Steven M. Scharf

Steven M Scharf (who now posts as SMS) describes himself as one of the world's leading authorities on bicycle lighting, and bicycle helmets, and various other things. Fortunately the world carries on in blissful ignorance of this fact, since it has been established that his "expertise" is based on religious conviction rather than evidence.

Background
There are two main hot topics with Scharf: lighting and helmets.

Lights
He has a website on which he proclaims himself to be one of the world's foremost experts on bicycle lighting. On this site he expounds his view that only the very brightest battery-powered halogen lights are safe to use. He is not prepared to accept that dynamo powered lights are adequate for any cyclist. Needless to say, those of us who use dynamo powered lights find this assertion to be problematic. Countries like Holland and Germany, with much better cycle safety records than the USA, are big markets for dynamo lighting. Scharf has dropped the occasional clanger in his spirited defence of very bright lights:
 * He stated as fact that the side-facing LEDs of the Cateye TL-1000 were a significant benefit in preventing side impacts.  These LEDs are at most 0.2W apiece, very far below the minimum which Scharf says is required for safety in a rear light.
 * He stated that MR-series halogen lamps are used in car headlights. They aren't.  Rotationally symmetrical lamps are not used in OEM applications by car makers; like the makers of dynamo headlights, they use optics to focus and place the light for best effect.  The lamps he saw were add-ons sold to chavs for pimping their rides, not OEM lamps.

Scharf does know a fair bit about battery lighting, but he confuses his opinion with fact and is utterly unable to accept that his experience or is opinion may not apply universally. I have yet to see him use any qualifying terms such as "in my view" or "I believe" when rendering his opinion. He is an expert, he thinks X, thereofre we must accept X based on his word alone, and how dare we challenge him to provide some evidential basis for it?

Helmets
Scharf waded into a helmet thread with his usual mix of dogma and cluelessness. He has decreed that calling into question the efficacy of helmets is not the right way to fight helmet laws (although he has never fought off a helmet law, whereas his opponents in this argument have). Nor may we suggest that cycling is not dangerous. The only permitted argument, according to Scharf, is libertarian.

As a helmet thread participant, Scharf is ignorable. He makes it clear by his every word that he has no understanding whatsoever of the research evidence - for or against - and his sole contribution is essentially sniping form the sidelines, cheered on by the usual crowd.

Modus Operandi
Scharf will join any thread on one of his hot topics. He will make dogmatic assertions of his opinion as if they were immutable fact, and will never cite the evidential basis for them. The few pieces of evidence he has cited, he shows no sign of having read or understood.

He will argue the toss for a while, then take the argument to his website where he can make his assertions without the relentless debunking and factual corrections they receive on Usenet.

Scharf will also consistently ignore any arguments which refute his assertions, and will continue repeating the assertion as if no rebuttal has been made.

Finally, he will accuse others of his own worst faults, such as this post in which he says that "Facts, science, and logic have no place in the world of the AHZ's." (AHZ - "anti-helmet zealot" - is Scharf's term for anyone who dares to question the efficacy of helmets). Scharf has, I think, cited one or two studies at most in all the helmet threads in which he's been involved, and in no case has he shown any evidence of actually having read any of the evidence in detail. By contrast his main opponent in these debates, Frank Krygowski, shows a comprehensive knowledge of helmet evidence. Accusing others of his own faults is a repeated feature of Scharf's approach.

How to deal with Scharf
Check all dogmatic assertions made by him, probe for the evidential basis, cite conflicting evidence and challenge him to cite the evidence in support for his position. Do this enough and he will killfile you.