Sunday introduced the Wave downtube at Interbike in 2007. This unique feature quickly became a centerpiece in our goal of bringing riders a frame that’s both strong and light. Surprisingly, a lot of people didn’t notice the Wave when we initially showed it at Interbike, and to this day some riders STILL haven’t noticed it. There are also riders out there that are unaware of how well the tube design really works. However, with that said, I have heard countless stories from Sunday frame owners about what their Wave downtubes have been through. It’s understood that the tube won’t take “everything” thrown at it (after all, it’s still just made of 4130 chromoly), but it will take a lot of the abuse that ordinary round tubes won’t, and once the downtube of a frame has been damaged, it’s only a matter of time before a new frame will be needed. At this point it’s been over two years since we began testing the original prototypes, so I figured that it was time to show some photos of what a Wave downtube looks like on the inside.