Compact v double

My cervelo has a FSA 34/50 compact crankset on it. I am currently running a 12/25 cassette on it. It is fine for normal riding, however i run it out easily on fast sprints and downhills. I have just ordered a 11-23 cassette which i hope will give it that right amount of legs for the sprints. My question is, how many guys run compact cranks or do most run doubles for racing? Most of the racing i do over here is fairly flat, with the hilly courses not very hilly at all. I want to start doing some 2 day races next year and i wonder if a double would be ok for the hilly courses mated with a 11-23. I think a 53 with a 11 on the front would be great for sprinting! Am i worth going to a double?
2009 Cervelo S1
2008 Specialized Allez Elite
2008 Specialized Allez Elite
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".... I run it(50-12)out EASILY on fast sprints...."??????? I'd join the pro tour if I were you.
At the other end a 38t small ring with a 27t sprocket would give you 37" which is almost the same as your existing 34x25t
That should get you up anything .
If you stick with your compact then get a 11t -27t cassette which will give you the spread you need .A Deore or XT MTB cassette will give you the sprockets you need just mix and match with your existing cassette. Don't forget you'll need to use the special size 11t lockring with the 11t sprocket
sorry just noticed you have already ordered the 11-23 well that will give you the increased top end you need 50x11 is about 122 " an additional 10" but you have lost 3" at the bottom end which is the equivalent of losing one gear shift
11 119.5... 81.2
12 109.5 ... 74.5
13 101.1 ... 68.7
14 93.9 ... 63.8
15 87.6 ... 59.6
17 77.3 ... 52.6
19 69.2 ... 47
21 62.6 ... 42.5
23 57.1 ... 38.8
25 52.6 ... 35.7
easier to show than explain.(This is in gear inches ) if you have a look at Sheldons site there is a niffty gear calculator there.
http://sheldonbrown.com/gears/
Well not super easy, but i mean that i get a high cadence sprint if its on the flat and i need another gear.
2008 Specialized Allez Elite
Will i need anything special to add the 11/23 compared to the 12/25 thats on there now or will i need a special lockring?
2008 Specialized Allez Elite
Knowing that I am in the lowest gear of 39-23 on a steep hill, the only thing you can do to be able to pedal at a comfortable rate is push harder (+ hence go faster), whereas on the training bike with a 36-27 lowest gear, I would simply reach for an easier gear and spin up the hill.. at lower speed.
So for racing I dont think you need a tiny gear to spin up hills since you want to keep speed high- unless hills are something you struggle with -?
2008 Specialized Allez Elite
you'll need a special 11t lockring which has a smaller dia but the right lockring will come with your 11-23 cassette .
ok thats great its included, i was hoping i wasnt goign to have to buy one. Hopefully the 11 - 23 should be a good mix with the 34/50. Looking at the rollout calculators, the 39/53 doesnt really offer that many advantages, just a closer gap between the big and little ring and a little more top end roll out. So is that the main advantage with going to a 39/53 over compact (a closer ratio between the little and big ring)?
2008 Specialized Allez Elite
I have always used 53x38 chainrings but after a 4 year layoff due to lumbar problems I have been forced to use a compact because of the excess weight I'm carrying.I have now changed both my bikes to compacts .
If you are considering raceing you must be pretty fit so the solution you have chosen is probably the best one and certainly the cheapest option.