Hi-Rail vs Scale...help me understand

Scale wheel sets have small (prototypical) flanges.  Hi Rail wheels have much deeper flanges to accommodate the track typically found on a three rail layout.  Scale wheels require more consistant track work in terms of evenness and true/accurate gauge.  They also don't handle tight turns the way hi rail flanges can.

Thanks a lot Chuck...that is a big help

The "scale wheel" versions are generally for 2-Rail O Scale modelers, who have DC power in their 2-Rail track. The scale wheel profile is more prototypical than the Hi-Rail oversize (or pizza cutter) flanges. The "scale wheel" models also come with fixed pilots and mounting pads for Kadee "scale" couplers, i.e. no big lobster claw electro couplers.

Many 3RS (3-Rail Scale) modelers have been purchasing MTH's "scale wheel" diesel models and then changing out the scale wheels, replacing them with MTH Hi-Rail wheels, and then operating the more "scale like" diesel models on their 3-Rail track.

Scale wheels are wheelsets with the smaller flanges, like those used on 2-rail locomotives and rolling stock. Hi- rail wheetsets are the larger oversized wheels that come on most 3-rail engines and rolling stock.

Geno

Thanks everyone...very helpful

bill

scale wheels equate to 2 rail scale modeling

Hi-rail equates to O gauge three rail track and three rail switches  which require the oversized wheels for the higher track profile and sharper curves.