Bicycle Mechanics - warped sram force crank

Installed a brand new Sram Force compact crank (pretty big bucks) on new bike am building; spider is warped so that the rings are warped as well and lots of chain rub on front derailleur which I can't adjust around. The bike shop folks that sold it to me on Ebay are stand up and will send back to Sram as a warranty item--apparently you have to go through a Sram retailer for warranty problems. Is this an isolated matter or a regular problem with Force? Should I just bail out and go back to Shimano or FSA for a compact crank? My shifters and derailleurs are DA. Thanks.

Usually this indicates shipping damage rather then a manufacturing defect.

Usually this indicates shipping damage rather then a manufacturing defect.

Maybe but if it's the spider that's out of alignment, the shipping damage would have to be extensive and the package would have looked like something drove over it. Crank spiders are pretty strong. I expect it's a manufacturing defect. I haven't heard SRAM has a major problem so it's, hopefully, a rare occurance.

Maybe but if it's the spider that's out of alignment, the shipping damage would have to be extensive and the package would have looked like something drove over it. Crank spiders are pretty strong. I expect it's a manufacturing defect. I haven't heard SRAM has a major problem so it's, hopefully, a rare occurance.

+1.

You're positive it's the spider? If so, both rings will wobble at exactly the same point. If they don't it may be bent rings. This could be shipping damage but, as Hillrider pointed out, the package would show significant damage.

I just returned my SRAM Force crankset through a bike shop. I have put approx 1,200 miles on it and at about 600 I noticed that it was so wobbly that it hit the front derailuer (even after many adjustments). I thought that I bent the large chainring, but after I replaced that it still happened. I have no clue how it happened? I talked to customer service at SRAM and they indicated that they would happily replace it. It did sound like it is somewhat common???

I though that carbon couldn't bend - just break? That is thepoint - stiffness, yet light.

I though that carbon couldn't bend - just break? That is thepoint - stiffness, yet light.
The plastic in which the carbon fibres are embedded can warp after it comes out of the mould. That is why they join the top and bottom sections of FRP boat hulls immediately they come out of their moulds. If they waited a week the parts may not fit together.