From La Parada your best bet will be Tokai mtb trails - Day permit is R97 CASH at the gate.
You can easily cycle from the Restaurant to the start (maybe 6-7km).
If you want a nice challenge go straight up to the top of the mast, as you come down again where you will pass a little picnic table bench, you go straight up there which will take you into Silvermine reserve.
Cycle up the tar road to the first car park on your right and head back onto jeep track. Keep following the road and just about 100m before you reach the top of the climb, there is a path that veers off to the right known as the DONKEY trail.
This takes you right back down and back into Tokai trails.
Here you can head back up the same path you did heading towards silvermine reserve and go up to the right where the road splits again and ride down the COBRA (black trail) and continue all the way down the rest of the snake trails towards the exit gate.
This should give you LOADS of elevation and a good 70 odd km and some really cool trails.
Disclaimer - access points to Cobra and Donkey trails are not very well marked.
The bike shop down the road from the start of the trails (at the roundabout) has a really cool picture of all the trails on their wall that you can take a picture of to help you with a bit of guidance.
First time on Tokai trails, it's quite easy to get a bit lost.