The motorized bicycle in my avatar goes about 20 mph.
Looks to me like you're breaking the sound barrier!
When you passed by, I spilled coffee all over myself and cursed like a sailor!
(he-he!)
Uh, yeah, about that...I deleted my post about the avatar bike since I sold that one a couple whiles ago. The NEW AVATAR bike, is a regular old frame mount engine.
I photoshopped in the smoke since none of the two stroke bicycle motors that I have run smoke. If you look closely at the photo (don't know it it's visible) the smoke also has stars in it....I was just palying around with photo shop, which I am not-so-good at.
....and maybe your chain too. I did that once and the tire started hopping and I thought I was gonna break everything. Just be carefull and have the camera person ready!