.. How to get the mine bike to Goal?

If you look closely the rails go so that you should get the mine bike to the tracks in the back.

The Shunting Lever Box will move the Mine Bike to the other track.

Yes, it is missing the lever.

I think there was a lever in the Outer Turn (when you drive with the Mine Bike).

I think you have to walk there...

Oh yeah, your bat signals don't work. Shed some light into the tunnel?

Go and grab the lever from the Outer Turn.

Attach the Lever to the Shunting Lever Box. Turn the Mine Bike to point to left (by driving it) and use the Lever. Drive the Mine Bike under the Funnel.