Athearn Hi-F drive

Empire Builder

Great Northern fanatic
I recently got ahold of a 1998 guide to Athearn HO model trains, & looking at the F7's in there, I noticed that sme had a "HiF" rubberband drive. How does this work? I've never knew about model trains having a rubberband drive before. Also, in the same list, I noticed that some were maked "Grd" for geared & some were marked "Pwd" for powered. Is there a difference between those 2? I thought they were the same. Also, what's the difference between a geared F7A & a "super geared" F7A? I know that the F7 I have is marked as a "super", but what makes it different than a normal geared F7A? I noticed that the "HiF" & the "geared" ones were older, like from the '50's & '60's, & the "super geared" ones were made in the '90's.
Hi F drives were just as you said, the motor shaft extended over the trucks and was connected to the thick axles with rubber bands. The Athearn RDCs used this system until they were discontinued some years ago.

Geared meant like other diesel models, with drive shafts to the gear towers in the trucks. Super Geared was just a marketing ploy to indicate the F-7's had huge weights inside, which gave them more pulling power - traction.
Ditto to all of the above. The Hi-F drive was also impractical and gave the loco a very high top speed, something like mach 2. They are also terrible pullers. I like the geared models much better and I have several super geared locos. These days they're called 'Super Power locos' and can pull big loads.
Hi Eric just to give you an idea. The rubber bands were long gone before I ever got this one. There used to be an Ernst gear kit for converting them to almost normal. A real telltale feature of these models with the shell still on them is to look at the wheels. The axles are almost the same diameter of the wheels (thats how the motor speed to the wheels is reduced).

Those HI FI drives had a jerky start due to the bands but,would run fairly smooth at speed considering and the bands would last awhile before they broke.Advanced modelers would repower the Athearn GP7/F7 with Hobbytown of Boston drives with flywheels*.Some would replace the motor and bands with a Pittman double shaft motor and thick rubber bands that was black in color and look like round rubber "O" seals..This rubber band drive was superior to the Athearn rubber band drive and did improve the operation.
Of course the Hobbytown drive was the better choice.

* These flywheels was large and thick and would fill the cab of the GP7 just like they did in the Hobbytown RS3..These drives was very smooth when properly built and was considered top of the line drives.