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  1. #1
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    fork rake question-

    About 3 years ago, as a fixed gear kid, I bought and built up a Dolan Precursa. I opted for the road fork option because I was running a front brake. Well it has been sitting around since then and now that I have gotten more into road racing I figured I could put my Dolan on the track with a few modifications. Basically, will the road fork be a problem for at least a few races before deciding on my track racing future or is it a definite no?

  2. #2
    Senior Member Kayce's Avatar
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    What track will you be at?
    If You Meet The Buddha On The Road, Kill Him

  3. #3
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    Quote Originally Posted by Kayce View Post
    What track will you be at?
    Trexelertown- 333m, 28degree bank, concrete

  4. #4
    aka mattio queerpunk's Avatar
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    It depends on the head tube angle of your frame, and the rake of the "road" fork they sent you. Look those up and post 'em here so that we can tell you that no, it won't be a problem for your first races.
    the hipster myth.

    i practice vagabondery.

  5. #5
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    Quote Originally Posted by queerpunk View Post
    It depends on the head tube angle of your frame, and the rake of the "road" fork they sent you. Look those up and post 'em here so that we can tell you that no, it won't be a problem for your first races.
    43mm fork rake and head angle is 73

  6. #6
    Senior Member Kayce's Avatar
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    For your first 3-4 years it will never be an issue. It MAY become an issue when you get to a Cat 1-2 level.
    If You Meet The Buddha On The Road, Kill Him

  7. #7
    Senior Member theblackbullet's Avatar
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    I raced the entire season last year at the Dick Lane Velodrome on a road fork with no issues. I even made it up to the velodrome in Rock Hill, South Carolina one weekend and had no issues on their much shorter/steeper track.

  8. #8
    aka mattio queerpunk's Avatar
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    73/43 comes to a trail of 5.9, which is perfectly reasonable for track bikes.
    the hipster myth.

    i practice vagabondery.

  9. #9
    Brown Bear, Sqrl Hunter Jaytron's Avatar
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    Is there any place I can read about trail and how it affects track bike handling? Also, how is trail calculated with the HT angle/rake?
    PedalRoom

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    follow me maybe.

  10. #10
    Decrepit Member Scooper's Avatar
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    Quote Originally Posted by Jaytron View Post
    Is there any place I can read about trail and how it affects track bike handling? Also, how is trail calculated with the HT angle/rake?
    Two excellent places to start are ex-framebuilder Dave Moulton's blog articles, Head Angles and Steering and Trail, fork rake, and a little bit of history.

    The formulas for determining trail for a given fork rake and for determining fork rake to get a given trail are:



    It's easiest to use a scientific calculator with trig functions, but if you don't want to mess with the math use the on-line version of BikeCAD. You can play around with different wheel (rim and tire) sizes, head tube angles, and fork rakes to see what trail the different combinations will produce.

    Examples:

    Last edited by Scooper; 03-20-13 at 11:24 AM.
    - Stan

  11. #11
    aka mattio queerpunk's Avatar
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    Don Walker's The Truth About Track Bike Geometry is good, too.
    the hipster myth.

    i practice vagabondery.

  12. #12
    Decrepit Member Scooper's Avatar
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    Quote Originally Posted by queerpunk View Post
    Don Walker's The Truth About Track Bike Geometry is good, too.
    Excellent. Thanks for the link.
    - Stan

  13. #13
    Senior Member chas58's Avatar
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    Probably not a problem on that track, but I put a road fork on a bike once (increasing offset by 5mm) and it made the bike pretty squirrly on a short steep track. Worked fine on there road, probably made the bike more responsive, but was a handful on the short track. Mild 333m track, probably OK (assuming it rode fine on the road). But if you take up the sport, get the bike back to spec as soon as you can.

  14. #14
    Senior Member chas58's Avatar
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    One more thing:

    road forks are not designed to take the extreme side loading you get on a track. People around here pull 3-4G's on a track while moving up/down track, and good ones can sprint out of the saddle at those G forces. Probably not an immediate concern for you on a 28 degree track, but something to keep in mind for the long term.

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