# Cro-mo vs aluminum



## giantrider9 (Sep 3, 2006)

Whats the difference?


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## namaSSte (Dec 19, 2003)

giantrider9 said:


> Whats the difference?


ummmm, they are different kinds of metals. crom-mo is a steel alloy and tends to be preferred by those that favor strength and durabilty over weight. there are exceptions of course but generally speaking this is the case. in addition, crom-mo doesn't tend to have a "shelf life" like aluminum does.

not sure this answers your question at all so give some more info if not. fyi, my bmx and park bike are both steel, my trail bike and roadie are both alu. different metals for different applications.


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## giantrider9 (Sep 3, 2006)

My abd i didnt explain at all, what i meant was would it be better to have a cro mo bike for urban/dj/light freeride kinda stuff or would aluminum be a better option. Also, which one is more durable and will last the lognest and take abuse the best?


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## ServeEm (Jun 15, 2005)

namaSSte said:


> in addition, crom-mo doesn't tend to have a "shelf life" like aluminum does.


What do you mean? Are you saying Alum has a longer shelf life? Doesn't alum alloys fatigue a lot faster than steel?


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## the_godfather (Jan 19, 2007)

cro-mo will potentially last pretty much forever if looked after well. Cromo will take the most abuse repeatedly. Alluminium is lighter and usually stiffer (depends on build quaility) and will generally be more expensive for a high quality one as the welding process for alluminium can become quite expensive due to heat treatment etc.


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## captain spaulding (May 7, 2006)

ServeEm said:


> What do you mean? Are you saying Alum has a longer shelf life? Doesn't alum alloys fatigue a lot faster than steel?


You're reading into it too much he's saying.. Cro-Mo doesn't have a shelf-life but aluminum does, meaning Cro-Mo lasts forever and alumminum can/will break.. get it?


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## TXneedmountain (Feb 14, 2007)

giantrider9 said:


> My abd i didnt explain at all, what i meant was would it be better to have a cro mo bike for urban/dj/light freeride kinda stuff or would aluminum be a better option. Also, which one is more durable and will last the lognest and take abuse the best?


Between those two it would pretty much definetly be Cro Mo, IMO. Though Steel is also another excellent choice for DJ/Urban


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## womble (Sep 8, 2006)

Are good bikes actually made from chr-mo? I thought that was an alloy department store bikes.

Anyway, basing a bike choice purely on material is kind of pointless. Design and build quality are more important considerations.


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## snaky69 (Mar 8, 2005)

TXneedmountain said:


> Between those two it would pretty much definetly be Cro Mo, IMO. Though Steel is also another excellent choice for DJ/Urban


You are aware that Cro-Mo is a steel alloy, which makes it steel, right?

Which will last longer? Hard to say, two very well built frames, one of each material can last a very long time, but aluminum will tend to break due to fatigue much earlier than steel will. Steel also has a tendency to bend rather than break, and usually shows sign of fatigue before it does. Aluminum will crack or snap.

Steel is heavier, but it absorbs vibration better and can make for a smoother ride.

Aluminum is lighter and stiffer, but you'll feel everything on the trail or jumps or whatever it is you're riding.


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## TXneedmountain (Feb 14, 2007)

haha whoops I forgot about that even though I read that right in this thread.


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## snaky69 (Mar 8, 2005)

womble said:


> Are good bikes actually made from chr-mo? I thought that was an alloy department store bikes.
> 
> Anyway, basing a bike choice purely on material is kind of pointless. Design and build quality are more important considerations.


Yes, my frame is made out of true temper ox platinum steel, which an air hardening heat loving 4130(cro-mo) alloy.

Departement store bikes on the other hand are usually made from crappy high tensile steel, which is heavier and weaker and much cheaper.


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## the_godfather (Jan 19, 2007)

no. good bikes are usually made from alluminium as they will be lighter. most pro's will use alluminium or even titanium as it doesn't matter too much about the fatigue life as they will probably get a new bike each year which is paid for by sponsers, not by themselves. therefore durability isn't really taken into consideration like it would be with 'common' person bikes who have to pay for their bike components


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## snaky69 (Mar 8, 2005)

the_godfather said:


> no. good bikes are usually made from alluminium as they will be lighter. most pro's will use alluminium or even titanium as it doesn't matter too much about the fatigue life as they will probably get a new bike each year which is paid for by sponsers, not by themselves. therefore durability isn't really taken into consideration like it would be with 'common' person bikes who have to pay for their bike components


I take it my Nemesis Project isn't a good bike then? There definitely ARE good bikes made from Steel.

Nemesis Project, Tonic Fab, Dobermann, USB, Transition ToP, Black Market, Atomlab, etc...


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## GotMojo? (Mar 25, 2004)

Steel is real! 

All my bikes are steel except my Kona. I really like the feel of a steel frame, and hope to replace the Kona with a steel frame at some point, maybe a Transition T-o-P or something like that.


