This might come under the heading of "nit-picking", but consider the following for what it's worth (maybe nothing) but this is a little something that has sort of bothered me for a long time:
Many times on this forum, an expression comes up that really isn't quite correct, and might be worth discussing. Quite often, someone will advise, and certainly with good and proper intentions, to avoid "slipping" low band. Again, maybe nit-picking, but to avoid confusion, especially for the fellow that is new to Model T's and trying to learn, technically, you absolutely must "slip" low band when starting out from a dead stop. The point that is usually being stressed is that slipping low band is what wears the band lining out, we understand that. The only way to begin applying power to the rear wheels is to slowly depress the low pedal until the car begins to move, and the proper way to do this is to apply slowly increasing pressure to the low pedal gradually until the car has gained enough momentum to allow the low pedal to be pressed down hard enough to stop the low speed drum from turning and to LOCK UP the drum from any more rotation.
So, I believe the proper expression should be to keep slipping low band to an absolute minimum. Again, it HAS to slip a bit initially until you can completely lock up that planetary. The only way to completely avoid slipping low band at all would be to be parked on some degree of downgrade, and let the car begin to roll downhill until it picks up enough speed to allow the low pedal to be immediately and quickly pressed down hard hard enough to immediately lock up that planetary (lock up low speed drum). This would of course require perfect timing to effect "lock-up" at the absolutely perfect speed.
So, all of that to say that a good habit to develop is to always keep slipping low band to minimum. To do this, and I would try to teach a new Model T driver to practice this (or anybody for that matter) and to make every start-out from a dead stop an exercise in practicing how to keep slipping low band to a minimum. The focus should be to keep engine rpm's to a minimum (idle speed whenever possible) and pressing low pedal hard enough to effect total "lock-up" as quickly possible. As an aside, it is interesting that an engaged Ruckstell, with car on smooth and level pavement allows total lock-up after a minumum of the first two feet of the cars forward movement! But even in direct Ruckstell, or with a "T" with conventional rear end, total lock-up can be effected in as little as just a few feet of forward motion of the car. Again, this takes practice, but that is what you should be doing every time you start out from a dead stop,....practicing getting that low speed "LOCKED UP" with as few revolutions of the low speed drum as possible. It's a good habit and well worth the effort to develop this skill.
However,....bottom line,....to say, "avoid slipping low band" (or some such phrase) is nearly impossible,....it has to slip a bit. This will probably be considered "nit-picking" by a few very experienced Model T drivers, but that's okay, I don't care. I once rode with a guy who'd been driving Model T's for many, many years who had a habit that I just couldn't believe! While stopped at a stop sign on a slight upgrade, waiting for a break in traffic, he would actually hold the car from rolling backwards (downhill) by keeping pressure on the low pedal and slipping low until we could finally pull out into traffic! Kept my mouth shut, but frankly, I wanted to scream! As in,....what the heck are you think'n man,....? Don't you realized what you're doing to that low band and drum? Unbelievable! O.K,....enough,....again FWIW,......harold
What's more to the point, is that there is very little need to rev the engine appreciably before engaging the low band. It's the combination of revving the engine before ever pushing on the clutch pedal, then feathering in the clutch, that causes excessive band slippage and wear. It's not like a "modern" manual transmission, where you need to rev the motor before letting out the clutch. You can get a T to move at, or near, an idle speed using only minimal low band slippage. At once moving, you basically apply the clutch firmly, then pull down on the throttle. With practice, this can be done smoothly.
ugh.. "At once moving" should read "Once moving".
Good point Harold.
I'd equate the starting 'slip' to be much like (for those that remember) learning a tight 3 speed clutch plate machine and not to do a 'dump' but then act like you don't wish to smell clutch plate either. Like Jerry points out, the difference being that you need almost no pre-idle RPM in a T
The other side of 'slipping low' is on an up-shift and that is where I believe a lot of the concern and real problems come from. Simply put...you can't feather for long or you pay for it at some point! IMHO Proper T driving is to almost dump it into high from low with the torque all but removed at the same instant, and learn to use the sticks to harness your torque surge.
With a little bit of practice you CAN go from low to high with almost no slippage, and no 'chatter/skip' and be as smooth if not smoother than an automatic transmission.