Hi, I am the person who posted the videos at the beginning of this thread on YouTube. The secret of these bikes is their low-pressure tyres and when ridden out of the saddle the bicycle rotates over obstacles whilst the riders body does not. This is the same technique that BMX rider's use, so these bikes are basically large wheeled BMX bikes. However, ridding out of the saddle for long periods can be tiring and so nowadays long-travel sprung seat-posts like the Thudbuster, provide better shock absorption whilst seated. I personally like to attach these suspension mechanisms to dropper posts.
To achieve the upright riding position you need a frame with a shorter distance between the saddle and the handlebars than a standard mountain-bike. An easy way to to do this is to choose a small frame size and then use a longer seat-post, longer upright stem or a BMX stem and riser bars.
There are full suspension 26" wheeled versions of Apps' bikes that use old Giant NRS frames. I also like the idea of building a 27.5" 0r 29er version using an old KHS Prescot, Flagstaff or similar Horst-link XC frame as the smaller versions have frame geometry that are similar to Apps' own frames.
Geoff Apps is alive and well and his "Cleland Cycles" site can be found online.
His 'site' includes a page on spinal health.
Last edited by Graham Wallace; 08-22-22 at 06:04 AM.