Can't say what you're asking about here, as BMX bikes aren't used in a velodrome.
5 years
It took approximately 6 years to build the London Eye.
the olympics are on for 1 month in the summer in england london 2012
balls
250 meters uci
About one year.
How long did it take to build st James cathedral london
July 27 2012 until August 12 2012
1886 to 1894
1886 to 1894
Eight years
About six years.