Consistent with the holding in Bust, supra, we will not condone a rule that would imply the existence of a defect whenever it is established that a product could feasibly be made safer. Unfiltered cigarettes, for example, are not defective simply because filtered cigarettes might be less dangerous to the consumer. In our view, the “unreasonably dangerous” requirement serves the useful function of balancing safety considerations against a policy which favors product diversity and consumer choice. Automobiles, and numerous other types of products, vary considerably in their safety features and characteristics. However, the law does not require that manufacturers produce only the safest product feasible in order to avoid being exposed to liability. Rather it requires them to avoid placing on the market products that are rendered “unreasonably dangerous” because of a defect in design or manufacture.
The cases cited by plaintiffs do not support their contention. Union Supply Co. v. Pust, supra, involved an industrial accident in which the element of consumer choice was not present. Further, although the defect complained of may have been readily apparent, the extent of the danger might not have been fully anticipated by the ordinary user of the product. In Roberts v. May, supra, the specific risk of harm complained of was neither fully apparent nor within the contemplation of the ordinary consumer.
For the same reason, we reject plaintiffs’ contention that the motorcycle was in a “defective condition unreasonably dangerous” because the defendants failed to warn the plaintiffs of the risk of harm of driving a motorcycle without crash bars or leg protection devices. Since the specific risk of harm complained of was fully apparent, widely known, and commonly recognized and would have been anticipated by the ordinary user or consumer, no warning was required. See Bookout v. Victor Comptometer Corp., supra; CJI-Civ.2d 14:20 (1980).
We also reject plaintiffs’ contention that the motorcycle was defective because the defendants failed to advise them of the feasibility of reducing the risk of harm in the event of a collision by installing crash bars. We know of no authority imposing a duty on a manufacturer to advise a consumer of feasible alternatives that might render a product safer. Obviously, under certain circumstances, the existence of a feasible alternative is relevant to determining whether a product is defective. However, where, as here, the product is not unreasonably dangerous because of a defect, then strict liability may not be imposed on a manufacturer for failing to advise of some feasible alternative that might have rendered the product safer. See Curtis v. General Motors Corp., supra.
Plaintiffs further contend that the question of whether the defendants were negligent or breached an implied warranty in failing to offer crash bars or leg protection devices as optional equipment should have been submitted to the jury. We disagree.
In any products liability case, regardless of whether recovery is sought under a theory of strict liability, negligence, or breach of an implied warranty, in order to impose liability on the manufacturer of a product, the complaining party must establish that the product causing the injury or damage was unreasonably dangerous because of a defect. See W. Prosser, Torts § 103 (4th ed. 1971); R. Hursh & H. Bailey, American Law of Products Liability 2d § 1:7 (1974). However, we are aware of no authority which would impose a duty on manufacturers to offer all feasible safety devices as optional equipment, and we decline to adopt such a rule here.
The existence of a duty is a threshold question of law for the court, not a fact question for the jury. Metropolitan Gas Repair Service, Inc. v. Kulik, 621 P.2d 813 (Colo.1980); Leppke v. Segura, 632 P.2d 1057 (Colo.App.1981). Inasmuch as we have concluded that the trial court here was correct in finding that, as a matter of law, there was no such duty, we hold that