If you make a track using a technique similar to mine with the hinges and boards, you know that keeping the transition from the downhill to the flats stable can be tough. You don't want your transition to have too much give because depending on a car's weight, it may have a disadvantage because of the track. The squishier the track is the more energy a car is losing and thus less speed. I've struggled with it using various things like sponges, cardboard and wood to keep things on the stiff and I never really liked any of them. However, thanks to a unique track piece I have found a way that I have confidence in.
Way back when I got started with this whole racing thing, I got the Hot Wheels V-Drop playset, which got me a good set of track and a good finish line. But the V-Drop track didn't come with your normal track connectors. Since the V-Drop was designed to hang from a door, the set came with connectors designed to keep the two lanes side-by-side.
This type of connector turned out to be a great thing because it kept the track side-by-side at the transition, but it didn't keep the transition from moving or giving as cars passed over it. With my track hinges recently moved, these connectors let me create a simple mechanism to keep track in place.
In short, I took a loop of rope through the connector, allowing me to pull the track down against the boards. To keep things in placed, I used a short bungie cord attached to the loop of rope and hooked it to the back of the downhill board. The rope kept things taught and the track secure against the boards. In my many tests so far this has kept the transition not only flat against the board but also prevents it from moving side to side, which then keeps all connecting track straight as well.
I drilled some holes in the V-Drop connector and thread some rope.
Then I put the rope through the space between the boards, created when hinged.
Pull the rope through so it brings the track down to the board, but make sure the V-Drop connectors are in position so they are where you want them, probably at the most bottom of the angle.
I used a picture hanging hook and nailed it to the back of the downhill board. Using a short bungie cord, I pulled the rope taught and hooked the bungie to the hook.
The final result being the rope being pulled through the board cracks, pulling the track tight thanks to the bungie. The bungie cord the makes it easy to unhook when you need to put the track away.
This adds a little hardware to your track but so far this have proven to be very effective at achieving its goal, that keeping things straight and solid. Now there is zero give in the transition which lets all the cars retain more energy when hitting the change.
However, now with a solid transition there is a new challenge...the angle. With a squishy transition, the car lost its energy and slowed it down a bit, now without that slow down, I'm finding the steepness of my hill angle might be too much because I'm finding more cars are flying off the track when they hit the curve. In theory, with a lesser angle on the drop the car will have an easier time turning downward force into forward force. This is still a work in progress to find a good balance but at least I don't have to worry about the transition getting wonky.
Of course, the key to this whole thing is the V-Drop playset track connectors. Without them this wouldn't have been as easy. I'm sure there is a way to fabricate some sort of similar connector using standard tongues but I'm not sure what that would be. But if you have a V-Drop set and don't mind your lanes being side-by-side, maybe explore this technique and post your results.