Low movie expectations can be as helpful at this time of year as lip balm. I thought ''Shanghai Noon'' was slow on the draw when it was released in the summer of 2000, a comedy more ''Mild West'' than ''Wild,'' despite the exertions of its cuckoo-cowboy stars, Jackie Chan and Owen Wilson. Yet coated by a seasonal, waxy barrier against chapping, I took in Shanghai Knights with lips unforced in a smile of indulgence. This is an action-comedy sequel so indefatigably preposterous and farklemt -- as they say in certain Upper West Side saloons -- that it actually improves on the original.
And it does so by upping the genre jingle jangle. Chon Wang (Chan) and Roy O'Bannon (Wilson) went their separate ways at the end of ''Noon'' -- Chon to keep the law as sheriff of Carson City, Nev., through a combination of high ideals and superior acrobatic skills, Roy to live the high life in late-19th-century New York City through a combination of drawling charm and late-20th-century-style moral corner cutting. Now the two reunite to avenge Chon's father's murder back in Shanghai, a mission that takes the pair to Victorian London, where their acquaintances include Jack the Ripper, Arthur Conan Doyle, and Queen Victoria. Chon's lithe sister (Singapore star Fann Wong) is introduced to fill the now popular role of girl-who-can-kick. Lord Rathbone, a sinister British meanie behind the murder, is fun to watch if only for the odd thrill of seeing the striking Irish actor Aidan Gillen ditch his reputation as the snake-cold star of the BBC's ''Queer as Folk'' for that of a sneering action-flick baddie. ''Blade II'''s Donnie Yen plays Rathbone's even more villainous Chinese-rebel cohort. Plot, as usual, is convoluted, and the least of the movie's concerns: Banter and comedic riffs, interspersed by explosions of martial artistry, are what matter. And in this, ''Shanghai Knights'' benefits from familiarity -- and necessity.
Having already established their chemistry, Chan and Wilson don't have to work quite so hard (with the noisy effort that dragged down the original) to convince us of the fun in their partnership. There's less emphasis on (or need for) drollery based on cultural differences between the two men, less time wasted with jokes dependent on bad pronunciation (Chon's) or bad attitude (Roy's). And thus freed, screenwriters Alfred Gough and Miles Millar (who also wrote ''Shanghai Noon'' and created TV's ''Smallville'') find passing amusement in a jumble of silly stuff, much of it British-based. There's the required contemplation of the local pudding unimprovably named Spotted Dick, of course; there's also ribbing of the conventions of Sherlock Holmes mysteries, the implacability of Buckingham Palace guards, the pomp of royal events, and the identifiability of Stonehenge. (One joke left unturned by cinematographer Adrian Biddle, veteran of ''The Butcher Boy'' and ''The Princess Bride'': This movie-set London is played by Prague.)
Gough, Millar, and commercial-and-video-seasoned director David Dobkin also elicit some rec-room laughs referencing the comedy influences that have shaped Chan's style and, to a lesser degree, Wilson's as well. A clutch of uniformed policemen in a hapless kerfuffle is Keystone Kops all the way; a perilous moment hanging from the hands of Big Ben is rooted in the repertory of Harold Lloyd; a who's-where mix-up involving a trapdoor that revolves between rooms is a setup made for Abbott and Costello. Some deadpan chat before the two jump into a river is the province of ''Butch Cassidy and the Sundance Kid'' (which Wilson appears to have studied). And an elegant fight scene in which Chan's only weapon is an umbrella is so identified with Gene Kelly that the soundtrack directly plinks out the opening measures of ''Singin' in the Rain.''
Which brings up invention born of necessity and the pull of gravity on the aging bones of extreme-action stars like the savvy showman Jackie Chan. ''You little Chinese otter,'' Roy coos at his partner, yet Chan is really a fox, sly about how to suggest more than he actually shows of his own athletic prowess. Much of ''Shanghai Knights,'' in fact, is focused on close-ups of the stars' Silly Putty faces -- those mighty schnozzes! -- and not on their Lego bodies, stacked and snapped into gaily outlandish mail-order cowboy costumes. And then, when the kicking, spinning, and blocking does take over, the camera pulls back so that it's usually the whole blurred tableau we see, not the details of Chan's characteristically playful choreography.
In place of darting and leaping moves, Jackie Chan is now perfecting a stay-put style no less inventive in its construction. In place of a younger man's gymnastics, he favors mature brain work, expressed in dazzling strategy showdowns involving everything from ceramic vases (that must be kept from dropping and breaking) to revolving doors and library ladders. His is a talent not so much cooling down as getting cool in middle age. And, it turns out, his is just the right temperature for light entertainment on a long winter's movie night.