very important question ref carbon forks

can i get away with using 425mm crown to drop out forks on my 16″ 100mm corrected giant xtc alliance or will i have to use 445mm crown to drop out will the handling be that much too whippy with 425mm ❓

If you measure the axle to crown length of your 100mm forks and then deduct maybe 25 – 30mm sag, perhaps a touch more and you get to somewhere the acceptable length of a rigid fork length that would give a similar ride.

For every 20mm or so each way the head angle will slacken or steepen, around this ‘sagged as riding’ setting.

My cheapo XCM 100mm fork seemed to have quite a long axle to crown of 490mm ish.