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  1. #1
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    16" bike gear ratios

    What are you running on your kids' (4 yo) 16" bikes? I have an 18t freewheel on the way, but I have a 34t chainring and think that might be a little too big.

    He has a 16" Hotrock. It currently has 95mm cranks but I have 135mm Sinz cranks to install. We ride rooty trails with a little bit of short (kind of steep) climbing. He has not mastered standing and climbing yet, but the 16" wheels are a huge improvement over the 12"!
    Last edited by mtbjen; 03-11-2013 at 08:39 AM.
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  2. #2
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    OK, doing my own calculations, the gain ratio with the current 95mm cranks and 28x18 gearing (I think) is 3.32. Going to 135mm cranks and 34x18 would yield 2.8 gain ratio, which is an improvement...

    Now, the question is, will a 16" Hotrock actually FIT 135mm cranks with a 68x113 BB?
    Last edited by mtbjen; 03-11-2013 at 08:53 AM.
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  3. #3
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    My daughter just turned 4 and has been riding her Spawn 16" for about 6 months. She is getting stronger, but I wanted her to learn how to climb on the trail. So I put a 24t chainring on it with a 24t sprocket on the rear. Needless to say it helped
    Attached Thumbnails Attached Thumbnails 16" bike gear ratios-alaura-banshee.jpg  


  4. #4
    GMF
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    Honestly, i think a 34/18 is a tall combo. I swapped out the chainring on my kids bike to a... 24? (something mid 20s) and I think an 18t cog. Stock short cranks. She isn't super fast but she can actually get the bike moving. She is now a petite 5yo.

  5. #5
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    Yes 135 will fit until they corner with the inside foot down. If you fit 18" or 20" forks you might get away with it, but you'd be safer with 115 or 120.
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