compact double advice

[aicabsolut]

If you get a good compact (such as DA) and FD, you should have no problems shifting between the 34 and 50. I find my FSA is finicky a lot of the time, and there's nothing I can do with my 105 FD to make it better. AND I have a 36 small ring. I just have to be mindful of where on the cassette I am when I shift.

With the MTB cassette, have you thought about a 36 small ring? You might be able to spend more time in the small ring that way and less time shifting back and forth. Plus, shifting with the 105s might be a tad easier. 36 rings are a little harder to find, though.

Also keep in mind if you want to use the same crankarms what your BCD is. Compacts are generally 110mm while 130mm is common for other cranksets.

[anakiwa]

Sounds like a good idea to me- if I had a cross bike that's exactly the gearing I'd want.

I currently have a compact on my tri-bike. It works really well. I proably can't comment on whether I have enough of the in between gears (I have a 10 spd on that bike and don't need the real easy gears so an 11-25 is great in the back for that type of riding). With only 2 rings in the front I've found I can get away with cross-chaining pretty far (the bike has bar end shifters though so I can fine tune really well).

Another thought- how you'll be riding the bike may have an affect on how well you want to fine-tune the middle gears. On my road bike I like to be able to be in exactly the right gear. On my ancient touring bike (the one I use for commuting and dirt roads- kind of like a cross bike to me) I'm not so picky- it has a triple with a really big middle ring- I spend almost all my time in that middle ring- the back has 7 speeds and quite a range. On that bike I don't mind at all that I don't have every possible gear available in the middle (I tend to meander more on that bike and my whole mindset is different).