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  1. #1
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    Question about altering frame geometry via different forks.

    Ok, so I figured you guys would have the most knowledge in this subforum about this, being that you make your own frames and all.

    I'm in the process of building up the old lady a bike, which is a 2001 Gary Fisher Napa size small. I went with this frame, because #1 its free, #2 she needs a smaller frame, #3 when stripped and polished, matches my bike which is debadged Ti.

    So this bike is a comfort/commuter frame, however it seems to be pretty beefy, and more of a MTB type frame. Please note: She does not need a full on MTB, this will be a towpath and rail trail type bike.

    Anyways, my questions are centered around this:

    The bike came with a rigid fork, and I recently picked up a Rockshox 80mm suspension fork for it, however the forks dropout is roughly 1.5 inches longer, and further back than the original rigid one.

    Obviously, we are talking about a small difference in geometry by swapping to this fork. Which pops a few questions in my head.

    #1 Will this change in any way effect the durability of the frame?
    #2 Will this bike be rideable and comfortable still, It looks like the footprint of the wheels will be closer together.
    #3 Is this even worth building, or should I look to find her another frame?

    Thanks!

    And heres a link to the bike/frame in question, just incase.
    2001 Gary Fisher Napa - BikePedia
    Last edited by steveohio; 02-07-2014 at 10:43 AM. Reason: added link

  2. #2
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    if it were me, i'd look for an actual mountain bike frame instead of a purpose built commuter/townie. The link doesn't have the geometry so it's hard to tell how it'll exactly change the geometry of the bike, but i don't think it'll be for the better.
    The biggest concern for me would be that the downtube and head tube were not meant to handle a suspension fork no matter what the travel. It's probably fine being thicker tubing, maybe even straight gauge but taking it off trail with the suspension fork would put more stress on the weak links and maybe make it fail/break. If it's just a rail trail cruiser that won't be ridden hard, it'll probably be fine if you just want to add some cush to the front end. The knobs on the fork may not clear the downtube either, so watch for that too.
    But i'm sure that you could find an nicely used mtb on CG or ebay that would be a better bike all around.

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