We have been in this hobby for many years, racing, riding, promoting and wrenching. Here is a list of shops we have had good experiences with.
The owner Kelly is a genuine great guy and he has been supporting the sport for 10 years. This is a great place to have an engine built, dyno tune and more. They also work with manufacturers to make their own unique parts to solve problems like Raptor head studs, LTR shift mods etc.
Co owned by an ex Pro ATV racer and a graphic designer this place can set you up with the best graphics kits around and great engine builds, suspension setup, dyno tunes and general advice. Full service shop.
WARP Off Road
I am biased since I am co owner of WARP off road. We are a new business dedicated to selling and building top quality ATV products. We have a store in Phoenix but most business is done online. We are currently focused on Earth X Lithium Ion batteries, Motowoz Shocks and our Wraith 1000 desert beast.
Manufacturers of top quality suspension components. Several of the people on the message forums work here. They are well known in the industry. I have been using their suspensions and axles for many years without any issues.
Other companies I have dealt with and recommend. Some of these are current sponsors of mine.
Fasstco Flexx Handlebars
American made, top quality handlebars that truly reduce vibration and make riding more enjoyable.
The only grips I run on my quad. I have found thinner grips help reduce arm pump for me. The bug cushy grips might feel nice but they seem to increase arm pump in my case.
These guys make great riding gear and also sell many hard parts like pistons, ball joints, bumpers and more. Anytime I place an order it arrives within 48 hours.
These tires perform as good as Maxxis tires for 1/3 of the cost.