Your line of thinking aligns perfectly with mine. Increasing the fork rake from 50 mm to 65 mm would drastically alter the bike's handling dynamics, completely deviating from the frame's intended design.
The reality is that toe overlap is mathematically inevitable for most size S road and gravel frames, especially when pushing into monster-gravel territory. To prove this, we have to analyze two distinct tire scenarios on a size S frame with a 600 mm front-center dimension (BB-to-axle, dimension "I") and a standard 170 mm crankset (like my Shimano GRX):
Case 1: NO-Clearance Setup (2.25" Tires)
Tire Diameter & Radius: A 2.25" tire has an approximate diameter of 740 mm, giving it a 370 mm radius.
Available Clearance: 600 mm (Front-Center) - 370 mm (Radius) - 170 mm (Crank) = 60 mm !
Result: This leaves exactly 60 mm of space from the pedal spindle (cleat center) to the tire.
Case 2: Full Monstrous Toe-overlap Setup (2.4" Tires)
Tire Diameter & Radius: A 2.4" tire bumps the diameter up to roughly 750 mm, or a 375 mm radius.
Available Clearance: 600 mm (Front-Center) - 375 mm (Radius) - 170 mm (Crank) = 55 mm
Result: This leaves only 55 mm of space from the pedal spindle to the tire.
Using my typical real-world setup: Shimano XC5 shoe (size EU42) paired with PD-M540 pedals—the distance from the cleat center to the tip of the shoe ranges between 88 mm and 108 mm, depending on cleat adjustment.Even in the most optimistic, hypothetical scenario—running the smaller 2.25" tire and slamming the cleat all the way forward (which is not recommended for proper bike fit)—we are still short by 28 mm (60 mm - 88 mm).To completely eliminate this 28 mm deficit by stretching the frame, you would have to increase the reach so much that the front-center (dimension "P") would enter L/XL sizing territory, rendering the frame entirely unrideable for a size S rider.
In my specific case, I run my cleats slammed all the way back, meaning I need 108 mm of clearance from the spindle to the shoe tip. The math leaves no room for compromise:
With 2.25" tires: I will experience a massive 48 mm toe overlap (60 mm - 108 mm).
With 2.4" tires: The overlap increases to 53 mm (55 mm - 108 mm).
There is simply no escaping the physics here. While eliminating toe overlap is a great goal on paper, forcing it onto a size S frame designed for high-volume tires is mathematically impossible without fundamentally ruining the bike's proportions and handling. In this size category, massive toe overlap is a reality we probably just have to accept.
EDIT to prevent double posting.
OK, I had a look at some gravels for that bb-to-axle distance.
Grizl CF XS (pre 2024) - 595 mm
Grizl CF XS - 625 mm
Grail CF XS - 604 mm
Topstone 47 - 601 mm
Topstone 51 - 605 mm
Checkpoint 54 - 606 mm
Diverge 54 - 615 mm
Revolut S - 607 mm
Addict s/52 - 608 mm
Locally popular gravel AL S - 609 mm
Grizl is well known to be designed long and to be used with short stem.
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This is a layout to accomodate "under-top-tube" bags, where you have just one bottle.
