Originally Posted by
scirocco
Sure, so if you don't like that "leverage" combination, just change up or down one or two at the rear. The whole idea that the leverage depends only on the front rings is nonsense - you can't take it in isolation to the rear.
All that the compact gearing can give you is a different spread of ratios, packed a little closer at the botom end rather than at the top.
But if you need larger than a 50/11, you don't have an option to go to a smaller cog in the back.
And you can put a 52 chainring on a 110bcd crank, but if you don't need a 34 inner chainring there's just no reason to ride a compact.
And here's the dirty little secret: the climbs in France are not that steep. The HC climbs rarely have sustained sections over 10%. They are very lng but not tremendously steep. Some of the Category 1 and 2 climbs are steeper but not for long sections.
I'm a Cat 4 Clydesdale, and I can climb L'Alpe de Huez, Mt Ventoux, Col de Galibier, Col De Aubsique, Col de Izoard amongst others on standard gearing.
My bet is the lead guys aren't actually using below a 39/23 very often.
These guys are climbing well above 10 mph. 39/27 at 80 rpm is 9.3 mph. They just don't need smaller chainrings for the TDF.