I am a average all-around travel photographer, but I will be getting some work focussing on Mountain biking. I am actually on the verge of buying a new camera set up entirely, so what would be a good set up; lighting needs to be portable and durable as does the camera. What are settings required for this kind of action photography? I would guess: high shutter speeds, ability to take fast bursts of images?
Well there are two ways you can go. On the cheaper, but (relatively speaking) lower (but still good) quality you can look at things like GoPro which is designed for being highly portable and durable. It has limited functionality, but can be easily mounted to a bike for example and shoot decent video or basic photography. You can also look at ruggadized point and shoots if you want to keep it light.
If you really want to maximize quality and don't mind some extra weight to carry (and a lot of cost, but with high value for that cost). Something like a Canon 1Dx or a 5D Mark iii is designed with professional durability in mind and has excellent (in the case of the 1Dx) and pretty good (in the case of the 5D mark iii) weather sealing to support use in hostile environments. You at that point would also want L series optics for the increased build quality which will help with dealing with the transportation and probably invest in a camera backpack for carrying it. It is looking at around 5 to 10 pounds of camera gear then though.
If you really want to get professional quality action shots, then the value of paying the extra for them and carrying the extra weight for the shots is definitely there. They are going to be much sharper and the AF will be much faster. If you ever end up doing anything in lower light they will also have a serious advantage. They also work with the full range of Speedlites and the 600EX-RT is a great high power flash for outdoor work, even in sunlight and supports built in radio sync so that it's reliable communication and can be used at a longer distance than the optical systems (particularly outside). The 600EX-RT units are also weatherproofed where as most of the third party flashes are not, so the 600EX-RT will hold up better in the wilderness.
You can go a little on the cheaper side if you want and use PocketWizards and third party flashes, but I personally like the level of control that you get in camera for the Canon RT system and think it is worth it if you are looking at the professional level.
Nikon also has a similar range of products available, but I shoot with Canon stuff, so I don't know the Nikon gear in as much detail.
Ultimately, the name of the game in photography generally seems to be that for the most part, value (per dollar) tends to increase as you spend more, even going up into at least the $3000+ range. For example, I had a 70-300 f/4-5.6 lens that was $600. I upgraded to the 70-200 f/2.8 IS II which is a $2200 or so lens, but the sharpness of the lens gives it about 4 times the quality without even taking in to consideration the richer color or the extra stops of aperture or better construction, so the value of the lens was much higher, but without a professional use for it (or being independently wealthy) I wouldn't really recommend buying it as a consumer unless you really REALLY love photography, even if it is a better value by far than the $600 lens I started with.
Oh, one other thought. I don't personally have experience with them, but Pentax is well known for the durability and weatherproofing of their lower end and mid-end DSLRs if you want an in-between option between rugadized point and shoot and high end professional DSLR, but I'd stay away from entry or mid level DSLRs from Nikon or Canon as they are not particularly ruggedized unless you want to take particular caution in their storage for transportation and use them only in fair weather conditions or with external weather protection (all of which adds weight).