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  1. #1
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    Gan RS Sizing Question

    I've just dropped a deposit on an Gan RS Ultegra Di2. Where I live delivery will be in Feb next year, but I have a concern about the recommended size.

    Currently I ride a 2013 Giant TCR Advanced SL Rabobank in size L, comparing the geometry, I thought that the Gan in size 57.5 should be a similar fit, however my LBS has recommended 55.

    Unfortunately I can't try out the size, as being a tall foreigner (compared to the locals), they have to special order in any size over 51.5.

    Should I be concerned? I've gone with the LBS recommendation, but I still have a concern that it might be too small.

    I'm 184cm with 85cm inseam, if that helps.

  2. #2
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    How about if you post the geometries of the bikes and sizes? Otherwise, to compare I have to google them all.

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  4. #4
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    Reach and Stack are what you need to match up.
    The rest of the numbers don't matter to you now.

    587 and 401 for the Giant it seems.

    Looks like the bike shop is screwing you over.
    You are right, you should be getting the 57.5.
    I would NOT let them order you a 55, they are morons.
    use a torque wrench

  5. #5
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    Quote Originally Posted by MMsRepBike View Post
    Reach and Stack are what you need to match up.
    The rest of the numbers don't matter to you now.

    587 and 401 for the Giant it seems.

    Looks like the bike shop is screwing you over.
    You are right, you should be getting the 57.5.
    I would NOT let them order you a 55, they are morons.
    That's why I mentioned 57.5 seemed a closer match to my inexperienced eyes. I realise it won't be exactly the same, but thought it should be similar.

    Interestingly I contacted the local importer, and they claim 54 is correct for my height, very confusing.

  6. #6
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    Okay, I looked them up. ;)

    The Giant size Large size 55.5 (to make sure it's the right bike)
    effective TT=58.5, HT=18.5.

    Stack and Reach for Giant are not published. But stack is probably about like the Gan size 57.5. Reach may or may not be similar. Possibly slightly shorter since the HTA is more slack. (This is without doing the math, which I might get around to later).

    Gan size 57.5:
    TT - 575, HT=184, Stack=590, Reach = 395.

    This bike (57.5) has a shorter top tube, similar stack or overall front end height to the Giant.

    Gan size 59.5
    TT= 587, HT = 210, Stack = 609, Reach = 395.

    Top tube is about the same as the Giant, but is slightly taller. The reach for both Gans are the same at 395.

    So, the Gan 57.5 and 59.5 are different in the front end heights, but overall reach is identical. This assumes the reach is not unexpected on the Giant. It probably isn't, based on its head tube height. But I use reach as a tie-breaker when deciding between close sizes.


    Now, the 55 they recommended. TT= 557, HT=163, Stack=575, Reach =390. This is shorter than the other Gans and the Giants. In fact, by 2.8 cm's. HT also 2 cm shorter. Stack is much shorter than both Gans I've already covered, though the Reach is only half a cm shorter, probably because the head tube angle is slacker in proportion to the other numbers compared to other Gan sizes (both the 55 and the size below have the same HTA).

    Recommendation: The Giant you are riding has a HTA of 73 degrees @ an overall length of 585. the Gan 57.5 has a TT of 575, and HTA of 73.8 degrees. Since it is steeper, I infer that the reach is .8 degrees longer than that 575, or about a centimeter. Meaning, the reaches are probably the same.

    We know the reaches of the 595 and 575 Gans are the same, but that the 595 is taller.

    So, if the stem on the Giant is a good length (not overly short or long), get the 57.5. If the stem is very long (130ish) get the 595. If you want to sit up a little more, get the 595.

    Don't get the 55, it's too small unless you have a tiny stem on the Giant because it's too big.
    Last edited by aureliajulia; 10-21-2015 at 05:04 PM.

  7. #7
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    Just saw the chart you posted. Reach for your Giant appears to be 395, stack 590. So, identical to the GAN 57.5.
    Last edited by aureliajulia; 10-21-2015 at 07:22 AM.

  8. #8
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    Stem on my Giant is 130mm, but it could do with being 10mm shorter.

    It looks like this

    Gan RS Sizing Question-uploadfromtaptalk1445437720139.jpg

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    So you have a bunch spacers under your stem now?

    Well maybe a 59.5 then. Makes the shop recommendation look even more moronic.

