My mate needs a new 30.9mm seatpost for a recent purchase. Which would you recommend, ideally 410mm or longer….?

thomson

What size frame is he on? I use that size on a 20inch frame but have very long legs

Thomson is your best bet

Roox

Titec do a couple of 450mm ones, but they look like this:

lighter/more expensive one
heavier/cheaper one

Surely if you need a post that long the frame is too small 😕

or companies don't make frames big enough .All my 20 inch frames have 400 mm pins just over the limit line.Why don't many cater for big people who ride with their seat at the right height .They all seem to cater for those who ride with a really bent leg no matter what discipline they do

Looks like a robot monkey fist

LBS let him walk away with a small frame? He's about my height 5'10" ish

or companies don't make frames big enough ………Why don't many cater for big people who ride with their seat at the right height

Because there is no profit in us. Most things in life are made for something like the 80th percentile – 10th to 90th – simple economics. Few people are above or below those limits. You just have to look harder for bikes to fit.