Trek road geometry to hybrid?

Tripster said:

I wanted to get my wife a used Trek 1000 and get upright mt bike style
bars - make it into a hybrid. Easier for her back.

Now, are there any issues geometry-wise with doing this? Am I gonna
cause unusual strain because of the combo of road bike/drop bar
geometry and the upright bar combo?

Your bigger problem will be in the brake/shift levers and possible
compatibility issues with derailleurs and brakes. I converted a 7500
from hybrid to road/touring/cross bike and am happy with it, but the
conversion wasn't inexpensive. Consult LBS about compatibility issues.
Probably cheaper to buy hybrid to begin with.

Tripster said:

I wanted to get my wife a used Trek 1000 and get upright mt bike style
bars - make it into a hybrid. Easier for her back.

Now, are there any issues geometry-wise with doing this? Am I gonna
cause unusual strain because of the combo of road bike/drop bar
geometry and the upright bar combo?

You need to pay attention to the length of the top tube and related,
to the length of the stem that you use.

I recently converted an even older Trek road frame to a more upright
position. Instead of a full straight bar, I went with Nitto Moustache
bars. I've found that the more upright posture really wants the bars to be
closer to the saddle than I prefer with dropped bars. Two things to watch
for in terms of the geometry...

1) I think the regular Trek 1000 has a fairly normal (read: longer) top
tube compared to other road bikes that are designed for an upright position
like the 1000C or a touring design.

2) You can udjust the reach to the bars somewhat with using a shorter reach
stem. However, too little reach on the stem can make some bikes feel
squirely. I tried a very short 65mm stem on mine and it was nutty.

A few other loose thoughts....
1) The Nitto Periscopa stem is designed for getting the bars up high and is
relatively short in its reach at 85mm, iirc. Harris Cyclery has them I
think.

2) The 1000 series frames will limit you to 25 c tires. At least that is
what I've found with my 1220 and my wife's 1100, which share the same basic
frame.