Re: DW5000 Strap Drive
You can do one of two things: You can either replace the sprocket and chain on a DW5000 chain drive pedal with a cam and a strap (easy), or, get a DW6000 pedal that already has a model with a cam and a strap (easier). The 5000 is built a little more beefier, but not by much. I think the 6000 doesn't come with the bottom plate, however, but it's still a very smooth pedal.
My question is how fast do you need to go? In my experience this has more to do with technique than the actual pedal. I do prefer a strap sometimes though, as this is what I grew up on - there was a time when the idea of a sprocket and a chain was unheard of.