Define a "racing bike"

[mjr]

IMO it's an expression used by those who know very little about bikes or cycling to refer to a bike with skinny tyres and drop bars.

Or by us children of the 1970s who sometimes forget the language zealots have banned the phrase

 

[Illaveago]

The closest I can find at the moment is a 1950's advert for a BSA Tour of Britain Sports in which it states that it has racing hubs and racing tyres.

 

[mustang1]

- and strictly speaking if a bike is to be used for racing it must conform to the British Cycling https://www.britishcycling.org.uk/article/bcst_rulebook_and_constitution and UCI regs:
http://www.uci.ch/inside-uci/rules-and-regulations/equipment-165067/

But that is for racing officially sanctioned events. You could have a club race, a race amongst friends and so on. I think that's why OP left the question open ended and there are so many different answers. Not saying you're wrong, just saying there are other types of race too!

 

[w00hoo_kent]

Or by us children of the 1970s who sometimes forget the language zealots have banned the phrase

Yeah, I want to differentiate my Synapse from my Sirrus to someone who doesn't know bikes, I naturally just say 'I've got a racer' and presume they are also 45 so know perfectly well what I mean.

Everyone knows there are four basic types of bikes - Racer, Shopper, Chopper, BMX. Everything else is just a tweak on one of those. :-)

 

[Illaveago]

Things were a lot simpler in the 60s, there weren't so many different types of cycles around. What we assumed or what we were told was a racing bike is like my avatar picture. It may have been a tourer, roadster or lightweight,it looked similar to what cyclists used in the Milk Race, this myth would no doubt have been exploited by marketing people to help sell their product. It might not have had Team Banana stickers on it but it had drop handle bars, a skinny saddle, and lots of gears.
We raced one another on various machines as schoolboys do, Raleigh Ladies cycles with fully enclosed chain guards, newspaper round bikes both of which weighed a ton and soon disappeared into the distance backwards.
We also modified our bikes for dirt track racing, removing chain guards and all unnecessary bits, fitting knobbly tyres and some extremists even fitted Cow Horn handlebars.

 

[tyred]

I'm going to put drop bars and skinny tyres on a Raleigh Chopper. Can I call it a racer?

 

[Illaveago]

Good idea you might start a new trend.

 

[TheSoulReaver03]

A racing bike is a bike whose frame and build is designed for maximum aerodynamics and speed, often times sacrificing comfort for it.

 

[tyred]

If I did my Chopper drop bar conversion, the riding position would certainly be low enough to cause discomfort!

 

[youngoldbloke]

I'm going to put drop bars and skinny tyres on a Raleigh Chopper. Can I call it a racer?

No need for the drops and skinny tyres - see http://www.cyclingweekly.co.uk/news/latest-news/chopper-charity-rider-causes-bemusement-on-tour-de-france-mountains-185788

 

[Scotchlovingcylist]

I suppose its a bit like people who say their 'training' but not actually training for anything in particular
You might buy a road bike and refer to it as a racer without ever racing it

 

[w00hoo_kent]

If I did my Chopper drop bar conversion, the riding position would certainly be low enough to cause discomfort!

Definitely if it has the original gear shifter...