Gravel Wheels/Tyres on a Specialized Roubaix SL4 Sport

[aquaratza]

I bought a Specialized Roubaix SL4 Sport through the classifieds (not disk brakes). I want to give road cycling a go. The bike is very cool. It's pretty, unbelievably light (especially compared to my Camber). I'm investigating putting gravel wheels/tyres onto it. There are a few fun back roads near Durbanville including lots of gravel to explore. It's probably not possible to install gravel tyres/wheels, there's very little clearance between the front fork and the current tyre (enough for a finger).

 

Does anyone have any experience or advice for putting gravel wheels onto a Roubaix SL4 ? Unreasonable ? Buy a Diverge ? Stick to your MTB ? 

 

Thanks