[Dog Welder]

I've noticed that a number of BMX crank companies produce steal and aluminum versions of their cranks...for example Demolition and Primo to name two companies. Only thing is that these aluminum bmx cranks weigh just as much as a set of steel cranks. Whats the logic behind manufacturing a aluminum crank as heavy as a steel? Do they "ride" different?

 

[scurban]

I don't think so, I've ridden both, and I think Steel is better. I don't understand why the make two models that weigh the same. Some race companies make them in Aluminum and they are a lot lighter. Then its understandable, but in the same weight, I just don't get it either.

 

[dromond]

It's my understanding that the primo powerbites (solid aluminum) or a bit heavier and much more resistant to abrasion (read: grinding) than the also very popular profile race cranks (tubular steel.)

 

[S3C]

- One is cheaper then the other
- Maybe some people prefer Alum over Steel for their own reasons
- Alum doesn't rust, steel does
- Steel is generally stronger

 

[pnj]

some people have problems with the splines on profile type cranks. some people have problems with chromoly cranks. more choices = more happy people.

but I think the real reason is, Primo was able to create a product that kids could use easily and not spend alot of dough doing it. aluminum grinds slower then steel so I don't think that has anything to do w/ it.

personaly, chromo is the only way to go on my bmx bike.

 

[dromond]

some people have problems with the splines on profile type cranks. some people have problems with chromoly cranks. more choices = more happy people.

but I think the real reason is, Primo was able to create a product that kids could use easily and not spend alot of dough doing it. aluminum grinds slower then steel so I don't think that has anything to do w/ it.

personaly, chromo is the only way to go on my bmx bike.

The point is not that the cranks or for grinding on but that they're less likely to get a hole punched in them by a concrete ledge if you botch a grind

 

[pnj]

I've NEVER seen a hole punched in 4130 from missing a grind. in fact, in 20 plus years of riding a bmx bike, I've NEVER seen a hole punched in 4130 period.

seen plenty of broken, snapped, ripped 4130 though.

 

[dromond]

Admittedly neither have I. Then again I don't really see the need for profile SS cranks either.

 

[RandomV]

Well, the Primo Powerbite cranks are basically copies of the old GT cranks that no one would buy years ago. They're stiffer than steel, and in my experience they have been bomb-proof.

My biggest problem with steel cranks are the lack of pinchbolts on the crank arms. I like those. And I hate the "Profile wobble."

As far as the Profile SS cranks, those were kind of a bad idea. The bearings end up being too small, causing easy failure... And they really weren't as durable as you would have probably expected, either.

 

[pnj]

I never had a problem with profiles wobbling. even my heavier friends never had that problem. I have seen profiles bend though. and break, and everything else minus having a hole punched in them.

 

[mcA896]

Well, the Primo Powerbite cranks are basically copies of the old GT cranks that no one would buy years ago. They're stiffer than steel, and in my experience they have been bomb-proof.

My biggest problem with steel cranks are the lack of pinchbolts on the crank arms. I like those. And I hate the "Profile wobble."

As far as the Profile SS cranks, those were kind of a bad idea. The bearings end up being too small, causing easy failure... And they really weren't as durable as you would have probably expected, either.

if your biggest problem with steel cranks is the lack of pinch bolts, take a look in the danscomp catalog/website crank section. theres a sufficient number of pinch-bolt steel cranks in there. azonic 454's are my peronal fav

 

[RandomV]

if your biggest problem with steel cranks is the lack of pinch bolts, take a look in the danscomp catalog/website crank section. theres a sufficient number of pinch-bolt steel cranks in there. azonic 454's are my peronal fav

Well, it's probably not my biggest problem. It's just the one that I think of first.
I've seen six (or is it seven?) sets of Profile cranks fail in the same time that I've been running the same Primo Powerbites, so I'm pretty set in that department.

As far as the Profile wobble, it's usually only a problem for people that don't take care of their bikes. If you just check every once in a while to keep 'em tight, you're usually okay.

Lastly, I'm thinking about trying out the new Primo Hollowbites. They're powerbites, but the arms are hollow.

 

[Weaver]

aluminum cranks can be stiffer... especially if they are beefed up.... like saints versus profiles... saints are much stiffer but practically the same weight...

XTs are very stiff, and much lighter than profiles.... this is coming from a guy that has never ridden anything but profiles... and is switching to XTs....

 

[bmxr]

As far as the Profile wobble, it's usually only a problem for people that don't take care of their bikes.

Exactamundo! Profiles (or any 4130 crank with a 48 spline interface and no pinch bolts) kick ass as far as I'm concerned. Never had a problem and been using them since the 80's. I would never buy a tapered bb interface product (like some of the al arm cranksets). It is a piece of crap design as far as any heavy duty application is concerned. The old octalink XT's were worthless as hell, but I haven't tried the new ones. They look nice...

 

[HTFR]

whats this about alu not grinding as ealy as steel? i don't belive you.

 

[pnj]

whats this about alu not grinding as ealy as steel? i don't belive you.

in theory, aluminum should grind slower due to the fact that it's a softer metal then steel. to test this theory, get some aluminum pegs and go hop on an aluminum handrail. let us know how it works for you.

 

[bikenweed]

I've ridden BMX for almost ten years now, and I might have an answer for ya. Primo has always made all of their parts in Taiwan. Years ago, Taiwan was not capable of producing high quality, tubular 3 piece cranks, so Primo decided to simply beef up a pair of generic aluminum, SQUARE TAPER BB cranks. With extensive marketing, the cranks sold fairly well. I've had quite a few friends ride Primo cranks, and almost all have had problems with them. Problems ranged from threads stripping, pinch bolts not functioning properly, BB's coming loose, arms breaking... the list goes on. Unfortunatly, Primo marketed these cranks very well, so a lot of riders bought into the idea of aluminum cranks that weigh a ton.
Profiles, while not perfect, weigh a little less, and are much less problematic. In fact, I've been riding a pair since 1996, with few problems. And they are "race" cranks, too. The aluminum vs. chromoly debate is pretty much over now. With companies like Truvativ and RaceFace manufacturing ISIS drive cranks meant for abuse, the longevity is about equal to Profiles. However, they weigh less, are easier to work on, but cost substantially more. I still run Profiles today, and will until they break. (EVERYTHNG will break eventually) Taiwan has really learned a lot, and now produces tubular 3 piece chromoly cranks with the best of them. Now the only determining factor is really weight and price.