Framebuilders - Frame tubing question

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Supertick
07-18-09, 10:09 PM
Adventure Cycling just came out with a short article regarding the LHT. In the article they state that the LHT is made with heavy 4130 CroMoly steel. I have a MTB (1987 model) that is made with CroMoly Plain gauge MTB frame tubing. Is this the same as 4130 steel? I would like to tour with this MTB if it is up to the task. I had posted this question on the Touring thread but no answers.


sannerbikes700
07-19-09, 12:01 AM
Yes it is. You are probably fine to tour on it.

rodar y rodar
07-19-09, 05:18 AM
I don`t remember whether 4130 is a type of CroMoly or the other way around. Either way, the names are pretty much interchangeable in standard bikespeak. MTBs make dandy tourers.
http://www.bikeforums.net/showthread.php?t=563720
In a similar thread recently, there was an argument put out that straight guage tubing makes for a better tourer than butted- whether that`s true or not I can`t say, but I know I love my touring MTB, which happens to have a plain guage cromo frame.

EDIT: Here`s the technical mumbojumbo- http://en.wikipedia.org/wiki/Cromoly


JohnDThompson
07-19-09, 09:47 AM
"4130" is the ANSI designation for chrome-molybdenum steel alloy; nothing more.

Falanx
07-19-09, 01:53 PM
4130 is the AISI, not ANSI (American Iron and Steel Institute, not American National Standards Institute) for a 0.3% carbon, 1% chromium, 0.25% molybdenum steel. Nothing more. It has become synonimous with 'chomoly' and vice versa the same way hook-and-loop fatsener and the tradename Velcro did. Because people are lazy :-p

Almost all the chromium molybdenum steel used in bicycle frames is, however, 4130 or an equivalent international standard because of its prevalence in tubular aircraft structures. Lots of 4130 gets drawn to a variety of tubing sizes in plain guage - it wasn't too much work to have it redrawn or reshaped into bicycle frames.