Can my Surly Singulator be used minus the spring?

If you use it pushing up towards the chain stays and with a zip tie or two, it will work.

I'd second the zip tie idea. It works great, in facat better than under tension either up or down.
If I was running one Id still use it pulling up towards the chainstay.
Now, to answer your question, no it does not work w/o a spring. Well, not unless they have recently changed something.

The spring on my Surly tensioner broke many miles from home. I "zipped" it up (that's the way the tensioner was set) with a tie and it worked flawlessly. I replaced the spring at home, but don't see why the "zipped" system wouldn't work. Possible slight drawbacks with chain wrap and wear.

Thanks for the replies. I do have a fairly beefy zip tie now, as well as using the spring. Problem I am having with it zipped is that I keep popping the zip ties when climbing. Guess I need to go to home depot and get some really big and strong zip ties. The ones I keep using aren't lightweights btw, but there are larger ones. Guess I will try this route. Thanks.

oh yeah, I'm running it in the push up mode.

I used mine for a while w/those tough-ass rubber bands that come on hunks of broccoli .
Holds tight & gives a little, unlike a ziptie.