Pre war vs post war rake and trail

[Autocycleplane]

Until you have a fork alignment gauge like the Park tool it's hard to understand how bent most forks are on these classic bikes, not to mention any fore/aft alignment issues suffered over its life. I think the weight distribution of the handlebars has more to do with the OPs situation than geometry differences on those 2 bikes. I imagine the headtube angle and fork length to be very similar on both of those bikes and would have similar handling characteristics when riding.

As far as frame geometry goes, the prewar balloon bikes have a taller bottom bracket. Some of the prewar balloon models like the Model C, BA67, 1939 DX, etc. have headtube angles that are a couple of degrees more slack, which increases the front center measurement and obviously the wheelbase as well. These models do handle differently for sure, the wheel/bars do flop around more at slow speeds from the raked out head angle but they are great handling bikes at higher speeds. The chainstay lengths on the common prewar Schwinn balloon bikes are all the same - ladies/mens straight or curved - so the wheelbase differences all come from the the front center distance (BB to front axle). B10/B9 style bikes might be different, I've only had one long ago and don't know much about them.

 

[Tikibar]

I was working on my '36 Roadster today and had pulled off the handlebars and trust rods. The bike has a dropstand, so it's pretty stable in park. But when I went to move it, since the handlebars were off, I picked up the whole bike.

As soon as the tires left the ground, the fork spun round, so the front wheel faced backwards. Without the truss rods, there was nothing to stop the fork from going full reverse. I tried it several times and the natural balance is for the front wheel to spin a 180° and go backwards. Maybe that's what's effecting the balance on the prewars.

 

[scott1race]

When I was young, I had multiple ballooners, and rode no hands for long distances on anyone of them with no problems. I'm afraid to let go today. One thing I've noticed, when I've had bikes on the work-stand, is some of them, even with the fork correctly in the head tube, you don't dare leave them facing straight. They will suddenly turn and wham against the side of the tank. [I hope I phrased that right] It's not that the fork is loose in the head tube, it's just that it flops over easily, compared to others. Maybe this makes a difference when trying to steer no handed.

Yes, this is perfectly normal. Fork geometry works when on the road, not when the bike is in the stand. Most bike shop photos show bikes with the fork end lower than the seat end, simply to keep the front wheel from swinging around. Otherwise put a bungee cord around the frame and wheel like the others suggest.

 

[Autocycleplane]

Yes