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  1. #1
    Knolliac
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    progressive Ti springs

    Is a 2.25" Progressive Ti spring an acceptable length for a Roco TST with a 2.25" stroke? Is the 2.25" label on the spring indicating that it should be used with a 2.25" stroke shock? Or should I look into a 2.5" spring? It is listed as "Free Length: 5.25in - 133mm with a Travel of: 2.25in - 133mm". Thanks.

  2. #2
    mtbr member
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    It will work fine.

    Most springs are listed as to the shock stroke. That is a spring labeled 2.00 actually has something like 2.10 inches of total travel before bind, and is designed for a 2 inch stroke shock.

    Fox is the one that I can thik of that list the true total spring travel on some of their springs. This is why you always see fox springs with odd measurements, like 2.20, or 2.28, 2.8 etc. These are designed for a shock with a stroke less than what is listed on the spring...a confusing and bad idea IMHO.

  3. #3
    Knolliac
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    thanks! i just picked one up on ebay for $60 new.

  4. #4
    www.derbyrims.com
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    A spring's marked length number is the compression distance before coil bind. Coil bind will damage your shock and possibly more.

    You should get a coil that is at least 2.4 at the very minimum for a 2.25 stroke shock to allow for small adjustments in preload. An even longer coil would be better.

    A 2.25 coil would only work if it were never adjusted for any preload, which is a very poor match and limits the use of the bike.

    A well matched coil is set with about 2 - 3 turns preload, and preload is relaxed a turn or two for long downhill runs, and more preload can be added for occasional heavier compression use such as jump sessions.

  5. #5
    mtbr member
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    Quote Originally Posted by derby
    A spring's marked length number is the compression distance before coil bind. Coil bind will damage your shock and possibly more.

    You should get a coil that is at least 2.4 at the very minimum for a 2.25 stroke shock to allow for small adjustments in preload. An even longer coil would be better.

    A 2.25 coil would only work if it were never adjusted for any preload, which is a very poor match and limits the use of the bike.

    A well matched coil is set with about 2 - 3 turns preload, and preload is relaxed a turn or two for long downhill runs, and more preload can be added for occasional heavier compression use such as jump sessions.
    The Progressive Ti springs are labled in correspondance to the stroke of the shock they're supposed to be used on. Ditto for Marz, Manitou (I think), and pretty much everyone else. Fox is the one notable exception. They label the maximum the spring can compress before binding. While what you said is true, it's somewhat misleading due to the labeling system used by most manufacturers. In pretty much every case except Fox, a spring labeled as a 2.25 can safely be used on a 2.25 stroke shock, so long as the preload isn't excessive.


    I've got a 2.25 Progressive Ti spring on my 7.875x 2.25 Roco TST. It works well. There's no way you'd be able to get a 2.5" spring in there. The free length is much too long.

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