Re: ok guys i need info
I run the basic mechanical Avid disk brakes on my mountain bike and they work great.
If I had only one disk brake, I would definitely mount it on the front - especially on a motorized bike.
Your 86 Univega will require a a disk brake fork with a 1" threaded steerer of 6" long or so.
You will also need to get a front wheel that is disk compatible.
My first mountain bike was an 88 Univega Rover. Your Alpina is lighter because it's made with butted steel.
“You're only young once, but you can be immature as long as you like" -Unknown