Steel or Aluminum sprockets-which last longer?

[KruncH]

When it comes to handle bars, 7075 grade aluminum is stronger than carbon steel. I've been told steel sprockets last longer than aluminum. It seems if 7075 aluminum is stronger than it would be less prone to wear. So what's the final answer to which last longer-aluminum or steel?

Thanks for your $.02

 

[cujet]

You can answer your own question by looking at you bike. The countershaft sprocket is always quality steel and often of the hardened variety. I put on way too many miles to be purchsing expensive, short lived aluminum sprockets. I find that the cheap steel rear sprockets last the longest. It may be that the stainless versions last even longer (however I doubt it is worth the price) I pay about 25 to 30 dollars for a steel rear sprocket.

Chris

 

[Jaybird]

Sprocket life is always relative to your chain care.
If you never allow a chain to grow from wear past 1% of it's original length, it will never wear out your sprockets....steel or aluminum.
IF you do let your chain grow past that point, aluminum will obviously wear a bit faster than a harder material.

Folks differ in opinion on this subject, I prefer to use engineering facts when discussing it. ;)

 

[RM_guy]

Originally posted by Jaybird
... I prefer to use engineering facts when discussing it. ;)

Yeah, but what fun is that? :confused:

 

[Jaybird]

LOL...well you do have a point there, RM! :)

 

[jeb]

Originally posted by Jaybird
Sprocket life is always relative to your chain care.
If you never allow a chain to grow from wear past 1% of it's original length, it will never wear out your sprockets

Yes but tossing expensive chains isn't a good option to me, either. Most anyone can get at least a year, and sometimes a lot more, of hard riding out of a good oring chain and steel sprockets with very, very little work. Keep 'em adjusted correctly, clean them when you wash your bike with a soft brush and spray them with a good lube.

 

[los36]

The aluminum handlebars are stonger than steels because they can use thicker tubing while still being lighter than steel. Most aluminum bars are about 4 -5 mm thick. Steels are around 1.5 or 2mm thick. The lighter weight of aluminum allows the use of more material.

A steel sprocket is stronger. There is no way to add material (aluminum) to the teeth of a sprocket like they do on bars.

 

[Jaybird]

jeb,
I know you want to argue about this issue, but I'm here to tell you that you CAN get just as much, if not more, life out of a standard chain with just as hard of riding. It's hard for some folks to fathom, but there are many things that one must be open minded to and not just consider their experiences to be the only way things are.
I am a chain a sprocket man by trade, and I know these things to be absolute facts.
Your maintenance tips are great, but I'm curious...just what do you consider a "good" lube? If you reply with ANY type of a parfin based wax product, then I know what sort of problem you may have had with standard chains in the past. There are only certain types of fluids that are acceptable for chains, be it in the motorcycle industry or in an industrial setting. Many big corporations have had their head screwed on wrong for many years and have spent BIG money replacing things often because of it, when all they needed to to is become enightened on the proper care of their chains and their problems seem to magically disappear. And to their surprise they seemed to find that with proper chain care, they lost the sprocket problems they seemed to have as well.

Just as an example, I had a customer who was replacing a #120 chain (big sucker) every three to four weeks. This particular chain was running 20 hours a week, non-stop. They were caring for it by the book...their book, which was totally wrong. After I enlightened them, and did a little training session with the caretaker of said chain, their next replacement of that very same chain had not occured....three years after my session with them. You figure it out.
I'm not trying to ba a hardass about chains, I just happen to know them and make a good part of my living working with them. Oh yeah, I could keep selling them this chain every month and make good money doing it, (at ~$500 a crack) but I am into helping my customers make their equipment last instead of raping them just becasue they don't have many clues.

los, the strength of sprockets is not a factor if the lighter metal has enough intergity to handle a chain, which in this case, aluminum does.
A stonger sprocket only allows you to run a trashed chain longer. A trashed chain is also dangerous to the rider.

 

[23jayhawk]

My $0.02, directed to the original question:

When we talk about strength, that can be either yield or tensile. Yield is when the material begins deforming past a certain % - basically turns to the right on the stress/strain curve. Tensile is when it fails (shears). We're probably most interested in yield strength for handlebar and chain applications, since once they are bent they have no further use to us.

Yield strength for a 7075 Al treated to a T6 condition is ~ 62,000 psi. A typical low/mid carbon tempered steel, 1040, should get you to the mid - 80's. And a low alloy tempered steel, like 1340, goes over 200,000 psi. It's important to note that the steels gain much of their strength from the quenching & tempering process; without it they're about equal to aluminum.

The main advantage of aluminum is its density - more material for a given weight (or less), to achieve equal strength.

 

[jeb]

I don't WANT to argue about anything. I was merely relaying what I've learned over the years from myself and others about what works in the mud, sand and water where my chains and sprockets live. I use Honda HP lube. I have no idea what's in it but I still maintain that whatever chain lube I use will be ground away quickly in the mud anyway.

I'm not putting down your knowledge or experience. We've been down this road several times before and you never come out with what this magic formula is for chain maintenance even when I asked you to contact me off-board about your lube. I consider myself open minded but there's no information here to change my mind with.

Even if I was to learn your system and it is as good as you say, I'd still run the best xring chain I could get and steel sprockets. They should last for years then, right?

 

[Jaybird]

jeb, Are you going to DW?

The chain on my bike now is a standard chain. Been on the bike since circa Jan 01. Did DW last year and many other mud rides. Last measurement it has grown 1.5% from new and no sign of wear on either sprocket. Chrome-moly front with aluminum rear.
I have no magic, It's just that when folks argue that steel sprockets are the trick, they are dead wrong.

 

[jeb]

No, not going to DW.

You say you have no magic solution but you also talk about how one of your customers got their chains to last many times longer using your advice and/or products. Sounds like you have something to give or sell. Not a put down for trying to sell a better product or method, just an observation.