I would test drive them.
Certainly the Allez is available for rent in many places.
It is certainly fast.
It is not important that you test drive bikes with exactly the same gear grouping because extra gears without extra range is pointless anyway--just important that you test drive a bike with the exact same frame and same size.
One minor point on all of these bikes is that you probably need a frame that is about 1 size larger than you normally ride. Test drive. Next, you will probably want to put a shorter extension stem on it unless your hands normally swing down at your knees when you walk. That's not likely.
By replacing the "whopper" stem with a more traditional 90mm stem, the bike will last much longer. The bikes you mention have a
paper thin head tube that will start
cracking within the year. Using (
changing to) a "normal" 90mm size
stem will postpone this for a very long time.
One other element in
preserving the frame on hot-performing "weekend warrier" type bikes, is to discover how little air is required for the front tire--without affecting performance. This varies by rider weight. Just get a speedometer and try different air pressures in the front tire.
One particular front tire air range will be both more comfortable and faster. If this cannot be done, and if the frame is very rigid (aluminum) then try a Panaracer Pasela on the front 700c x 28mm (actual 26mm--Jap sizes run small). Not marketed as a race tire, but it is the fastest touring tire and will keep the frame from
cracking during your training rides, group rides, city rides, trail rides, light offroading and other enjoyment whenever it is not necessary to expose aluminum to rock hard tires.
For the least maintenance, the least number of gears on the rear of the bike will shift the fastest and require the least number of adjustments. The Sora 7 (copy of Campy Ergo) is still available from Harris Cyclery (application uses Sora 7 shifters, cassette, 7 to 8/9 cassette spacer ring, 8 speed chain and Tiagra rear derailleur), and it is compatible with high-grade 9 speed front cranksets. This group can be struck by curb, tree, bike carrier, leg, rock, etc. . .and still not go out of adjustment.
What? Well, a freshly tuned 30 speed bike could possibly outperform a 21 speed that has had no maintenence for an entire year. The reverse is not true.
I'm not advising to retrofit a new bike with an older drivetrain, unless you ride in the city, where durability is a primary concern.
Actually. . .
That was just an example of how gear grouping is totally unimportant compared to the bike frame and sizing.
Gear range is important, so I'd be sure to get the "triple" crankset for that day you've gone on a marathon and there's a huge hill at the end.
Although, a new fusion technology has breathed new life into the "road double." The wide range rear cassette has more power for sprints (hills and everywhere) and works great with the "road double /compact double". In this case (11-32 cassette), every "flap" of the right-hand lever gets more work done, and is a far more time-saving approach than 9 or 10 shifting efforts to go across a compact (12-25) cassette.
After all, if Shimano is going to make us lean over and flap a lever 9 times last year, 10 times this year, maybe 11 times next year, the wide range cassette (with compact double on front) is a great way to
combat this labor intensive trend.
What doesn't work? Compact gears on BOTH front and back does not work well (performs like a 70's mass market 10 speed). Some of the offerings in the lineups you mention have all of these combinations.
Have fun! Rent! Test drive!
