A drivetrain (chain, gears) with only 1 gear or chainring in the front and no front derailleur or front shifter. For years the norm for mountain bikes was 3x9, or 27 gears. The front of the drivetrain had 3 chainrings and the back had 9 gears on the cassette. To shift between all the gears, a front and rear shifter and derailleur was required. The industry went to 2x10 and now 1x10, 11 or 12.
1x is mechanically simpler, less to go wrong and lighter. Most new bikes will have a 1x setup, but older bikes can be converted. Conversion information and costs are in the "How To's" below.
Quite simply, not having tubes in your tires, just like car tires.
The Pros: less weight, increased traction due to running lower pressures, no pinch flats
The Cons: sidewall cuts can call for a new tire, not all rim/tires and be converted
Checkout the Tubeless How-To below.
This one always gets people. Clipless pedals are actually pedals you clip into. Yes, I know!
In the olden days, when you wanted a secure way of keeping your foot/shoe on the pedals you used toe clips. Well, when the industry developed spring loaded clamp pedals that grab onto a cleat on the bottom of your riding shoes, they dubbed them "clipless" since they were sans the toe clip.
Fast-forward and we still call them clipless pedals.
A derailleur hanger is a sacrificial part attached to the rear of the bike frame. The rear derailleur mounts to the derailleur hanger, which in turn mounts to the frame.
This part is sacrificial because in the event of a crash the hanger can bend or break and usually the frame is undamaged. The hanger can easily be replaced and we often carry a spare in our tool/parts kit. Bent hangers can be fixed with special alignment tools, but usually only once, as the metal becomes weak from the bending.
Before hangers, frames were often damaged if the rear axle area took a hit. This damage required frame pullers, benders, etc. and more time, effort and cost to repair.
So, we recommend that you get a spare hanger for your particular bike/frame. The hanger design is specific to your frame, so it is best to consult your bike shop. However, if you are fairly knowledgeable about your frame, model, year, etc. you can order a replacement hanger from the manufacturer’s website or third party vendors, such as deraillerhanger.com. Spares range from $10 to $50, depending on the bike.