Ninshadow

aluminum is NOOOOOTT stronger than chromoly

FLyBOy

Ok, fine.

FLyBOy

Right, I have already stopped. And there's nothing us 15 year olds need to prove to anyone.

FLyBOy

Cromoly has more flex than aluminum, aluminum is more brittle, but there's some very strong cranks on the market made out of aluminum. I still like cromoly though.

BMXTRIX

Flyboy - Quit while you are behind. You don't need to make individual posts for every single comment - just one post. You can do multiple quotes if you want, but even that you don't need to do. Just say your bit and move on.

A good rule of thumb is that when someone calls you a ***, simply agree and change the subject. It has been established that all bike riders are ****, especially ones who are pompously proud of the city they live in or the websites they run and it doesn't matter if they are married and have kids... they are still ****.

sxe fbm rider

Aluminum is not brittle.. It's not like a rusty cracker or something. The deal is that by definition, steal is stronger than alluminum; but when you're talking about cranks, that really doesent matter. I have profile race cranks, I am a very big guy and have had them for over three years. I broke one cranks arm once, but I sent it back to them and had a new free one in under a week... its garunteed for life, so why get heavier cranks. As long as the cranks are designed well for your purpose it dosent matter steal or aluminum, especially if they're garunteed for life. Differences in flex and all that dont really effect street riding, if thats what your doing, it may play into racing where flex may win you or loose you a race, but not really freestlye riding. Philly, what what.

BMXTRIX

Brittleness of metals is all relative. Compared to to 4130, aluminum has much less flex. As a general rule, any metal with less flex, must absorb any abuse directly into the metal itself. Eventually the metal just snaps. This is typically referred to as how brittle the metal is. So, in comparison to 4130, aluminum is brittle. Aluminum actually has a greater strength to weight ratio than 4130, but the flexibility of 4130 makes it a much better material for street riding. The abuse of coming down hard on a big gap, stairs, or landing gone wrong causes incredible stress on cranks. This is where 4130 really shines because the cranks flex an imperceptible amount to act like a shock absorber. It prolongs the life of the cranks.

Steel also has different flavors that make it stronger, but more brittle, or weaker and less brittle. 4140 for example is stronger than 4130, but it is more brittle which makes it less suitable for frame building, but better for axles and perhaps cranks. Frames, forks, and bars really need a tiny bit of flex to survive the rigors of street use.

I rode a GT Show for a little over a year. It was an aluminum frame and I rode it the same as I had any other frame. In one day, the frame developed a crack. By the end of the day, the frame had developed about a dozen more cranks and broke in a completely different area than where the original crack appeared. When aluminum fails, it fails pretty much completely. I wouldn't trust aluminum on street, even if the cranks will last a year or two, when they break, I probably wouldn't have any warning. Chromoly is much more likely to show cracks and give you at least a little warning.

Besides, Profile cranks kick butt.

FLyBOy

Ok, that has to be one of the dumbest rules I have ever heard of, but I see your point because I don't know if this will ever end. Thank you for the pointer on just dropping it.



That is right, when aluminum decides to take a 'break' you'll be the one who's taking a break for the next three months. And also BMXTRIX, doesn't cromoly bend before it breaks?



Yeah, they definetly do! If my new Redline Monster cranks ever break, I'm going straight to Profile! I mean how can you beat that lifetime warranty?!! Oh by the way, I did finally get my Monster cranks in the mail... and they are as cool as a new car interior!! Nothing like a new crankset huh? No, but really, they look awesome and I think they'll definetly last me awhile.

BMXTRIX

Chromoly doesn't necessarily bend before it breaks. Typically this has to do with areas where 4130 is welded. Welds increase brittleness due to the intense heat/cool down cycle that goes on around the steel at that point. With cranks, it is very unlikely that chromoly cranks will break in the middle of the crank arm. It is much more likely that they will break right at a weld due to brittleness. Cranks not only have welds at both ends, those are also the major stress points for a set of cranks so likelihood of breaking them there increases.

Heat treating and stress relieving can all allieviate brittleness though. Use of 4140 can also help reduce breakage due to increased strength.

FLyBOy

Oh cool, 'cause my cranks are heat treated!

CMcMahon

Aluminum cranks aren't welded; they're made from a solid hunk of metal, which is why they're durable. I've seen plenty of people break and bend Profile Race cranks, but I can't say that I've ever heard of a snapped or bent Primo Powerbite. However, the pedal bosses on aluminum cranks invariable suck; if they have a threaded steel insert, it generally ends up threading out, and if they have threads cut into the crankarm, they often end up stripping or crossthreading.

FLyBOy

So are Profile cranks bad then? I'm just curious because lots of people here have recomended them. Thanks.

CMcMahon

No, they're perfectly fine. Just don't land one-footed out of a roof drop or anything.

FLyBOy

LOL, I don't think I'll ever do that with any crankset, but thanks. LOL

queensrider86

you started this thread asking the question"are chromoly cranks stronger then aluminum?"how would you know that you like chromoly better than aluminum if you never rode either.

FLyBOy

What the hell is wrong with you?!! You get on my back with every post I make! I now know the anwser to my question 'is cromoly stronger than aluminum' , and I never said that I liked cromoly better than aluminum! Were did I say that I liked cromoly better than aluminum?! Huh, where did I say that?!! I said that I still like cromoly, that does not mean that I like it more than aluminum. I don't know if I like cromoly better than aluminum or not, but if I bought any parts I'd prefer they'd be made of cromoly. And what makes you think I havn't ridden either, how would you know! I have cromoly cranks on my bike right now, I just wanted to know wich was stronger! So before you start off again on your little persecution bit, get you facts straight.

Ninshadow

Ok metal is not somthing to argue about. Chromoly is stronger than aluminum. THeir are places where Aluminum is better to use. Likewise for Chromoly. Some people will say they like alum. cranks better. Others crml. What material your cranks are is quite pointless to argue about. If you ride well and your cranks dont bend than you have found your cranks.

bmxrdr88

i've snapped some powerbites.

CMcMahon

Jesus ******** Christ, just stop posting.

pack

i have had both profiles and primo powerbites and they are both strong enough for the masses. Its the design of the cranks that make them strong.
personaly i dont like the profiles because they never stayed tight, once they get lose and you ride home the arms are f**ked, they will never be the same again. the powerbites on the other hand have pinchbolts so there are three bolts holding them tight, its a fit and forget design, never had a problem (my cranks have a steel insert for the pedal thread)



Now that sounds like an insult!
You must have lead a very shelterd life, this is humor. Take it on the chin with a smile, give some back and get over it. LIGHTEN UP

jim-bob

Wow, I can't believe I missed this thread the first time.

Pack, I salute you.

queensrider86

well, nobody has replied to this thread for about 2 months, so now flyboy is calling people names

KinetikBiker

I have PRIMO Hollowbites that havent given me and trouble ive had them since Christmas this year and they are only 1 ounce heavier than the Profile cranks that everyone has....but i have never had trouble with them so far.

KinetikBiker

im not saying that im smarter than you BMXTRIX but i think that the PRIMO cranks are really nice...

FLyBOy

Yeah, I know. Why are all of these peopls repying to a dead thread?! Son-of-a-*****es.....