One of the most common questions we field when discussing gravel bikes is drivetrain configuration. The quintessential question being whether to run a “one by” or “two by.” For simplicity sake we are only going to cover the most relevant versions. In this blog post we examine the details of each to help you figure out which one is right for you.
1X Options
The first thing to know about 1x setups is that there are a few different types. You will have your choice of 11 or 12 speed drivetrains.
- Shimano has a 1×11 GRX groupset that has a cassette that ranges from 11 to 42 teeth.
- The equivalent groupset from Sram runs a 10 to 42 tooth cassette, thus giving it slightly more range.
- The most exciting and widest ranging 1x setup is the “wireless mullet.” This pairs 12 speed wireless Sram road shifters to a 12 speed wireless mountain derailleur. This allows for the use of a massive 10-50 tooth cassette (the same one found on mountain bikes.)
2X Options
For a long time gravel cyclists were stuck with gearing that was designed for road bikes. Thankfully gravel riding has pushed manufacturers to offer to gearing suited to winching up steep, back roads.
- Shimano’s all new GRX is available with a 48-31 or 46-30 crankset paired to an 11-34 cassette.
- Sram also offers a myriad of 2X options. For 12 speed your options are Red or Force AXS. Red, Force, and Rival are the mechanical variations.
Let’s Talk Climbing
Climbing is never easy, particularly west of Boulder. Many people are worried that giving up the front derailleur also means giving up giving up gear range. Most 1×11 drivetrains offer the same gear ratio for climbing as their 2x counterparts. Where a 1×11 falls short is top end speed. Typically you would be “spun out” just shy of 30mph.
1X Pros
- Less Maintenance: No front derailleur means one less moving part to keep functioning
- Simplified Experience: One less thing to think about while piloting your bike through the world
- Less Weight: Less chainrings and less derailleurs= lighter
- Sram 1×12 allows for greater range than most 2X options
1X Cons
- Decreased Top End Speed: Only true if using a 1X11
- Bigger Gaps Between Gears: The jumps between each gear are bigger making it harder to find “the perfect gear”
2X Pros
- Wide Gear Range with No Compromises: WIth a 2X you can have a wide gear range AND close steps.
2X Cons
- More maintenance: The front derailleur will require just as much care as the rear
- Heavier: More chainring and more derailleurs= Heavier
The truth is that you should try to demo both to see which one best meets your needs!