Yes, that is to be expected. Under a lighter rider it's likely not a big deal. Under me they flex a lot. I have an old steel touring bike that flexes a lot more. Doesn't really bother me on that bike because that bike has gears. With a fixed or singlespeed I'm up off the saddle a lot more. Pulling up on the bars while standing on the pedals practically at every intersection. I could feel the frame twisting. I don't mind a bit of spring to a frame but torsional flex just feels really weird if you're used to a very stiff ride. My opinion is that clydes are better off with an Al frame but it's just my opinion based on my personal preference and may have nothing to do with this guy. He mentioned that someone said Kilos flex so I related my personal experience. They do flex, how much and whether it's tolerable will depend on the rider. Under a heavy powerful rider on a large frame they flex a lot. For me it wasn't tolerable. Your mileage may vary.