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  1. #1
    transport, not sport.
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    20t chainring, who needs 'em? I do!

    right after i got myself a rigid steel 29er, some folks here who are not so familiar with 29ers, would comment: "this thing is heavy to ride uphill!"
    they might have misunderstood. maybe it is heavy, when equipped with the gearing of 26" wheel, since 29er has bigger diameter than 26.
    so i searched the net, and found some nice threads about low gearing for 29ers.
    i am aware that one option is to get the 11-36t cassette sprockets.
    but i am a cheapskate. so i looked the other way. i looked at the option of putting a smaller chainring.
    at the local market, someone is selling new old stock 42-32-20 crankset. $40. but still it's expensive for me.
    and then i found a thread of 20t chainring conversion.
    wow. stambeco mountain goat 20t. actiontec. still expensive.
    so i decided to make my own.
    took a $1 20t steel cog. ground the teeth manually to make it thinner to accomodate 8sp chain. drilled 4holes bcd64(?). and put that on my existing $20 FSA crankset, replacing the 22t.
    there were some more grinding of the spider to give more chain clearence, just like it was explained in the 'stambeco 20t chainring conversion' thread.
    voila! now i have low gearing of 17 gear inch. 20t chainring with the 34t sprocket.
    17 gear inch on my rigid steel singular swift.
    thank you all for your inspirations on the internet!

  2. #2
    Senior Member Dilberto's Avatar
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    You just fitted gearing slower than you can walk the bike!
    2001 Cannondale Bad Boy Ultra - 19.8lbs/8.98kg
    2012 Trek Superfly 100 Pro - 23.6lbs/10.70kg

  3. #3
    Bad Company dminor's Avatar
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    Love hearing stories of shade-tree fabs and mods. Way to improvise, tkw

  4. #4
    Senior Member 009jim's Avatar
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    My second bike has a chain-ring of equal size to the granny sprocket on the rear cluster. I'm finding I like that more lately. I am in a hilly area and it means I can ride up the hills rather than walk. Walking hurts my ankle so, yeah, I like it!

  5. #5
    Junior Member
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    Good thread - I'm wondering about 26 vs 29 just for the lower resulting gearing on the 26. I'm in no hurry and have steep climbs.

  6. #6
    Bicyclerider4life
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    20 tooth?!? Heck, I want an 18 tooth crank ring for my touring mountain bike conversion/upgrade. It might be "slower than I can walk" but I don't like walking up hills and I'll be pulling a trailer.
    "Whenever I see an adult riding a bicycle, I know there is hope for mankind." (H. G. Wells)

  7. #7
    transport, not sport.
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    after several months with this setup,
    I think I'd write a quick review.
    the diy 20t chainring is doing just fine.
    on some hilly trails, it just feels good to have a
    34t biggest cog as bail out.
    combined with one dollar non indexed thumbshifters
    positioned under the bar,
    i am just fine.
    yeah, people may search and eventually find out that my
    frameset's pricelist is 475gbp. (they don't necessarily have to know for how much i got it second hand.)
    but i feel comfortable with the cheap parts on it.
    at least i know it's reliability..
    cheers!!

  8. #8
    Senior Member osco53's Avatar
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    Good mod work,
    same low gearing if U would have swapped the 11-34 cassette to 12-36, cost about $69 and no work.
    Scott Spark 760, Tour Easy LE, Sun EZ-3 sx, Walmart Thruster :P

  9. #9
    transport, not sport.
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    forgot to add.
    i decided to remove the 42t outer chainring.
    replaced with a used $10 fsa gravity bashguard.
    so, my bike is 2x8 now.

  10. #10
    transport, not sport.
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    Quote Originally Posted by osco53 View Post
    Good mod work,
    same low gearing if U would have swapped the 11-34 cassette to 12-36, cost about $69 and no work.
    you are right osco53!
    but for me, $69 is something
    while the one dollar 20t cog-into-chainring costs me almost nothing.

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