Variable fork geometry

mpie
mpie Posts: 81
edited June 2019 in Workshop
I have acquired a variable geometry fork (Columbus Futura Cross) with flipable dropouts which allow the wheel axle to be set in a more forward or rearward position (effective fork length does not change). I'm confused as to which is the 'stable' setting and which is the 'agile' setting'. Columbus data does not specify which is which. My understanding of bike steering geometry suggests that the rearward setting decreases rake hence increase trail and is therefore the 'stable' setting. However, the fork supplier states that the forward setting is the stable one. Having swapped between them, my riding experience suggests that the rearward one is more stable (easier to ride hands-free). So am I missing something or is the supplier wrong? If I am wrong can you point out where the 'rearward-->less rake-->more trail--> more stable' logic chain breaks down. The rearward position reduces the wheelbase of course, but I would expect that effect of that (~1%) to be small compared to a ~10% increase in trail.

Comments

  • sungod
    sungod Posts: 16,554
    i'd also expect rearward == less rake/more trail == more stable/slower steering

    might be an italian->english translation error in the documentation
    my bike - faster than god's and twice as shiny