I have a number of Athearn Hi-F F7's and I'm a fan of them. I use an A-B consist of them to pull a very loosely interpreted version of the Santa Fe Super Chief. Yes, they do require a lot of voltage to start, and don't do slow speed well. But, for pulling a reasonable length passenger train at a good clip they do it smoothly, quietly, and effortlessly. I like to run passenger trains at an exciting speed. The Hi-F drive is capable of slinging the cars off the track in corners.
The maintenance on them is not too bad. I disassemble the motors and clean/polish the armatures and properly set armature end play with shim washers. I have experimented with good success the addition of small neodymium magnets on either side of the open frame motors to boost their efficiency and power by quite a bit. This also improves their low speed operation. If you are on DC and use a pulse type power supply then acceptable, but not prototypical slow speed can be had.
I use small silicone tubing for the shaft connections, and polish the friction areas where the driveshafts go thru the stanchions. I lube the motor bushings, stanchions, wheel bearing bushings, and clean up the screw-connection electrical contacts. These are 'all wheel pickup', and 'all wheel drive' locos. Not bad, for fifties technology. As mentioned, the 'rubber bands' can be as simple as a certain size Goodys 'hair band' from Walmart. You have to disassemble the trucks to change bands, but its not a bad job. They last a reasonable amount of time before needing changed.
Even though these were designed by Athearn to bring costs down to affordable levels back in the 50's, I find they are built well. Dead simple, and everything (motors, frame, trucks) are nicely cast metal and good materials that stand up to time. I've rehabbed 5-6 of them and they all run well after a good going-over. Parts units are cheap to come by as many folks hate them. I rather enjoy rehabbing them and running them!
