In many cases, stems, seatposts, platform pedals and other super-rudimentary components are good candidates for generic labels -- depending on your needs, they can be a great way to shave bucks off your budget.
Clipless pedals, though, are an area where you should be a touch more careful. How well a clipless pedal functions depends on the quality of the design (generic models are generally clones of Shimano or Look designs), as well as the quality of the construction and the materials used -- and the poorer the function of those mechanisms, the greater the chance you run into serious problems with ergonomics and safety.
A well-designed pedal, in addition to being reasonable in weight, should offer the following to satisfactory degrees:
- Ease of entry. How tricky is it to find the mechanism with your foot, and once you're there, is engaging the clip a clean action? Or is it overly resistant, tough to predict, or sloppy-feeling?
- Security. Once you're engaged, does the pedal permit you to perform normal maneuvers without fear of popping out?
- Ease of exit. Is there a deliberate, simple and ergonomically sound way to get your foot out, quickly, when needed?
- Float, and other ergonomic issues. Does the pedal permit your body to move naturally, or is it restricting your biomechanics in some way? Most modern pedals offer some level of "float," or rotational ability -- imagine your foot pivoting left and right on the pedal. For most people, some float is essential to knee and leg comfort. Some systems, like old SPD formats, offer very little, and many self-center themselves with stiff spring-action. Others, like Speedplay, make wide, free-float a priority. A few models (Time comes to mind) offer some lateral float.
The size of the "platform" is often debated as well -- arguably, a supportive design will see your sole fixed to a large, long total unit when the pedal is engaged. Most contemporary road models satisfy this concern.
Ok, back to generics. Most of the house-models from Nashbar, Performance, Supergo and the like simply aren't the best at providing the above standards -- well, at least. Most, including those built into full-sized platforms, utilize a simplified Shimano SPD variant, and don't do it too well.
I'm generalizing here, because these stores sell a wide-range of house-branded pedals, but expect ease of entry, ease of exit, security and float to be a touch sketchy with many examples.
They're great as a low-cost, all-purpose solution for that commuter-bike, or that around-town beater or light trail rig, but if you're regularly doing longer rides, you might want to consider investing a tad more in a better model...
Good luck!
