I had installed a set of onspot chains on my Ford F350 dump truck in early January. Late January the right canister and bar had to be replaced because it had been bent. Now after the last storm the right bar is bent and most likely needs to replaced. Chain wheel hangs up on shock mount. Installation person states should only be used on smooth hard surface roads. Never heard that from company or read any limitation on web site or in litature. I thought they would be great now not sure. Anyone else not happy with chains?