• The Aprilia RS 660 middleweight sportbike was spotted testing.

• Sources report seeing one in street trim and another in race trim.

• We are still awaiting news on its launch date and pricing.

Remember the sexy-looking Aprilia RS 660 Concept at EICMA 2018? Spy pictures of it testing have started to make to make rounds in Facebook.

There were two bikes spotted: One in street trim and another in race trim.

This is what we know so far. It is a parallel-Twin engine based on the RSV4 but with the rear cylinder bank removed. We are curious to see how Aprilia arrived at 660cc since half of 1078cc is over 500cc…

Aprilia claims the bike may do more than 100 bhp, making the RS 660 a supertwin. The Noale-based manufacturer is aiming for a lightweight and high-performance bike. It would be eligible for the Isle of Man TT’s Lightweight TT class if the engine is below 650cc.

We also hope that Aprilia will include their APRC electronic rider aids package on the bike.

The question on everyone’s mind is the price, of course. Will it be priced to compete toe-to-toe with the current crop of 600s and 650s? Needless to say, there’s no point if the RS 660 costs in the regions of RM 70,000 to 80,000. However, Piaggo has shown their aggressive pricing strategy with the Moto Guzzi V85 TT recently. The price has totally undercut bikes of the same category from all other manufacturers.

Another question is when will the RS 660 be launched? 2020 is when Euro5 regulations are implemented, so it could be so. Lastly, will Aprilia use the engine platform to build other type of bikes?

We shall see.