Ciao.
Sono anche io interessato a questa questione però tu e warrell79 state dicendo due cose divergenti mi pare.
A leggere il link indicato sopra mi pare che warrell abbia ragione
No, non sono divergenti, i telaisti utilizzano forcelle con offset ridotto per evitare di avere la ruota anteriore troppo avanti con geometrie moderne, cosidetta "longer & slacker".
Se invece hai una geometria più tradizionale, con bici più corta di reach e angolo sterzo più chiuso avere la ruota anteriore più arretrata è controproducente, la mia considerazione era riferita all'opportunità di utilizzare un offset ridotto su geometria non dedicata ( reach minore e angolo sterzo meno aperto).
Ti allego un link molto interessante con le considerazioni di telaisti di vari marchi
nsmb.com
What Does a Shorter Offset Accomplish?
Bikes with a longer front-center and a slacker head angle push the front wheel further away from the mass of the rider. Shorter offset helps balance handling characteristics to enable the bike to be ridden comfortably and quiets steering, helping stabilize the front wheel. When the head angle gets slacker, the trail is lengthened and wheel flop can make handling feel unstable, requiring more input from the rider. The shorter offset also brings the hub toward the rider’s mass making it easier to weight the wheel and provide steering stability.
Shortening the offset increases the trail measurement, which is also what a slacker head angle does. As you're about to read, some manufacturers are looking for that increased stability associated with a longer trail measurement, but without making their bikes much slacker. To do this they're shortening the offset and making less drastic changes to other geometry elements.
Cesar Rojo (Unno Bikes + Cero Design)
Why do you think there's been a sudden increase in interest for shorter offset forks?
Well, it's easy… With people realizing we need slacker geometries, making the bike too slack has downsides. The most important one is having the front wheel too far from your handlebars and not putting enough weight up front to turn, so reducing offset generates a similar effect without having to slacken the head angle.
Colin Hughes (Ibis Cycles)
Why do you think there's been a sudden increase in interest for shorter offset forks?
As suspension has improved we've started going faster and that means we need more steering force to initiate turns and hold a line. The way to do that is to increase trail, the offset of the tire contact patch from the steering axis. The two ways to increase trail for a given wheel size are making the head angle slacker or reducing offset. By reducing offset instead of making the head angle slacker you keep the wheelbase shorter. Without the short offset, the Ripmo's head angle would have needed to be 64.5 to get the same trail. The downhillers would have been fine with that but it would have reduced the bike's versatility.
How would you determine the best use of a shorter offset fork? What parameters are involved when you consider making a shorter offset benefit the handling of a bike?
A shorter fork (offset) could be used anytime you want to make a bike feel more stable but it is going to add weight to the steering. The way to counteract the handling feeling too heavy is to make the seat angle steeper. That puts more weight on the bars, making them easier to turn.
Have you found there to be any limitations with geometry and the use of shorter offset forks?
You would not want to put a short offset fork on an XC bike where the wheelbase is already short because it's just going to pull the wheel back further. It's a trick for bikes that already have long wheelbases where you don't want make the head angle any slacker.