Originally Posted by
Nyimbo
I brought home my new 2013 7.7 this week. *I bought the 54cm but when I got it home I was very surprised it was about 2 inches shorter end to end than my 2010 7.5 (20inch model) *The salesman set me up on the 54cm looked like the right fit for me and it felt ok on my test ride, but when I got home and saw the difference it really confused me.
*
I always thought the old bike fit me wonderfully - not that I know much.*But I know I was always comfortable.
Anyway because of rain this week, I only rode it once for 10 miles. *I did wonder if the new madone frame and all makes it so that the bike is shorter, or did I have too big a bike last time, or do I need to go back in and try the 7.7 in the 56cm size.
Yes. This raises a pet peeve of mine (sorry!): the 'new' 7.7FX is, literally, a Madone 3-series frame with flat-bars thrown onto it. That frame was/is designed for drop, not flat, bars.
Part of the shorter wheelbase you are noticing is down to shorter chainstays; a further substantial part of it is down to the top tube being too short. The "54" 7.7 is not equivalent (for fit), with flat bars, to your 20" 7.5 re. effective t/t. If your 7.5 fits you "wonderfully", you really should try the "56" 7.7FX; that
might get you into the ballpark. The "54" 7.7 is likely way too short in effective t/t, for you.
IMHO, road bicycles that are going to be fitted with flat bars should be designed to be used with flat bars; part of that means having an effective top tube at least a couple of cms. longer than that of an equivalent frame designed for use with drop bars, for a given size, to compensate for the forward throw of the hoods on drop bars. I dislike the current trend among the big 3 (Spec, Giant, Trek) simply to market their carbon road frames as "flat-bar bikes" w/o proper modification. Conversely, Giant's aluminum Rapid is correctly designed (in relation to its Defy cousin). I understand the economics, but I don't like it. Effectively, one is always going to have to look at at least 'one size up' on these bikes, unless one wants an extremely "upright" position. E.G. I would ride a "54" Madone or Spec. Roubaix, but would need a "56" in a 7.7FX or Sirrus Limited; unfortunately, this 'sizing up' re. the latter brings compromises in other areas (head tube height, standover etc.) I would find unacceptable. YMMV.