With our new configurator, you can specify which crankset and chainring set you want on your bike. While adding a lot of flexibility and customization for the rider, it can also lead to a lot of confusion if you aren't sure what to choose. So let us help you out!
We build our bikes with Full Speed Ahead cranksets for a couple of reasons. First, they make great cranksets! They are reasonably priced, good looking, and use a 30mm axle for better power transfer. But why choose the SL-K over the Gossamer?
The SL-K Light crankset is a hollow carbon fiber structure that is stiff and saves weight over the Gossamer (653g vs 760g). This model also uses stiffer chainrings for better shifting under load. The Gossamer Pro, however, is no slouch. It uses a forged aluminum arm and good quality chainrings for reliable shifting. Both use a 30mm axle to reduce flex and provide better power transfer.
Each crankset is offered with three chainring combinations - 39/53t, 34/50t and 30/46t. The first two are pretty standard offerings in the bike world, but the last is a newer entry and designed for gravel bikes that need lower gearing.
To choose, consider the kinds of riding you are doing. Are you spending a lot of time climbing? Then the lowest gears of the 30/46t would be best for you. Are you riding the flat lands of Florida? The standard 39/53t will be great. Not sure? You can go the middle ground with the 34/50. Our recommendation is to always err on the side of lower gearing.
Now I know some of you that have been riding are going to ask "Don't I need a triple to get a full range of gears?" With the advent of more speeds and wide range cassettes, the triple crankset is just no longer needed. A double crankset gives better shifting and less confusion about gear selection. For you gearheads, here are some numbers to think about:
Your previous bike had a 9s 11-32t cassette and a standard 30/39/52t crankset. Your gear range was 24.7" to 124.7". What does this mean? In your lowest gear, climbing a steep hill at 60rpm, you would be traveling at 4.4mph. In your highest gear, descending at 100rpm, you would be traveling at 37.1mph.
With your new set up with an 11s 11-42t cassette and a 34/50t crankset, your range would be 21.4" to 119.9". This translates to 3.8mph at 60rpm and 35.7mph at 100rpm. As you can see, your top end doesn't really suffer, but you get lower gearing. And you can get even lower going with the 30/46t chainring set! (we use the Sheldon Brown Gear Range Calculator)
I hope this explanation helps. In a different post, we talk about cassette selection, as this can definitely influence chainring selection. But for now, the general rule above applies.