just a side note

here is what i know about 4130 and mildsteel from the abuse ive given bikes riding bmx and street
low quality bikes at wallmart that u can get for 60 bucks that are made of mildsteel and in a days worth of hard riding i can bend the tubes crack the welds totaly destroy the bike.....on the other hand i only trust 4130 bike frames to take the big hits cause after 20ft high jumps, ,a few roof drops and years later its still holdn up much better then mild steel would and if bends it dosnt "taco" fold into its self as easy as mild steel....only problem it makes a 60 dollar frame cost 200! in short i guess im tryn to say u get what u pay for

 

exactly what I was getting at there!

 

They use mild steel in WRC for its ability to give a lot before it colapses. Many teams are actually using 1 1/2" instead of 1 3/4" because it will bend more.

IIRC a nascrap chassis allows ERW tubing and they want them to fold up in a wreck. The idea is to slow down the deceleration rate to the range our bodies can handle. The point is stiffer isn't always better.

 

Ok, THAT right there was great. All the explanation I needed. Because, I really forgot about that....