Noob here to the forums. Just found this site and I have spent more time here than I ought. I am 53 years old and want to start biking again for fun and fitness. Tender knees and tight back have knocked some of the fun out of sports, so biking has been my choice for summer fun.

I want to upgrade my ride from the early 80s Myata hard tail Ridge Runner to something a little easier pedaling. I have been reading and visiting LBS and I am now trying to choose among a Trek 7.3, a GT Tachyon 2 and a Specialized Sirrus Sport.

I will be riding mostly on hard dirt bike paths, some roads, (…but they make me nervous in my middle age…). We have goat head thorns here in Colorado, so some tire modification/supplementation may be required.

i have ridden all three. I like responsiveness of the Tachyon, but being more "roady" seems like a negative. The Trek was nice, meh. But it seemed "sturdier" maybe. The Sirrus seemed more responsive than the Trek, not as much as the Tachyon, and more "bike path comfortable".

What say you all?

Since you are going to be on dirt quite a bit - I'd give serious consideration to the one that will allow the widest tires, and full coverage fenders.

Time to get out the tape, and start measuring clearance on all tires to side and top clearances....

you will thank me, later

Dito your choice in bike and a tyre around 28 to 35c will work.
Since your just getting back into cycling just take it easy and ride with a higher candence or lower gears and take in the sights.
I have a back problem as well it helps to loosen it up.

Thank you for the info. I think I am going to go with the Sirrus Sport. It's mtb-like than roadie, but it still feels responsive. One more test ride, maybe this afternoon and then we'll see.