Building my first bike - choosing the right components

[Woz]

+1 Couldn't get along with compacts either. There's definitely a place still for road triples.

 

[Ugo51]

The main disadvantage with an MTB chianset is that the q-factor is rather wide as it has to clear wide chainstays. Personally I try to minimise it and would go for a road triple.
Perhaps the neatest way is with a tripleiser ring, which fits on a double chainset's inner ring and takes the granny. Then nobody need know your dirty secret!

I have run a 12-23 with 30/39/48 triple with a short cage rear mech no trouble and still allowing big-big (essential to avoid wrecking the lot inadvertently). I dislike a compact as the 34T is on the small side for most duties and the jump to 48 is large.

This is a good point actually.
I had a look at the crankset again, and it's marked LC M500, so I am no longer sure whether it is the same as the 500LX, or we are talking about two different cranks. I'll measure the Q factor one of these days. I never ran that crankset on any bike, it's always been sitting in a box, so I don't know how it fits.
Otherwise, I'll get myself an older Tiagra/105 crankset (a few weeks ago there was a beautiful vintage Ultegra for sale on ebay, but I was too stingy and lost the auction...)

 

[pigman]

To those who say they cant get on with compacts, I too was like that at first, but they are ridden differently. With a standard chainset, you tend to ride on the 39 or 42 mostly and use the outer ring for fast work. With a compact, you ride the outer ring mostly and use the inner only for those meaty hills.

What puts me off standard chainsets is that modern cassettes all start with a 11 or 12 sprocket, so coupled with a 52-or 53, im carrying a couple of gears that never get used. The last time I needed something bigger than 48x12 was descending into Bourg from the Galibier

 

[Ugo51]

Oh definitely, the triple makes only sense to extend the range toward lower gears, not higher.
A 50-11 is plenty, at least for my use.
On my commuting bike I have a 46T outer, and I rarely if ever use the 46-11 combination.

 

[pigman]

What about those new super compacts, something like 44 -30?

 

[Ugo51]

Do they come also for road bikes?

 

[Woz]

What about those new super compacts, something like 44 -30?

Or what about an old triple without the big ring?

 

[Ugo51]

Or what about an old triple without the big ring?

 

[Ugo51]

Would a rear derailleur made for 7 speed cassette (specifically a RDA550) have enough lateral movement to cover the width of a 8/9 speed cassette?

 

[pigman]

Do they come also for road bikes?

they are for road bikes. Not cheap though