Okay guys.. you are going to go out in the bush for some fun trail riding.
Your buddy’s might be riding newer technology bikes.

You can pick Any pre 1990 bike.

What do you choose!

76 dt 400 with air assist forks and 7.5 weight fork oil and any shocks with an inch more travel and the right springs. take extra gas or plan gas stops as mine only gets about 55 miles from a tank
doug

Modified 69’ - 70’ - 71’ CT1, 175cc, mx carb. webco head, 74’ mx rear concave sprocket and a sleeper pipe.

a

I'll get back to ya after Bultaco is done, right now DT360

Hands down, CT1. Best power to weight ratio and great frame geometry, no yama hop. Curtis I want my bike back.
Capt Dave

250A

For off road only trail riding my personal favorite is my 1976 1/2 Husqvarna 250CR. Super light (weighs in just over 200 lbs), very quick with good power range and excellent suspension (even with only about 7.5 inches travel). Short enough that I can touch the ground with both feet when stopped.

For trail riding that would require a "street legal" bike I would take a later DT175 or DT200 with front disc brake. That's a little bit of a problem in the USA because we didn't get either so I'm working on building my own.

If I didn't care about touching the ground or street legal any of the 1980's IT Yamahas would be great.

A little newer street legal option would be the Honda CRM250 or CRM250AR two stroke... but you'd have to change your rule to "before 2000"... the Honda CRM might be the ultimate street legal trail bike but wasn't available in North America so not easy to find here. I can touch the ground with both feet on this bike too. If "before 2000" and not street legal I'd love a Yamaha WR200.

The theme for me is that the lighter bikes are a lot more fun on the trails. And being able to touch the ground with both feet is awesome.

A couple of years ago I bought a new Yamaha XT250 mostly for the fuel range... around here you need to be able to go 100+ miles minimum for most trails. The new XT has very "1980's" suspension... except WAY too soft. After some suspension work I've taken my XT on many rides with "modern" bikes. At first, I got a lot of crap about my little XT... especially from the sea of "team orange" bikes in the local meetup group. After I was able to keep up pretty good the negative comments slowed... After we ran Rocky Gap road and all the "tall bikes" fell over (often repeatedly) in the section of about a mile of very rough boulder-strewn terrain... and I was able to ride through unscathed and ended up walking back to help the fallen riders... the teasing about my XT stopped. I'm not a great rider at all... but when the going gets rough a smaller bike that is easy to get a foot down is a great equalizer! Like I said the new XT250 is very "1980's" in many ways so I think a pre-1990 bike can certainly compete on the trails with the modern bikes...

If I picked from my current collection it would be my CT1, and I wouldn't expect them to ride my slower pace.
If I picked from bikes of my past, it would be my XR250. (Michigan trails are carved thru the trees and that bike was a blast to ride in the woods)
If I were to pick from other bikes I've been on, it would be my buddies beautifully restored Elsinore.

78 DT400 with an extra gallon of gas attached if going on a longer ride. It's got all the suspension I need and more power than I should be turned loose with. And I can touch the ground with both feet and my Butt doesn't go numb.

All,
My 'daily rider' RT-3, with .005 milled off head, Boyesen Reeds, Sleeper Pipe, Barnett racing clutch and springs (needed with the Sleeper Pipe), DEET clutch actuator mod, Red Wing 'hammerhead' shocks, forks with S&W springs and good old BelRay fork oil. Rides well with 7.5" up front and 5" in back, lugs down and you CAN'T stall it. Plus, it'll do a constant 70 mph on the freeway (as my jaunts from Santee to the Border at San Ysidro for work can attest. Alas, it gets crappy fuel mileage of about 23 mpg, but you can't measure the GRINS per mile!
Hammer