# chromoly vs aluminum vs hi-ten



## Qubo_2408 (Dec 31, 2011)

I'm looking to get a 24" cruiser for mostly dj and urban/street riding. I'm 250lbs. Now I'm 95% sure I need chromoly for the strength. But I've been looking for used ones do to my limited budget and keep finding only finding 6061 alumimum and hi-ten. And I've got a couple I could buy but I'm scared to snap the frame. I don't need a big explanation or debate just some one to tell me to keep being patient or not to be worried and just pull the trigger.


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## iperov (Sep 9, 2012)

bamboo win!


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## jmmUT (Sep 15, 2008)

Short answer: Don't do hi-ten, aluminum OK

Long answer: Aluminum (as long as not really old) will be strong enough and stiffer than chromoly. I would avoid hi-ten (hi-tensile steel) as it's definitely weaker. But chromoly is becoming cheaper and cheaper. It's also important to watch for is what the bike is intended for. If it's a race bike regardless of material it will be weaker than one built for DJ/street. Geometry will be different too-such as longer chainstay which makes manuals and bunny hops slightly harder.


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## Ganze (Feb 3, 2004)

what they said: no used aluminum, no hi tens steel.

I am a big boy too: chromoly steel is the lowest quality that I would consider. But chromoly is great and I have several bikes made from it. Reynolds 525 and up, True Temper tubes, Dedacii, and other high end steels are even better in that they can be made into a lighter frame with the same strength as 4130 chromoly. 

Aluminum breaks as it bends, steel, even high tensile bends before it breaks. I have choppered my share of forks. Those same forks in aluminum would have resulted in catastrophic failure. Aluminum also has a finite fatigue life which means that if you use it long enough, it will fail. Most aluminum frames and parts are so over-built that most riders will never approach that fatigue life. But with imminent failure in mind plus my size; I have retired quite a few sets of forks, bars, posts and other parts after a few years of hard usage. All that being said about aluminum breaking and steel bending doesn't account for poor quality welds on steel bikes.

I ride steel (chromoly) cranks, bar, seatpost on high end steel frames exclusively. Being big makes it even more important for me to get the security of non-catastrophic failure.

g


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## 89redranger (Oct 6, 2012)

From what I know when I rode BMX, alloy frames are the sh!t for race bikes (more stiffness for gate starts and such), chromo sucks up the bumps a little better for trail/park bikes, and hi-ten shouldn't ever leave the ground. How that fits the MTB world I still have yet to find out. I'm searching for a chromo bike myself. Then again, I'm also planning on riding a rigid fork...


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## GiantMountainTroll (Mar 27, 2012)

chromo ftw


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## chain_slap (Aug 28, 2008)

Chromo bends before it breaks, aluminum snaps, most aluminum cruisers are race bikes, go chromo if your dirt jumping and going big. High-ten isn't so bad for flatland and street, but if I was a big boy I would trust a full chromo frame and fork over aluminum and high-ten.


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## manual63 (Nov 5, 2006)

Here is the scoop......from someone who has been riding BMX and DJs since 1980 and still rides hard just about every day!

Hi-Ten: Don't do it......just too heavy and well, it's not nearly as strong.

Aluminum: Aluminum is stiffer only because the tubing diameter is bigger and companies put on a bunch of added gussets. Aluminum is not naturally stiffer than Chromoly or any steel for that matter. An aluminum frame has to be beefed up so much in order to be strong enough for riding, it ends up not being any lighter than a good Chromoly frame. Aluminum has a higher catastrophic failure rate.....this simply means that when it fails it fails hard and fast with no warning. At your weight....for a jumping bike.....no way!!!

Chromoly: It is all around the best material for what you want to use it for. Be patient.......wait it out. If you look at what is happening, many companies that used to use Aluminum DJ frames are starting to use Chromoly now. It's just as light and a LOT STRONGER than aluminum. Another thing with Chromoly........when/if it is going to break....it usually gives you plenty of signs and warnings, as long as you inspect your frame once in awhile. It rarely just fails without warning.

I recently wrote a few articles targeted for BMX racers that you might want to read.

Why do BMX racers think aluminum is a better frame material? | f-bom bikes

Why do racers think aluminum is a better frame material? - Part 2 | f-bom bikes

Kicking the Steel is Heavy Myth | f-bom bikes


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## manual63 (Nov 5, 2006)

Oh......and bummer you are looking for a 24" because I now have an Eastern Night Train frame for sale since I replaced the frame with my new f-bom bikes frame.

The Night Train is Chromoly and pretty decent.


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## NEPMTBA (Apr 7, 2007)

manual63 said:


> Here is the scoop......


^ What he said!:thumbsup:


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