Re:
Here is an interesting letter published on the CTC letters page in 2011:
MTB ANTECEDENTS
"Like many pre-MTB or ATB cyclists of
my generation, I remember making my
own ‘tracker’ type bike for riding in the
local forestry and off-road tracks in the
area. It consisted of an old ’70s racer
from the tip fitted with cow-horn type
handlebars and ‘knobblies’ from the
local bike shop.
Around 1980, however, I remember
being given a new Vindec Trekker bicycle
by my parents, which was an excellent
bike. It had a three-speed hub, fork
strengtheners, a sloping frame, wide
cow-horn bars and was very reminiscent
of the Geoff Apps bike featured in last
month’s magazine. Could this have been
Apps designed? It certainly hooked me
on off-road riding.
Steve Knowles"
http://www.ctc.org.uk/file/member/201011018.pdf
If Geoff Apps did have a hand in designing the Vindec Trekker he has kept it very quiet for all these years.
Whilst its not impossible that Vindec knew of Geoff Apps' early designs it is unlikely.
Apps however, had been riding "Tracker" bikes for years and would have also known about "Cycle Speedway" bikes.
So it's pretty likely that both Vindec and Apps were in some way influenced by the earlier traditions.