Originally Posted by
CEBEP
As I’m reading the thread backwards came across this message. If you happen to carry heavy loads on the carrier block bolted directly to the frame, I’d strongly recommend to use Brompton original plastic carrier block. Unlike OEM aluminum carrier blocks which have very narrow contact surface to the frame, Brompton original carriers block wraps the frame around which adds to the sideways rigidity to the assembly and protects against lateral forces.
Carrying heavy loads on OEM aluminum carrier block with heavy side movements can rip the bolts from the frame, which is the last thing anyone would want, specially on a titanium frame.
I don't think this is an issue or if it is, it is not major. On most of the commercial mounts you the blocks mounting to alloy, They may not hold the screws as the Brompton which is steel. If you look at the actual mounting "blocks" themselves, the alloy ones have sides that fit over and around the alloy block they mount on. The Brompton OEM ones do have a larger area and that will factor in for vertical loading, but may tend to rotate for side loading. Also, loads on the sides are small unless you crash. I have not heard of problems with the alloy blocks, though looking Aceofix they seem real cheap looking. Most of the mounts used to add a block, resist side rotation by friction since they are not brazed on. Under heavy side loads, they will more likely rotate.