Okay, I'm triggered!
I've a question for you; What exactly is a 'heavy bike'?
A bike with a LOT of weight?
I'm posting a few links to my previous posts here; which will help you distinguish between 'sport' and 'heavy' bike 
Enjoy!
[Click the expand button at the right to view the whole post with snapshots]
I hope it clears any confusion! Without the help of my friend @ryu.iori; that wouldn't have been possible! So all credit goes to him!
If you're grateful for the enlightenment; thank him; not me.
Good Day!