Originally Posted by
ColtJ
Not sure we're on same page.
My TCR is a M/L which has a 57cm tt and a 17cm head tube, going to a medium (same make and model) would give me a 55.5cm tt and a 15cm head tube.
If I measure my bike from a stack and reach perspective, all I have to do is duplicate it on the smaller bike given the saddle height and setback would be the same in relation to the bb.
I only assume what length stem and know that I will run more spacers given I don't really intend to lower bars or run a different angle on stem.
Based on my height it's suggested I ride a medium or a 54 in most makes, I seem have slightly longer legs and arms than most paired with being flexible.
Other than lowering stem, I'm curious to know if there is anything to gain other than a few grams in weight. Could there be some characteristic changes/improvements that would justify the switch. That's what I'm curious about.
Im in sure I can lower bars to not run a spacer on smaller bike but I prefer running a traditional drop which allows me a higher position on tops but a low enough position on drops paired with bending elbows. Assuming I had to have a bike with no spacers for aesthetics.
In others words would there be an improvement of some sort riding a bike with a shorter top tube, shorter wheel base and head tube compared to a slightly longer top tube in terms of performance assuming I can duplicate the fit (which I'm sure I can).
I could also pose the question in reverse and ask if there would be a reason to go a size up and run a shorter stem given I can still clear the stand over requirements of a larger frame.
note: my Fixie has a 58.6cm top tube and I run a 100mm stem with track drops
Oh, I didn't realize you were talking same make/model as you already have.
In that case, I'd say no, there's probably no improvement to be had going smaller, because the elements most germane to handling are the same, e.g. head and seat tube angles, bb drop and chainstay length (talking Giant TCRs, here).
Yes, you're weight will shift forward over the front wheel some, due to shorter wheelbase, which could be positive or negative depending on where your balance is now. It sounds that you have long arms, so perhaps out of the saddle efforts might pull your weight a bit further forward, perhaps making the bike feel less stable during those times.