fishcreek
    micro drive is for show bikes and non-riders.
    Yes, and it will wear out everything alot faster and may have skippiing problems as a couple others have said.
    Last edited by Natedogz; 07-13-2009 at 11:07 PM.
    Get off the couch and ride!

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