Compact Cranks
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Compact Cranks

Compact cranks use a 110mm spider to accommodate a smaller inner chainring.  This allows you to gear almost as low as you would using a triple with a 30-tooth inside chainring.  The 34-28 combination allowed by SRAM's 11-12-13-14-15-17-19-22-25-28 cassette is very similar to a 30-25 with a triple crankset.  The compact crank typically comes in a 50-36 or 50-34 combination.  

The 33

TA makes a 33 tooth chainring that will gear you even lower with a compact (see chart).  In our experience, it doesn't have much effect on the upshift, even with the 17-tooth jump, which is just outside the parameter set by front derailleur manufacturers.  Two of our demo Lynskeys use 33-tooth inner chainrings.

Compare high and low gears with your typical double or triple in the following chart: 

Gear Roll-Out (inches)
50 36 34 33 53 52 39 30
11 119.5 86.0 81.2 78.8 126.6 124.2 93.2 71.7 11
12 109.5 78.8 74.5 72.3 116.1 113.9 85.4 65.7 12
13 101.1 72.8 68.7 66.7 107.1 105.1 78.8 60.6 13
14 93.9 67.6 63.8 61.9 99.5 97.6 73.2 56.3 14
15 87.6 63.1 59.6 57.8 92.9 91.1 68.3 52.6 15
16 82.1 59.1 55.8 54.2 87.1 85.4 64.1 49.3 16
17 77.3 55.7 52.6 51.0 81.9 80.4 60.3 46.4 17
19 69.2 49.8 47.0 45.5 73.3 71.9 53.9 41.5 19
21 62.6 45.1 42.5 41.3 66.3 65.1 48.8 37.5 21
22 59.7 43.0 40.6 39.4 63.3 62.1 46.6 35.8 22
23 57.1 41.1 38.8 37.7 60.6 59.4 44.6 34.3 23
24 54.8 39.4 37.2 36.1 58.0 56.9 42.7 32.9 24
25 53.5 38.5 36.4 34.7 56.8 54.7 41.0 31.5 25
26 50.5 36.4 34.4 33.4 53.6 52.6 39.4 30.3 26
27 48.7 35.0 33.1 32.1 51.6 50.6 38.0 29.2 27
28 46.9 33.8 31.9 31.0 49.7 48.8 36.6 28.2 28

The Bike Center can:

Upgrade your current system to a compact crankset
Order you a complete bike that comes stock with compact cranks
Build you a custom Lynskey with compact cranks

FAQs about compact:

How well will a 50-34 work?  Since compact cranks became a real force in the market, component companies have improved their front shifting systems to accommodate the 16-tooth jump, or even a 17-tooth jump if you want to use a 33 on the inside.  
Can I get a compact version of my favorite cranks?  Almost every popular crank model now has a compact version.
Is the compact viable for racing?  Division I pros are using compact cranks in the mountains in major stage races in Europe.  If the pros can successfully use a compact for racing, so can you.  If you feel undergeared with a 50-34, try a 52-36 or 52-38.