This is from a touring list I subscribe to. Names and addresses have been removed to protect authors from spam:

Date: Sun, 15 Jun 2003 13:31:58 -0500
Subject: Re: Prominent cyclists

> Well, Jerry Seinfeld always had that nice Klein mtb hanging in his
> 'apartment' on TV. I never saw him ride, but the story I heard was that
> he put bikes in the set so he could write them off as business expenses.
> Since the bikes he put there weren't exactly collector's items, maybe he
> liked to ride. Seems to me I also remember seeing a picture of the
> Material Girl on a bike, though with enough garb on to disguise her
> identity.

Michael Richards ("Kramer") put that bike there. He's a cyclist.
Afterwards, there was a flurry of bike company activity to pay for product
placements on popular TV shows. A Cannondale was placed in Kramer's
apartment, and one appeared in Jerry's apartment as well for a time. One of
the bikes in Jerry's apartment had its fork installed backwards.

Specialized paid to have a bike shop featuring Specialized bikes on the
street that the characters would walk down. It was called the "Special Bike
Shop," and it had all Specialized products in the window. There was also a
Specialized bike in George's apartment for a time.

Specialized also had a Globe in the apartment on Mad About You. A few other
shows had bikes in the background. They were all paid product placements.
One of the most common product placements that you still see today is the
Bose Wave Radio. For a while it seemed that every sitcom character owned
one.

Also, Madonna is a regular cyclist. Sammy Hagar is a big time cyclist and
owns his own shop. Robin Williams rides all the time and is profiled in the
current Bicycling magazine (the first article they had in a long time that I
had any interest in reading).