Hello everyone, I am in the midst of confusion over the use of upgrade material for my Brompton bike. I am confused about the use of titanium seatpost which also results in bobbing when pedaling. and on the other hand the use of aluminium is also very rarely used by Brompton bicycle users. Bobbing is commonly known amongst cyclist to be a very ineffective because energy is wasted due to titanium flexibility that cause bobbing (movement to left-right shake). Perhaps anyone can help by giving input or experience on this matter ? Thanks in advanced.