Ah, clay renders! I would recommend that u download Eki's PlugPak here:
http://www.kolumbus.fi/erkki.halkka/plugpak/
and then create a scene using the Overcaster plugin picking whichever lighting setup that u want(there is a tutorial on how to use overcaster on the site).
then
add your bike model and assign all of it's surfaces the same texture. I just use the default texture with a little bit of specularity added to it. Or if you're bike has way to many surfaces to copy and paste the new surface into each one then Open up you're bike in modeler and select all polygons and give them a surface named "clay" or sumthing 2 that effect. Then save youre bike as clayharley or sumthing like that. Then just add clayharley to you're overcaster scene instead of the original one, edit the clay texture as u wish and render. If you have any questions feelm free to ask! Hope this helps!