Originally Posted by
KKBHH
Well, as long as the tire can increase slip-angle under increasing load then that is a gain in traction even though it is also increasing drift. See, if the tire takes a larger load without sliding then that is more traction demonstrated. This fundamental relates to either increasing speed and g-force in a curve or to a re-balancing of front-to-rear load transfer.
Now very stiff tires can take very large loads and that's how it's done. But a stiffer suspension is not an increase in load-transfer but just faster load-transfer. And that's why an increase in load-transfer is more traction on the turn-in. The balance of the front-to-rear load-transfer can be changed and the speed of the load-transfer can be changed but not the total load-transfer. Well, I mean that the total peak load-transfer is not changed with suspension stiffness. It can be changed with vehicle height or with vehicle track-width.
To relate all this back to bicycles, it could be said that many bicycles, like go-karts, just use tires and frame or fork deflection for a suspension.
All true in theory and good to see someone who at least understands the fundamental difference between dynamic load transfer and chassis roll. If track surfaces were all billiard smooth with no kerbs then you wouldn't need any suspension i.e. a go-kart sat a few mm off the ground would be the best solution. But unfortunately there are kerbs and many lumps and bumps on all race circuits I've ever been to. Some are much more bumpy than others obviously. So you have to compromise between the speed of response to a steering input and the tyre load variation when running over all the bumps and kerbs. A softer suspension reduces tyre load variation, which nearly always results in faster lap times and less tyre wear (providing it is very well damped). So why not go really soft then you ask? Well that causes potential issues with geometry (camber, toe etc) and then there's ride heights and of course aero performance to consider.
But to be honest this is all pretty irrelevant to bicycle frame flex. I only mentioned this to highlight the potential difference between someone's subjective perception of stiffness and objective performance. They don't always match up. Like in this race car example, a stiffer suspension might well feel like it has a sharper turn-in response, but you might not notice a loss of grip mid-corner or loss of traction on a bumpy exit (especially with TC). That's why we have data and engineers to analyse it to death!