Of course, it’s not the purpose of the movie to burnish mountain-biking’s image. But we didn’t want to let its portrayal pass without defending mtb either.

It may be that Aron Ralston, the climber who got himself into a mess in Bluejohn Canyon west of Moab by simply neglecting to tell anyone where he was going, is the kind of guy who:

1. Rides without a helmet. In the movie, James Franco (who by all accounts gives a tour de force performance) is shown cruising across the desert in a baseball-type cap. It may well be that Ralston chose not to wear a helmet. But it’s something almost no mountain biker would do, simply because the risks are so great.

We’ve spent a lot of time riding the hard rock of Utah and can’t remember any time we saw a mountain biker out on the trails without a helmet.

2. Rides an outdated bike. The kind of Rocky Mountain hardtail shown in the film was a decent ride in the 1990s, but mountain bikers in the past decade went almost exclusively to dual suspension. Especially around Canyonlands, where suspension really shines in rugged trail slickrock country.

You do find hardtail holdouts from time to time, and maybe Ralston was one. (The argument for a hardtail is fewer things to go wrong, break down, etc.) The incident took place in 2003, when hardtails still popped up now and then. But we’ve been riding in Moab and vicinity since the early 1990s and by 2000 the scene was mostly full suss.

3. Rides with a backpack better suited to 50-mile hikes than mountain biking. Ralston’s orientation was to rock climbing, so his pack probably reflected that more than biking. No mtber is going to want the big, bulky thing that “127 Hours” shows on his or her back in the southern Utah desert.

4. Rides without gloves and other bike equipment. Again, maybe Ralston did so and the movie is accurate in that regard. But it doesn’t make for a very astute rider in the perilous back country.

5. The header Franco/Ralston takes could’ve been more realistically staged. We’ve seen lots of mountain biking crashes, and been in more than a few ourselves, and this one — where Franco flies off the bike for no apparent reason, having struck nothing or otherwise forced out of control — looks dumb. Franco, or his stunt double, lands neatly on his back. It’s a great way to crash, but hey, you don’t get to select technique when you go off the bars. That’s why all the broken ribs and separated shoulders.

Is any of this really germane to a film which is actually about getting stuck while rock scrambling? Probably not. It also may be the case that the trailer oversimplifies the film itself.

But if you’re a mountain biker watching the film, you may find yourself wincing at its characterization.

To the film’s credit, if everyone comes away from it with greater resolve to tell loved ones where they’re headed the next time they go out on a long ride — well, our other points are just nitpicking.