Yes the idea behind the Portacatena was to allow a ridr/racer to actually shift the chain onto the holder get a quick wheel change from the team or Neutral support guy and after a little push shift back on to a gear and ride away. It is suposed to speed up and make race wheel changes easier.
If you look close at the right shifter, you'll see an extra lever on the bottom. The backing plate has a little notch in it. When you get to the small cog, you pull/flip the littlelever and push the shifter past the notch and the chain should shift onto the holder.
I actually have a 5spd FW enroute. I figured the Velveeta went well with the Bourbon which went well with the DUI bars!
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk