Join Date: Jul 2007
Location: Northern Colorado
That is too much for that era of Trek 1200. I have a similar bike at home, that I've had since it was new. They have not made those gear parts since the 1980s.
Also, the rear drop-outs are too narrow for modern hubs, and since the frame is Aluminum, you can't just force a wider modern hub in there, without the danger of the frame cracking.
If your rear hub goes bad on a bike from that era, you often end up having to get someone to build you a new wheel around a 126mm hub. A decent build, with parts, for a rear wheel-hub combo around here starts around $220. Modern 135mm width hub/wheel combinations often go on sale starting at $130. Big difference.