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## giantrider9 (Sep 3, 2006)

How much heavier are we talking about with a cro-mo frame? Im asking all of these questions becasue im thinking about ditching my GF Opie (a pos bike component wise, but a sweet frame) and getting a P1 which is cro-mo. WIll the singlespeed make up for the weight gain and both the Opie and the P1 will be about the same weight?

Also, if anyone has ridden or owns the '07 P1, please tell me about how it rides and our opinion on it.


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## jamesdc (Oct 31, 2005)

All my bikes are chromoly steel frames, my dh, dj, and bmx. Chromoly frames are the only way to go.


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## robscomputer (Mar 21, 2005)

I think it's more personal perference. Some people ride very hard and rather have a heavier frame for the trade off of more strength. While others are smooth and use alloy that is lighter but not as strong. If a frame is built correctly, steel and alloy will be just as strong but in the long run, I believe steel will last longer just since it's better with dings and grinding.

Steel flexes more than aluminum, and this will produce less cracks. Aluminum is very stiff and instead of flexing will crack. This is not to say all aluminum frames will crack, or steel frames will not, but just an example of the different materials used. Also on the bmx world, street and ramp guys almost all ride steel where as racer's ride a lot of aluminum. 

I been riding a aluminum bike for a few years and just ordered a steel bike. I'm interested to see if I notice a big difference betwen the two frames. 

Rob


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## ServeEm (Jun 15, 2005)

jamesdc said:


> All my bikes are chromoly steel frames, my dh, dj, and bmx. Chromoly frames are the only way to go.


What DH frame do you have? How much does it weigh?


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## snaky69 (Mar 8, 2005)

giantrider9 said:


> How much heavier are we talking about with a cro-mo frame? Im asking all of these questions becasue im thinking about ditching my GF Opie (a pos bike component wise, but a sweet frame) and getting a P1 which is cro-mo. WIll the singlespeed make up for the weight gain and both the Opie and the P1 will be about the same weight?
> 
> Also, if anyone has ridden or owns the '07 P1, please tell me about how it rides and our opinion on it.


You won't notice the weight, the Gf's geometry is crap compared to the P's IMO.


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## Vinny A (Oct 8, 2006)

the_godfather said:


> no. good bikes are usually made from alluminium as they will be lighter.


Dude, do you know what you are talking about at all? Every single street BMX frame is pure cromo, with the exception of the Ti Reaper... so by your logic every street BMX frame is a bad frame. What about NemPro, Tonic Fab, Dobemann, BlkMrkt, Atomlab, USB are they all bad frames too?

Sh!t Ian, Brad is ripping people off his frames are steel they suck!


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## snaky69 (Mar 8, 2005)

Vinny A said:


> Sh!t Ian, Brad is ripping people off his frames are steel they suck!


Damn it, I need to get my money back then:thumbsup:


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## jamesdc (Oct 31, 2005)

ServeEm said:


> What DH frame do you have? How much does it weigh?


I have an swd 216 frame, it weighs a little over 9 pounds with no shock.


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## mack-a-nator (Apr 26, 2006)

ive got a kona scrap for dj/dh which is alum and used to ride it for street, it worked fine but i recently switched over to my hutch bmx which is cr-mo and it is a great ride, i think the steel works way better for street, on thursday i will be ordering a stolen wrap to replace the hutch so i dont do anything to mess that up. i guess its just all personal preference


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## TXneedmountain (Feb 14, 2007)

Quick question if the frame has a small ding in it is the bike still structurally strong and last from abuse?


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## Vinny A (Oct 8, 2006)

It will be fine, no need to worry about it.


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## transitioned (Apr 13, 2007)

*-= Recommended Reading =-*

Answer to all your questions here.

Pretty interesting stuff.

Generally speaking Cro-mo is the way to go for Urban/DJ/Park.


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## sittingduck (Apr 26, 2005)

Except for the ones I've sold before they broke, or the ones I'm riding now, I've broken every frame I've ridden. Steel, aluminum, it doesn't really matter, they ALL break. Theoretically, aluminum does fatigue a lot faster than steel, but it's also a lot stronger pound for pound. Find a frame with a good track record, and the geometry you like, and ride it.


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## Formerbmx37 (Apr 7, 2007)

I had a steel frame and an aluminum frame that were both bmx and when i dinged the steel frame it was fine and i still have it to this day but got a dent in the aluminum frame and my next crash it tore like a soda can. I think it all depends on how smooth you are if you are confident and ride smooth aluminum shoud be great but if you plan on crashing and breaking bone id go with chro mo or steel


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## dlroto (Sep 10, 2006)

I have a 2005 cannondale chase 2 what is it made of???


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## snaky69 (Mar 8, 2005)

dlroto said:


> I have a 2005 cannondale chase 2 what is it made of???


Aluminum.


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## aggiebiker (Apr 18, 2006)

holy old thread!!!


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## dlroto (Sep 10, 2006)

Wow my bike is really heavy for it to be aluminum. Thanx for the info, Somehow I need to lighten iut up some.


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