Originally Posted by
melikebikey35
As mentioned above...sizing by seat tube does not apply to modern frame design. Some brands don't even list seat tube measurements.
The best way to determine size, is by the stack and reach numbers. These will tell you how the bike will fit, then you can look to the other measurements (heat/seat tube angle, BB drop, rake/trail, wheelbase, etc.) to determine how the bike will feel on the road.
I do think it's save to say that the M/L you are looking at simply will not work for you. So the next step is to figure out if a TCR in a L will work, or if you need to look into other brands, or stick with the Defy that you currently have....we should start with the question, why are you looking to replace it?
I bought my Defy because it was my 1st road bike and I wasn't sure whether or not I'd like riding. Turns out that I love to, and I now want upgrade components (Carbon wheels & Ultegra DI2). Replacing it completely will be cheaper than upgrading my current one. I could always grab a Defy Advanced Pro, which is a little more expensive than the TCR Advanced Pro. Still, I need to test a TCR.
My local shop offered to let me try both (TCR M/L and TCR L Advanced lineup (non-pro)) on their training exerciser so I can have an idea on the difference. At the same time, I'll be able to see if I like the TCR geometry & if they're able to fitt me on a M/L. I might just end up buying one of their Non-Pro ones (Adv. 1), but it would be hard for me to justify upgrading my bike & spending money for another one that does not have DI2 and Carbon wheels.
I'm aware that the TCR will put me in a more aggressive racing position, and I'm comfortable with that. My back and shoulders can handle the extra stress, as long as it's fitted properly for my body. If the M/L TCR can't be fitted properly, it's not worth buying it.