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  1. #1
    spunky
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    Polo/Track Geometry on small frame with 650c

    Hello!

    My polo bike has been on its last legs (small crack near seat stay) for some time. Fortunately a friend found a beaten up 49cm Soma Rush and gave it to me to build-up. It's literally just the frame and everyone I play with is having a field day explaining what I should do with it and why. The problem is that a lot of this discussion is over my head. I've taken it to the lbs in my town to ask their advice and was told they don't deal much with "the track trend."
    I rode on a friend's fixed gear (iro?) for a bit and didn't mind the "zippy" feel of it, but I distinctly remember the toe-overlap was pretty extreme. That would be nothing short of a death-trap in polo. I've sent an email to Soma, but I thought I would ask for a general opinion here too. (Thank you!) Here is a link to the geometry for the frame (http://www.somafab.com/geometry03.html). I'd like to put a 650c wheel up front. I do ride with 165mm cranks, clipped in and front/rear brakes. I've contacted a nearby frame builder about a custom fork for the build as well. Everyone seems in support of the 650 wheel, but I've pulled up a lot of conflicting opinions about how it will ruin the bike's handling. I know polo is a different sort of beast in that regard, but am I going about this all wrong?

    Any help/advice is really appreciated! I'm excited at the idea of an upgrade and just want to make sure I fully understand my options....and their consequences. :)

    Jessie

  2. #2
    Noob. longjohns's Avatar
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    running a 650 up front will drop the front end down an inch. making the bikes geometry even more twitchy.

  3. #3
    I just wanna ride stryper's Avatar
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    Quote Originally Posted by longjohns View Post
    running a 650 up front will drop the front end down an inch. making the bikes geometry even more twitchy.
    couldn't they just run a 650 in the rear too? it would keep the geometry the same and solve their toe overlap issue. It would lower the bb to the ground, but pedal strike isn't an issue in polo.

  4. #4
    spunky
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    I assumed twitchy was the same as more responsive? Polo has a lot of sharp turns at slow speeds, so would this make the bike more nimble? I suggested the 650 front and back, but was told having a 700 in back would let me gain a lot more speed.

  5. #5
    Noob. longjohns's Avatar
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    Speed depends on gearing. You could run a 650 in the rear and still have the same "speed" as a 700c with the appropriate gearing.

  6. #6
    u________u jessesv's Avatar
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    Quote Originally Posted by longjohns View Post
    Speed depends on gearing. You could run a 650 in the rear and still have the same "speed" as a 700c with the appropriate gearing.
    Yeah, moving from 700c to 650c, you'll subtract about a half inch from your gain ratio. So you'll probably need to size your cog down one tooth or size up a couple teeth in your chainring.

  7. #7
    sqrl misskaz's Avatar
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    I've got a Fuji Classic Track 43cm with 650c wheels. The 43 cm frame is made for them, and I don't play polo so take this with a grain of salt... But if you want my experience, I will say that I love not having to worry about toe overlap. My other bikes with 700c wheels all have toe overlap to some degree. I can make really tight turns on the Fuji with no worries. I have the stock chainring and cog (46/15 for a GI of 76ish inches) and it feels pretty fast to me. The specs/geometry are on the website if you want to compare the geo to the Soma frame you've got: Fuji Classic Track

  8. #8
    :)
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    Quote Originally Posted by Santaria View Post
    because physics has more street cred than tarckstars.

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