i was looking at the rather lovely Clockwork Orange bike and noticed the rite-hite (spelling?) thingy , I vaguely remember them when they came out so Googled about them and ended up on a museum piece about the first MTB the Breezer !
Still with me ?
Good !
In the days before MTB , we as nippers used to have trackers , usually a racer frame , with 26 x 1 3/8 (I think?) wheels , with cycle speedway tyres , motorcycle handlebars and brake lever , usually only a back brake , if you were really flash you had a Sturmey Archer 3 speed hub , but the hot-fix was a small childs bike front chainring welded to more normal "adult" cranks .
This was among a small group of friends in Bournemouth ( lots of heath and common land back in the 70s), but I wonder did they exist anywhere else ?
Thinking about it more , there was a cycle speedway track locally , and those bikes were similar , so maybe that's were they came from ?