Originally Posted by
vane171
That is interesting stuff about the fork geometries, I believe what you guys say up there but as I said, on my vintage bike, I am sure I don't have toe overlap
I don't doubt it. I'm actually in a similar boat: I don't get toe overlap on either of my vintage steel road bikes, but there's a bit of it on my modern road bike. My point was simply that this doesn't have anything inherent to do with how bikes are and were made. There are old steel road bikes with short front-centers, and there are modern road bikes with long front-centers.
Actually, I'd disagree with the folks in here suggesting that your modern bike has a short front-center
because it's a TT bike. A properly-fit aerobar posture generally puts the rider quite far forward over the bike, so to avoid being squirrely and having the rider feel like they're constantly "going over the front wheel", modern frame designers usually built slightly longer front-centers into their TT bikes than their road bikes.
I think one factor might be the bike being on the bigger end frame size for me, while this TT bike is on the smaller end of the range for my body size.
That could absolutely play a role. Bigger frames usually have a longer distance from the bottom bracket to the front wheel axle.
Still, don't touring bikes have the front wheel axle placed more forward relative to the fork stering axis to achieve stability at the expense of easier steering?
Hey, road touring bikes still exist, slightly. They do usually have longer front-center than performance-oriented road bikes, although I suspect the largest reason is simply extra clearance for wider tires and/or fenders.
the modern racing bike frame geometry has this angle quite steep for quick steering response, agility, likely steeper angle than vintage bikes have
Depends on how vintage is vintage. Things slacken off if you go
really far back, but typical racing bikes circa 1980 have very similar steering geometries to racing bikes today.
Don't make the mistake of thinking that the long slack front-end necessarily gave the really old stuff a heavy steering response, though. Slackening the head angle increases steering trail
if you don't also increase the fork offset, but they usually did, to the effect of creating a fairly low-trail steering geometry.
while the curved fork geometry was done to achieve softer ride
The curved fork was primarily done because it's what was viewed as convenient for manufacturers. Fork blades were manufactured straight, and bent to the required offset by the framebuilder. This meant that builders could build bikes with a variety of fork offsets without having to inventory lots of permutations of fork crowns or fork blades.