I think I found my answer on a post several pages back. They recommended 10" clearance from top of rail to lowest overhead. Sounds ok to me.

I'm just getting into G using Bachmann metal track. I come up with a layout that will have 2 or 3 track levels, running at least 2 trains. What is the proper distance between levels? I will be running Big Hauler type of equipment to start. Also, what is the max rise percentage and gradient degree? ie: 4" rise in 72" of track. My calc indicates 5.66% rise which equates to a little over 3 degrees gradient. Am I even close??   

Everyone, thanks for the suggestions. There are several Garden Railway clubs around. I'm in Hamilton, OH, just a few miles from one of the largest indoor G-Scale layouts, EnterTRAINment Junction (I have annual pass for me and ny 4 yr old grandson). I purchased AnyRail about a year ago and have designed several HO and N layouts but then sold all my stuff when I got the bug for G. The main reason for looking at G-Scale was for grandson. He is able to handle it easier and I can get 'cheaper' items for him to play with (battery operated). My area is limited to a max of 30 x 40 but I will start out with about 12-14 x 20-24. Future expansions will be with brass. I can cut an opening in the foundation and head outside. Again, thanks for your help.

This would be for indoor.

Where can I find tracks plans (if available) that uses Bachmann G Scale steel track???

That explains it. Thanks.

For $15, each engine, plus shipping to them, Bachmann will repair or replace. I've sent in several older engines (two 4-8-4 and one 0-6-0) and they sent replacements.

I haven't looked at the engines yet so I thought I'd ask while on the board. The DCC Spectrum 2-8-0 has a fake knuckle coupler on the front. Can this be easily replaced with a working coupler?

I am converting to DCC from DC. I recently purchased 4 DCC Equipped Spectrum
2-8-0. I also have 1 remaining DC engine. I test ran the new Spectrums and they seemed to run sluggish compared to the DC. They were running on a regular DC (not DCC) test track oval 150" in length for 5 laps. The DCC engines averaged 17.46 secs to 18.89 secs per lap. The DC engine did the same oval in 8.84 secs average per lap. All engines are brand new and were 'broken in' as advised by Bachmann. Is this normal under these conditions?