It's called "good vibrations", a hard foam tube, $3.00.
In the lawnmower section, comes in black, red, and green.
It's 1' long, I cut mine in half.
It comes pre-slit, with removable contact paper glue stripes on the inside.
It doesn't quite completely wrap a 1 1/8" top tube, but it looks like it does, and it's enough to protect.

Do you have to be 18 to buy one?

why not use foam pipe insulation? appears to be the same stuff. i don't see a reason to pay $3 for a foot of it.

If your parents find it in your room tell them its a back massager!

I looked into that...the pipe insulation at my store came only in 6' lengths, and wasn't pre-slit & pre-glued.

Excuse my ignorance here, but what is the point? My old bmx had something similar, but that was to soften the blow to your nuts when you messed up attempting something stupid yet totally awesome.

Exact same reason. Only since the top tubes are a lot closer to your crotch on a road/track fix, it's even MORE necessary.

fashion.
protect your nuts.
protect your top tube when you lock up.
protect your top tube from swinging bars.

Pipe insulation comes in different diameters so you should be able to get a better fit. It's inexpensive, and does come pre-slit. I use it for shipping bikes.

One more reason for a top tube protector. If your bike has a rattlecan paint job done by seven year olds who haven't ever used spray paint before and the most sever blemish just happens to be on the top tube.

If it's 1' long why did you have to cut it in half?
What exactly are you using it for that is 6" long?

Enjoy

Seatpost cozy.

child labor...you get what you pay for.

paging dolface and his clear pvc...

I'm assuming it's being used to stop the handlebars from hitting the top tube, not for crotch protection. 6" isn't going to much good if you land on the top tube.

i bought some of that 1" inner diameter clear PVC stuff to experiment with, but found that once you cut it lengthwise, it loses enough rigiditiy that it doesn't really wrap well around your tubes.

Keep your top tube from freezing?

No, you've got it backwards. It keeps the top tube nice and cool, very important if you store beer in your tubes.

But if you fall farther you fall harder.

i used this: a single layer of reynolds cling wrap or som'n similar on top tube and /or down tube- then a good tight layer of gaff tape, no gaps, finished off w/ electrical tape nice and tight as well- as a final touch you can sear it just to be sure- ive thought abt the pipe insulation but havent tried it- just lazy- the idear of a little padding just sounds nice on the wallet and the scale tho'...