Dozer Question ?

[Rvjimd]

I'm sure some of you can answer this quick!

What is the advantage or reason for some track systems having the drive sprocket mounted above the front and rear sprockets?

I'm guessing it made it easier to mount the tranny in the frame up a bit higher? Or, is that top sprocket NOT the driver and just an idler?

Are there other pros and cons?

I'm thinking on a 1:50 conversion it may give me more room or better access in the triangle version?

Jim