The July issue of Consumer Reports magazine features two elliptical trainers that testers found to be safety risks. We judged both models—the Stamina 1725 and similar Stamina 1772—"Don't Buy: Safety Risk," a new designation.

The problem: Bolts attaching the pedal arm to the drive-wheel assembly loosened, and came off in one instance. That put the user at risk of losing balance and possibly falling.

In late April, our Technical Division told Stamina officials about our findings. Stamina said it was aware of the issue and had updated its manual to instruct users to tighten the bolts before each use, an instruction we consider unrealistic. If you have one of those machines, stop using it immediately and notify the company at 800-375-7520 if you've had a problem.

The designation "Don't buy: Safety risk" replaces the label "Not Acceptable" that we used for many years to alert readers to models with safety risks. In addition we introduced the designation "Don't buy: Performance problem" to replace the "Not Recommended" label formerly used for models with serious performance problems. We will be using the new designations—marked with a yellow icon—in the magazine and on the Web site.

For more information on ellipticals, read our Buying Guide (with Ratings for subscribers).