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  1. #1
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    Dropping gears for SS, need some feedback

    I've run gears since 2007 so I need some advice on the conversion. I like running gears but they have proven to be temperamental at times. Also, I really only use 3 of the 8 gears that I have now on the street and always 1 for DJ. I'm looking for speed, riding from spot to spot, hitting a jump or stairs and covering allot of ground. I also want a good ratio for dj.

    I have a 2012 STP 26' and this is the plan so far...
    Pimplite SS rear wheel w/ pimplite hub
    Deity vendetta 3 cranks w/ Ti spindle
    Halflink chain , possibly Shadow Conspiracy ect...
    I have adjustable dropouts so no tensioner.
    The Pimplite comes with a 12t cog so I'm leaning towards 28 /12

    I've never run a micro drive so I'm wondering if it will apply well to the kind of riding I like, is this the only option for a 48 direct mount set up? And does a micro feel less positive or efficient than a larger chainring?
    Any experience is appreciated, thanks

  2. #2
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    you wan to be as close to 55 gear inch as possible as that is the magic number for a DJ bike and BMX bikes.

    so the formula is Gear Inch = wheel size X front sprocket/back cog

    so yours is 26 x 28/12 = 60.66

    I run a 25 x 12 and it equals 54.2.... i would recommend a 25 front cog if you are going to go with a 12 in the back other wise bump that to a 13 and you can run your 28 that would equal 55.9 gear inch...

    good luck!

  3. #3
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    Thanks cglasford, so 55.9 would have a little more top speed than 55.0 correct? Also, can you comment on the feel of a micro gear compared to a standard size, like 16 / 34. They seem fine for setting up but some people say they feel mushy or not as linear under hard cranking???

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    yes you are correct... the 55.9 would require a little more torque to get moving but would have a higher spin out speed.

    Really it all comes down to what you are trying to do? If you are riding park street or dirt jumps you want something you can spin quickly and get up to speed and that is about it. You aren't really pedaling that much, or I don't, when I ride trails or park its more of a flow and street you want to just accelerate in a short distance do your stunt and then you chill.
    It's not like riding a mtb single track or racing bmx or 4x... for those you would want gears or a slightly higher gear inch ratio so you don't spin out..

    I don't know about the not linear.... the gear ratio you gave should feel almost identical to what I run. I personally can tell the difference.

    what are you going to use it for? 55 is not the magic number for BMX racing or 4x...

  5. #5
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    Quote Originally Posted by cglasford View Post
    you wan to be as close to 55 gear inch as possible as that is the magic number for a DJ bike and BMX bikes. . . .
    exactly.

    and if you like to see it in chart form, Profile has it:

    Gear Inch Chart | Profile Racing

    as for microgearing, it's true that bmx racers do not use small sprockets and drivers because of the immense torque that is used during gate starts. and it might just be a tradition thing too.

    occasionally you hear BMX riders unhappy with 8t and 9t driver hubs. like here:
    Dear BMX, please stop pushing small sprockets.

    and if i remember right, 8t drivers sometimes have chain compatibility issues.

    since it seems like you like to have more speed for street riding, you would probably like 60-ish gear inches, like 25/11.

    you could count the teeth on your current setup of the three gears you use the most and then look on the chart and see what gear inches you like the most, and which one you would ride in all the time if you had to. '; )

  6. #6
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    Quote Originally Posted by cglasford View Post
    yes you are correct... the 55.9 would require a little more torque to get moving but would have a higher spin out speed.

    Really it all comes down to what you are trying to do? If you are riding park street or dirt jumps you want something you can spin quickly and get up to speed and that is about it. You aren't really pedaling that much, or I don't, when I ride trails or park its more of a flow and street you want to just accelerate in a short distance do your stunt and then you chill.
    It's not like riding a mtb single track or racing bmx or 4x... for those you would want gears or a slightly higher gear inch ratio so you don't spin out..

    I don't know about the not linear.... the gear ratio you gave should feel almost identical to what I run. I personally can tell the difference.

    what are you going to use it for? 55 is not the magic number for BMX racing or 4x...
    I def want a bmx/4x racing gear ratio... I mostly ride street and trails/DJ. I need a gear that will allow me to cover lots of ground at high speed, going from spot to spot. Im not looking for a gear that is only good for setting up before a jump or trick. I need to roll fast for distance too.
    Also, as far as linear... I don't mean the ratio itself, but the difference between running a micro gear sized sprocket vs. a standard size sprocket like a 34. I know you can achieve the same ratios with both but does the smaller version feel different???

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    I personally don't think it feels any different... and I ride my 25x12 all over town... I personally wouldn't go any higher because i'm not racing my bike and I'm not in a huge rush to get to the new spot nor do I want to give up that snappy torque when I need it for what I actually want to ride with the bike ... you dont have to go micro drive... it's more for grinding and park so you have more clearance of your BB/sprocket...

  8. #8
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    Got ya, do you spin out at all with 25/12?
    thanks for the info

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    yeah I mean I can spin out but like I said I'm not doing full out sprints on my bike... I take like 4-5 cranks and coast if i'm riding from spot to spot or I give it a quick crank or two to get going into a jump or bank...

    i've even considered going to shorter cranks to get quicker cranks in... it would be your personal preference... My buddy likes the 28x 13 better but he is running a bike with a converted rear freehub (MTB style) , I have an actual driver/bmx style hub on mine so doesn't matter to me.. i've ran both 25 x 11 and 25x12 and I like the lighter gearing... 25x12 is pretty standard on complete builds for DJ bikes

  10. #10
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    I see, sounds like I'm going to have to play around with a few options and see what works

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    Yeah for sure.. Personally if your thing is street and dj I wouldn't want a high gear inch/ratio... I wouldn't want to have to pedal super hard when I want to accelerate.. yes its great for riding around town and cruising but doesn't seem like a great fit for the actual type of riding you like to do... unless you have hulk legs...

  12. #12
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    Quote Originally Posted by *B* View Post
    . . . I really only use 3 of the 8 gears that I have now on the street and always 1 for DJ. . . . .
    Dude! Which one do you use for DJ? Do you like it? Count the teeth. Then go to the chart and figure out how that translates to the "Gear Inch" number you like.

    We can tell you what people commonly use, but we don't know what you'll like. ; )

    I have a collection of singlespeed bikes, and they're all slightly different gearing. One of them is 25/9 with 24" wheels which is 66.6 gear inches. It hauls ass around town. At the skatepark, I like it also because with fakie rollbacks, the cranks turn slower.

    On the other hand, I have a singlespeed DJ that I use as an xc trail bike, and I have 33/16 on it, which is 53.6. That is spinnier than the "stock"/normal BMX 55 gear inches, but slighly stouter than typical xc single speed bikes that use a 2:1 ratio (only 52 gear inches). I hate 52 gear inches for cranking around town. So slow and spinny!

    So, you get it, right? The higher the gear inch number (55+), the "stouter" the ratio is.

    Your idea of 28/12 would be 60.6 gear inches. It'll be stouter than average, but still totally doable.

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