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Thread: De Rosa sizing?

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    De Rosa sizing?

    I'm a bit confused about the actual size of a De Rosa. There are a few frames selling on ebay. Can anyone explain the ACTUAL size? AFAIK, De Rosas aren't measured from center to center, rather from the top of the BB to the bottom of the seat collar?

    Actually, I might just get confused with lengthy explanations, so what would a listed 56cm De Rosa really be?

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    Senior Member DanMartin's Avatar
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    Go by the top tube measurement, whatever is closest to what you ride now.
    If not shown, have the seller send you a picture with a tape measure of the top tube.

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    DeRosa frames may have may have some oddball frames size numbers, if you're looking at a model with an integrated seatpost. The frame size can still be determined by looking at the TT length and the seat tube angle to figure the frame reach and the head tube length, to figure the vertical size of the frame. Different models have slightly different geometry, so you can't evaluate one with specifying the model.

    http://www.trialtir-usa.com/derosa/k...ing3rs-geo.htm

    http://www.trialtir-usa.com/derosa/merak/merak-geo.htm

    The DeRosa steel frames use traditional c-c frame sizing.

    http://www.trialtir-usa.com/derosa/n...rimato-geo.htm

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    The TT length is not the best thing to go by. One frame can have a 55cm TT and another a 56cm TT, but both can have the same reach, depending on the STA. You might buy the 56cm and find that it's got 1cm shorter reach than you thought.

    Also, the head tube lengths often very by twice as much as the TT length, so you could get a frame that's too tall or too short.

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    Senior Member DanMartin's Avatar
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    If it's a cm long or short in the length, wouldn't that be solved with a shorter/longer stem of 1 cm?
    Head tube length would be solved by how much the steer tube is cut.

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    Quote Originally Posted by DanMartin View Post
    If it's a cm long or short in the length, wouldn't that be solved with a shorter/longer stem of 1 cm?
    Head tube length would be solved by how much the steer tube is cut.
    You're right about the TT length, but is you get a head tube that 2cm too short, or too long, it may require a huge stack of spacers or you might not be able to get the bars low enough, if the head tube is too tall. Of course, the steering tube is not a problem, since there is usually only one length, long enough to handle any frame.

    The idea is to get the right head tube length and frame reach so you don't have a goofy looking stem setup that screams: I bought the wrong size frame.

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    Senior Member DanMartin's Avatar
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    Quote Originally Posted by DaveSSS View Post
    You're right about the TT length, but is you get a head tube that 2cm too short, or too long, it may require a huge stack of spacers or you might not be able to get the bars low enough, if the head tube is too tall. Of course, the steering tube is not a problem, since there is usually only one length, long enough to handle any frame.

    The idea is to get the right head tube length and frame reach so you don't have a goofy looking stem setup that screams: I bought the wrong size frame.
    I understand what you are saying, I just went through the same thing with De Rosa last month, and unless the OP has some weird proportions, the top tube is a good guide.
    But, buying online, better be safe than sorry getting the wrong size, because you will probably get stuck.

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    Quote Originally Posted by ndchao View Post
    I'm a bit confused about the actual size of a De Rosa. There are a few frames selling on ebay. Can anyone explain the ACTUAL size? AFAIK, De Rosas aren't measured from center to center, rather from the top of the BB to the bottom of the seat collar?

    Actually, I might just get confused with lengthy explanations, so what would a listed 56cm De Rosa really be?

    The actual seattube length is pretty much irrelevant. All that it is, is a kind of marker to tell you which frame it is in the range, so you can look up the geometry. As long as the ebay seller has said what size the bike is (52, 54, 56 etc.) then just find the geometry somewhere online or from the seller and you can start looking at the dimensions that actually matter, like the ones that the other posters have been talking about..
    Last edited by scirocco; 12-09-10 at 10:02 PM.

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