So, from my research on Diamondback MTBs, it seems they came out with the Ridge Runner in 82/83.
In 1984, DB had a small line of MTBs with various "Streak" names.. the Ridge Runner was renamed the "Mean Streak" and the Trail Streak and Sand Streak were also offered. (see 1984 Diamondback Catalog
I'm pretty sure the Apex and Ascent were added in 1986. I have an early Apex which was manufactured in late 1985 and I suspect was offered as a 1986 model based on the review of the Apex in Mountain bike magazine in early 1986
So this leaves me wondering about the line up for 85.. was it more of the "Streak" bikes?
Looks like the Arrival (aluminum) frame was introduced in 1987. I think the Ascent EX was first offered that year too. Here's the line up and specs from 1987
I think the Axis was added in 88. I wish I could find an Axis around here! Here's a real nice 1988 catalog
And to round out the decade, the 1989 catalog
can be found right here on Retrobike thanks to Frotz. Looks like the Axis Team was the high end bike of the year. Something unique about 1989 is the higher end models all have straight tapered forks.
It seems like DB kept this basic naming scheme into the 90s, adding more variations of the higher end models and also adding the Response line of suspension bikes.
Any info on the early 80s thru 86 would be really appreciated