I really don't have any idea how long it takes for the latex to degrade to a point it's no longer usable. So far I've only used them in one or two wars which is a pretty small sample size. If I were to totally guess I would say they probably need to be replaced within a year assuming you nerf a lot, but I could be totally wrong.
Without knowing how long it would take to need to replace the latex, I still prefer the extension springs. They're extremely easy to install and do not have variable tension which is a nice thing when testing similar blasters looking for consistent results. I still do like the latex since it's a lot cheaper and quieter when firing, especially dry-firing.
I'll have to look into those therabands. They're actually slightly cheaper than latex tubing, plus might be a little bit easier to tie since they're flat. The only real drawback I can see is this isn't available at one of the normal places I'd get blaster supplies.
I got to use the ESTL that I bought from Ryan last weekend. Over the course of the war there were several nerfers who noted that my range was decreasing. We did a quick chrony test to verify these observations and sure enough the initial velocity of my darts dropped from 230 fps to 190 fps. It should be noted that the way ryan sent me the blaster it was shooting 190 fps and I had re-tensioned the latex to get 230. (this was only a small amount of additional tension, i could get 260 with a lot of pre-tension.)
Currently I'm trying out using flat bungies. They are easier to use in pairs since they are flat as dEffeminateted below. I found that even with no pre-tensioning two bungies were a little much (260 fps) so I am currently only using one of them. With no pre-tensioning with 1 bungie the blaster shoots about 190 fps. With a small amount of pretension I'm getting ~225 fps. I'll make another post once i've used the bungies at the next war (2 weeks from now).
On a side note, the standard deviation of the initial velocities was under 10 fps, which is typical for a well built homemade.
I'm happy to report after a full day of nerfing today (0629) the bungie powered ESTL did not experience a loss of power.
Edited by koree, 29 June 2013 - 11:58 PM.