Metropolis looks to be the most practical and first to market with belt sprocket. But they have to change that clumsy gear shift cable for either a Duomatic ‘backshift’ or a Schlumpf ‘kickshift’.
With an MSRP of $300 is looks VERY attractive to me than 600-700 for the schlumpf one. They say all you need is a standard 68mm bottom bracket shell. would the strida 5 need some modifications for this? cause I never took apart my crank to my bottom bracket so i’m not sure if that’s what we have there. As for the gear changing, if they are going to sell that for $300 I’ll find a way to run the cable one way or another or position it just around the crank area so you can kick it to switch high and low.
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.