Wheel Flex or (gulp) frame flex?

[crashjames]

While struggling up a local 10% grade I noticed that my speed was scrubbing considerably when I stood to climb the 15% section. It appears that the rear wheel was rubbing against the inside of the left chainstay.

Some specifics:
Wheels are 20/24 Alex 400 laced to WI hubs w/CX Rays.
Bike is a 2002 C-40
I'm a hefty 175lb these days

I hope it's just a matter of re-tensioning the wheel. Could my beloved frame be busted?

[Too Tall]

"....20/24 Alex 400 laced to WI hubs w/CX Rays."

That build is not what I'd call a stiff wheelset but it should not hit your chainstays. Sounds like the tension was not correct.

[ergott]

I bet it's not one single thing. The c-40 stays don't feel as sharp as the Ottrott I had built around the same dimensions. The wheel in question is a good one, but not the best for lateral stiffness. I'm similar to you in weight (180ish) and prefer either 28 spokes for that configuration or heavier gauge spokes.

[thwart]

Bear with me here... but just in case... I've had issues once or twice in the past with rear QR's being clamped just a tad loose, and the very first symptom is chainstay rub out of the saddle. :confused:

[Fixed]

Bear with me here... but just in case... I've had issues once or twice in the past with rear QR's being clamped just a tad loose, and the very first symptom is chainstay rub out of the saddle. :confused:
+1