I think Strida 5’s BB shell is shorter than 68mm. That’s why on Strida there’s a sizable gap (compared to normal bikes) between the BB shell and the left crank arm. However, the real question here is whether these products can be coupled with Strida’s eccentric BB piece. If they do, the length of the BB shell is probably irrelevant because you can lock the EBB piece onto your Strida’s BB shell.
Take a look at Schlumpf’s Strida kit below; the Speed Drive is mated with an EBB piece that Ming developed for two-speed Strida. This does raise the question whether the regular EBB piece on Strida 5/LT/SX can be used without modification on a Metropolis or Trident Drive.
