One of the potential problems of size for big people of the Helix is B) Effective top tube length: 590 mm Hopefully, this has changed since the Kickstarter campaign)


If you compare with the Brompton (M: 670, S: 700, P: 715), you see that it is much smaller and could be too short for big people, same problem than on the excellent Tyrell bikes that only fit for small people 9normal, it was made for the Japanese market).
The reason of this is a one piece frame made short to reduce the folded size, If you look how other folders (Birdy, Ori) solved this, they use a forward tilted stem.


For the Brompton tires, yes I know the Josef Kuosac Strozzapreti. , it is very fragile. But there will be Schwalbe One on the 2019 CHPT3 maybe Brompton will sell them as spare parts ?