First time rack owner , or long time owner, this link will help answer many of your rack questions.
1) Do I need Crossbars to carry my gear?
Not necessarily but it depends on what you are carrying. Most of our products attach to crossbars. No gear mount can attach to the factory side rails running front to back on the vehicle.
You can mount bikes behind the vehicle on either a hitch, a trunk rack or spare tire rack.
There's a product called the EasyTop which can carry Skis, Snowboards, Kayaks, and Surfboards.
2) What does Yakima call the parts that attach to the roof?
There are at least 2 and sometimes 3 things needed for create a base rack system: Crossbars, Towers, and in some cases, Clips or Landing Pads
The Crossbars are the support bar that goes horizontally across the vehicle:
The Tower has all of the moving pieces of the system. It goes between the bar and the vehicle:
Lastly we will have the Clip, or Landing Pad. These parts are more vehicle specific and interface directly with the vehicle.
3)How does your system attach to my roof?
1- a set of clips over the doors which attach towers mounted with a cross bar to the roof. The current system is the BaseLine system
2- raised side rails, that is those in which you can put your hand between the rail and the roof . The current system is the TimberLine system which uses a stainless steel strap.
3- flush rails, that is those in which the rail is in contact with the roof it's entire length. The current system is the Ridgeline system which uses specific clips
4- fixed point, that is a vehicle roof with factory installed mounting points. The current system is our Skyline tower which will mount to the roof by one of our specific Landing Pads.
5- rain gutters, rare these days but we still have our 1A Raingutter tower, our oldest tower which unlike all the above can only work with round bars
4)What can I carry on my car?
The distance between the crossbars, measured from like points (front to front, rear to rear) will determine what products can be carried on a vehicle. This list includes some general exclusions, but the specific vehicle needs to be checked to confirm what can fit. Find that information here: Fit Lookup
Under 24" spacing: When the crossbar spread is under 24" this excludes the ability to carry boats, SUPS, surfboards, cargo boxes, tandem bike,
Under 30" spacing: 30" is needed to carry boats over 14'
32" Spacing: This is our sweet spot, where almost every product attaches
Over 42": When the crossbar spacing goes over 42" many of our products will no longer attach. All Cargo Boxes are excluded at this length
5) Do I need to secure my boat/surfboard/canoe at the front and rear with straps?
Yes, Please use bow and stern tie downs no matter what length the boat is. Wind from environmental conditions, driving, and passing Semi-Trucks can cause the boat to twist without these front and rear tie downs. When transporting a Boat, Surfboard or SUP always use bow and stern tie downs.