Originally Posted by
Jipe
Titanium alloy is another material than steel alloy with different mechanical properties.
Normally, when changing the material (even changing the type of alloy), the frame must be redimensioned to take this difference of mechanical properties into account.
Which I am afraid wasn't done for those Chinese Ti Brompton frame clones.
But you can't tell that. First they are roughly the same strength steel and titanium. Second, they may use the same outer dimension and not the same inner dimension. Buying Chinese Ti is though a pig in a poke. I guess on eBay you could go by Sellers feedback buy that is not that reliable.