This is an impressive design, and for that they should get credit. They look good and appear to function well. But I have to wonder about some of the reviews I've seen here, because some sound as if they haven't USED the product. The exuberance of some reviews makes me think either I am incredibly unlucky, or maybe Bowflex employees are being encouraged to post comments on the product.
The problem, as others have pointed out, is that these Weight Fitness Equipment dumbbells are not durable. The locking mechanism (upon which the whole system depends) is prone to breaking if you turn the dial with "excessive force" (the term used in the manual when Bowflex warns us how easily this device can break). What's "excessive"? Apparently, it's whatever force you need to turn the dial, which is often sticky. I noticed the locks didn't work properly right out of the box. It took me 1/2 hour to figure out why the weight wouldn't release from the base (the dial often appears to be properly set when the unlocking system is actually not completely lined up). The locks stopped working altogether after the third use.
Weight Fitness Equipment Review - Bowflex SelectTech 552 Dumbbells
Now I can only use the weights if I want to lift 52 lbs per side, with the plastic base still attached. This is unweildy, unsafe, and could only damage the product further, so I don't encourage anyone try using it this way. The question is whether I should seek a replacement or a refund. I'm going to try a replacement this time, and will happily revise this review if I discover the problems were unique to the one I received.
There are other problems also. As many of you might understand, it's common to drop dumbbells to the ground, particularly after a challenging set. But some of the plastic parts on these dumbbells are not strong enough to withstand the sort of use you would expect from almost anyone who planned to use these Weight Fitness Equipment dumbbells as anything more than a doorjamb.
This design is an excellent idea, and the price (+/- $399) is also quite good, IF the product was truly excellent. Unfortunately, Bowflex needs to spend a little more on manufacturing and a little less on marketing. Then this product will be a real 5-star. Until then, the two year warranty is good. But I'm wondering how often I'll bother exchanging over 100 lbs of product before I just ask for my money back.
I plan to try again, this time treating them more like fine china than workout gear. Maybe this will do the trick, but I'm dismayed that I have to work so hard to use a product that is advertised to work for me.