Well, I hate to be the barer of bad news but the whole tie squeezing thing doesn't work. It was a good idea but I've tried it when a couple guy's and I got together and all built our own retarder using that rail squeezing idea and all we got were the same results. Derail. What happens with that is that in such a small scale you have to have really good wheels and trucks. The design I made was meant for Kato trucks as they make the bets rolling trucks on the market and that's all I have on my cars. The wheels have a taper to them and the rail has a bit of a crown to it (depending on what track you use) And what happens when you squeeze the track is that the taper on the wheels run out, then it's the flanges. The flanges will get tight but only to a certain point and they have very little tolerance which will slow the car a little but won't do any justice so then the flanges will climb up on top the rail head and over on the ground she goes. You'll even get the same thing from hand laying track if it's not gauged right. I'm not sure how a retarder works but I do know that they use a very high pressure rubber pad that is pushed against the inside of the rails against the inside of the car wheels to slow it. The design I drew up has the paddles high enough above the rail head to prevent derailment yet won't interfere with anything hanging from he car. Ahhhhh. I'll come back and explain it and read over this to make sure I got it right. I am extremely sleep deprived as it be 3 days I've been up working on day 4 at 5:30am