• 12-07-2019
    27.2mm to 30.9mm seat post adapter for heavy weights
    I have 3 bicycles that have a seat post diameter of 27.2mm that use a separate seat rail clamp.

    My fat bike is 30.9mm seatpost diameter with a newer style built in seat rail clamp.

    Where the 27.2's are strictly the post and no built in clamping mechanism. And require a saddle/seat clamp here is a link - http://i.ebayimg.com/images/i/260776426595-0-1/s-l1000.jpg

    I bought a decent seat with large springs for cushioning, it has the old style, but the rails are not rod like, more flat metal like 1/2" in height by 1/8-1/4" thickness, but clamped down the same way with SADDLE CLAMP SEAT CLAMP 7/8

    Do 27.2 to 30.9mm adapters work well for heavy folks, my riding is casual, but everyday of the year.

    Adapter - https://www.amazon.com/Gio-Seatpost-.../dp/B074NZPRPM

    30.90 seat post - https://www.amazon.com/corki-Bike-Se...dDbGljaz10cnVl
  • 12-08-2019
    The adapter isnt going to work too well. The extra diameter of the 30.9 will work better for you. More clamping area. Those posts and clamps youre posting are really kinda Wal Mart ish. Better quality MTBs have what your 30.9 bike has.
    If I were building myself a bike with a 27.2 post, Id use a Thomson post and a Salsa Lip Lock seatpost clamp.
  • 12-08-2019
    Get off the big ole sofa seats and start riding a 'proper' bike seat. You don't need the springs for cushioning, just a decent bike saddle. It's all about the size of your sit bones, not anything else. It is also way easier to pedal on a proper bike seat designed for pedaling.