TREE BICYCLE CO
 
We introduced using 7075 T6 aluminum for sprockets to BMX in 2002 with the Tree Original sprocket, well back then it was just called the Tree sprocket. At the time people had to change their 6061 sprockets every few months. I now see photos quite often from people that have been running the same sprocket for 6+ years. It is currently the strongest sprocket available.
 
It has 5 different crank arm bolt positions to help extent the life of the sprocket.
 
The sprocket is machined in a way that removes material from the triangle shaped holes that is not needed and leaves the material necessary to form a structure of high strength to weight. With a classic looking design that has a timeless appeal. The teeth have been modeled after the tooth shape used for industrial machinery. In industrial situations this engineered tooth shape keeps machinery running quietly and smoothly at very high RPM's. For BMX it makes it the smoothest running sprocket. Also the teeth are made tall to prevent the chain from derailing. 
Anti-loosen bolt drive slot. The crank arm bolt hole is intentionally undersized where it is necessary to almost thread the bolt through the sprocket. As opposed to normal sprockets ours cannot rock back and forth and loosen over time. This prevents the bolt from loosening and falling out during riding.