    Maybe it's best if you get your money back and spend it elsewhere.
    use a torque wrench

  10. #10
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    Do you mean you need a stem that is 120? That still sounds like the 59.5 would work since the reach is the same. 120 is standard for my size Pinarello, not sure about the big sizes as I ride a 51.5 Pinarello. (I have a 110 mm stem. Height 170, inseam 84.75). They are designed to be used with long stems due to weight distribution.

    You are a little over 6 feet tall, most of the people I know who are that height ride a 60 cm bike.

    I always feel less powerful on a bike that is too small, though people claim it's faster due to HT height. Just don't agree.
    Last edited by aureliajulia; 10-21-2015 at 10:03 AM.

  11. #11
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    My inseam is 85.09cm, so not too far away, but obviously I'm a bit longer up top than yourself.

    I don't mind having a slightly less aggressive position on the bike, I'm not quite as flexible as I used to be ;-)

    Thanks, I'll go back to the LBS at the weekend and sort it out with a 57.5 frame size. I do suspect part of the problem is they are not used to dealing with taller people here (Bangkok).

  12. #12
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    I'd go with the 59.5 if I were you, it'll be a better fit. A touch shorter than your current bike but taller. You'll be able to have less spacers and use the same size stem most likely from the sounds of it.

    395r 609s is the 59.5
    401r 587s is your current bike
    current bike appears to have about 35mm of space between head tube and stem
    current bike owner doesn't want it any more aggressive, less if anything
    current bike is too short in the stack department
    395r 590s is the 57.5
    that will leave you using the same amount of spacers as you have now, not good for maybe wanting something less aggressive if anything.
    use a torque wrench

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    Ditto. The 59.5 is the same reach, but a bit more upright. I'd get that one, too.

  14. #14
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    Thanks both

  15. #15
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    I misspoke earlier, and changed it, but should clarify. The longer top tube by 2 cm (595 vs 575), would need a shorter stem by two cm's unless the 595 were taller in the ht, which it is. A higher head tube brings the bars closer to the rider. You should end up with little difference in stem length, unless the current stem needs to be shorter by 1 cm, but that is a separate issue.

    Btw, love the bike you chose. Just amazing! I'm on a 2012 Pinarello Quattro, and while it's a great bike, it's not in the same league as what you are getting. Congrats!

  16. #16
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    Gan RS Sizing Question

    I decided to check my old bike, a 58 Cervelo S5 that I sold 2 years ago as well, although I felt it was a little too big. You're both right, the 595 is the closest match and is right in between the S5 and TCR in terms of stack and reach.

    Very much appreciate the help.

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    Managed to pop to the shop during my lunch break, they agreed that 550 is too small, unfortunately the 595 isn't available even on special order here, so I've gone with the 575.

    Thanks again for all the help and advice, I've learned a lot!

  18. #18
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    Quote Originally Posted by moonoi View Post
    Managed to pop to the shop during my lunch break, they agreed that 550 is too small, unfortunately the 595 isn't available even on special order here, so I've gone with the 575.

    Thanks again for all the help and advice, I've learned a lot!
    There is no way for the local distributer to get a special order from Pinarello?

  19. #19
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    Gan RS Sizing Question

    Quote Originally Posted by aureliajulia View Post
    There is no way for the local distributer to get a special order from Pinarello?
    Apparently not, I did talk with the local distributor as well, and they confirmed it. I have a suspicion though they could, but they are worried they might end up with a frame size they can't sell easily if I don't take it for any reason.

    Still, worst case is the fit is the same as my TCR, which is fine. It should be a little more upright though given the reach is a little shorter, if using the same length stem.

  20. #20
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    What a shame.

    Like I said before, you should have taken your money elsewhere.
    use a torque wrench

  21. #21
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    What percentage was your deposit?

  22. #22
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    They all source from the same distributor, so would have had the same problem elsewhere, and I'd have lost my deposit ($300USD), we don't have the same consumer protection laws here as in the western world :-)

  23. #23
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    That is too much to spend on a bike that does not fit.
    Is there no way you can try an F8? They are similar geometry.

  24. #24
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    Same problem, don't bring in the large sizes.

    I spent more on my TCR, and it seems I learnt in this thread that it is also too small, but I certainly didn't notice in riding it.

  25. #25
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    Buy the fan from bellatisport

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