Why did some bicycles have two top tubes?

Question

http://farm4.static.flickr.com/3085/2650705505_08ba7e5d37.jpg?v=0

I can't think of any reason for making a bicycle like this. It isn't even stylish - it just looks weird. What was the rationale behind the design?

Answer 1

Older frames had a common issue with so called "frame cracking" where rust would gather at the welds causing the frame to weaken. This most commonly occurs on the crossbar (top tube) and was solved (before anti rust paint) by the use of a second crossbar on some bikes. Now, the only common occurrence of frame cracks are on jump bikes (some of which do reinforce their crossbars to create a

triple triangle style of frame) which is caused by trauma such as crashes.

Answer 2

Check this out for strange frame geometry!:

http://img413.imageshack.us/my.php?image...

Answer 3

Extra tube means extra coolness.

I have no idea.

Answer 4

perhaps the welds weren't as strong so it needed two tubes for extra strength

Answer 5

The left one is a spare in case the right one falls off.  Not.  It was just a style fad for a while to get kids to want the newest design.

Answer 6

Well, given that businesses aren't inclined to waste money, presumably one tube was found to be insufficiently strong.