I build model planes as a hobby, and to launch glider I use silicon tubing. The silicon tubing is cheap, stretches well, and has a high draw weight when pre-extended. This is in my opinion a superior alternative to bungees, and a cheap alternative to latex tubing. It comes in two sizes, 6mm and 8mm and cost either 4$ or 7$ for 10 METERS. Need I say more?
I have only tried the 6mm tubing, but next time I place a Hobbyking order I will definitely buy some 8mm tubing. I conducted a few tests to gauge the properties of the 6mm tubing.
I cut a 6 inch piece, and clamped an inch, leaving the stretchable length to 5 inches. I then stretched it to it's limit, which was as advertised, 30 inches. It stretches at a 6:1 ratio! The pre-extension capabilities because of this ratio are fantastic. See pictures below.
I was unable to stretch it to 30 and take a picture at the same time, but I do in the video.
This was a much less scientific test. I took the same 6 inch piece, clamped an inch, and put it through the center of a ten pound weight. It still had a little bit of stretch left in it. Super scientific. See photo.
Next I decided to overpower my beater Snapbow. It has performed very well with three lengths stretched to 4.5 times their original length. It had an easy, smooth prime, and was still penetrating cardboard with stock darts out of a four dart RSCB. I put on two more lengths, stretched to a full 5.5 times their original length. The prime was almost impossible, but as you will see in the video the power was insane. It shot invisibly fast out of an empty RSCB with stock darts. See video. After 5 shots however, I managed to break my catch. (EDIT: I managed to strip the plunger head wing nut) With pre-extension it is easy to get lots of power.
Watch the video to see for yourself, but in my opinion HKTS is a fantastic alternative to standard latex tubing, both in price and power, especially the former. I will order some 8mm tonight, I expect it to have about twice the power of the 6mm tubing.
Edited by Remzak, 22 January 2016 - 10:06 PM.