Squirrelli

I was just looking to purchase a new chainring for a set of cranks I will be using and I was wondering if chainring materials matter or does machining of the chainring matters more?

This chainring will be used on a fixed gear bike so, tooth pattern, pins, ramps, all of them are out of the picture. I just want some general opinions on different grades of aluminium such as 6061, or 7075-T6, do they really make that much of a difference, in terms of longevity of the chainring and the strength of it.

MichaelW

I have used old chainrings as material for projects and cut them up with a hacksaw.
The premium grade material (sometimes called Zircal) is much harder than standard grade. They do last longer but the main cause of wear is using worn chains.

HillRider

Even cheap chainrings last a long time if the chain is kept reasonably clean and not allowed to wear excessively. I wouldn't agonize over minor differences in alloy.

Charles Ramsey

I had a 20 tooth stainless cog made by sugino it never showed any signs of wear or deformation. Chainrings without the ramps and pins will last twice as long and they are cheaper.

JohnDThompson 

A SS/FG drivetrain is much more tolerant of worn teeth than a multi-gear drivetrain. Most quality rings these days use 7xxx series aluminum. The higher price of true "track" rings reflects closer machining tolerances ("rounder" than road rings), but if your crank arms are not similarly precise you may not appreciate any advantage to the added cost.

onbike 1939

I remember the editor (Frank Berto?) of a well-known American Bike magazine did a series of tests involving the durability and hardness of the materials used in making chain-sets way back. He found that Campag used the hardest grade of aluminium at that time.

HillRider

I remember the book he wrote sometime in the mid to late 80's also. IIRC, his tests showed Campy and Shimano made the hardest chainrings and TA the softest.

noglider 

Sometimes, I think we'd be better off if we went back to steel chainrings. Replacing chainrings is annoyingly expensive.

HillRider

I get 30,000 miles and more on a set of Shimano chainrings so it's not as if they are being replaced every six months. Then too, do steel rings actually last that much longer?

Squirrelli

Thanks for the information guys! I think I will be okay with a slightly lower grade aluminium such as 6061 as long as I put a new chain on and keep it nice.

brokencase

If you want a chainring that will last then go with stainless steel. The weight difference is minor and the cost is only a little higher. If it was a road bike then your choices would be different, but since this is a fixed gear I think you should go with stainless.

tcarl

I think keeping the chain clean is important in chainring longevity. I have a 30 year old Campy Nuovo Record chainring I recently inspected closely to see how worn the teeth were - I couldn't detect any sign of wear. I have and still use Suguino AT triples and find their chainrings seem to be a softer metal and do wear, but I get many years out of them anyway. I keep my chains clean, dry (maybe too dry, but they don't squeak), and not sloppy. With a fixed gear you won't have any chainline issues either. I'd recommend lubricating the chain properly, and then periodically wiping it off with a rag to keep it clean, buy a decent quality chainring, and it should last a long time.

noglider 

30,000 miles is a long way, for sure. I guess this isn't one of those "sometimes" when I think steel would be better. I don't have any data, but I would guess that a steel chainring lasts longer than 30,000 miles. Not that you necessarily need it to.

fietsbob

I bought a Surly (QBP) stainless steel chainring , they are made for single speed cranks ,
Mine is on my Rohloff Bike. they're made in many bolt circles and tooth counts,
up to 50t.

My old touring bike has regular steel chainrings , from the 80's pre index ,
so also a full tooth type.

MnHPVA Guy

My main business is shortening cranks, by drilling and tapping new pedal holes. Most cranks are 6xxx series alloy, no sweat. On the rare occasion that someone wants me to shorten a 7xxx series crank I charge almost twice as much. I have to use a new tap, cheater bars on the tap handles and add extra bracing to ensure that the force needed to turn the taps doesn't move the crank in the fixture.

AFAIK I've never used 6061 rings. But I have used harder 2024 rings and they don't wear nearly as well as 7075s. For a single front ring you can't go wrong with either Salsa 7075s or Surly SS.

noglider 

Interesting! Mind if I ask you questions about that? If so, I would start a separate thread for it.

DOS

So here's something about Shimano chainrings that I am wondering. My bikes have generally had either ulegra rings or whatever rings came with my Truvativ cranks. My wife has 105 cranks/rings. When cleaning rings, I often noticed that the dirt was harder to get off my wife's rings -- usually needed at least water to get em clean whereas I could wipe most dirt off my rings with a dry rag. Recently I needed to replace one of my truvativ rings and found a cheap 105 53t ring, so I used that. Same deal, takes a bit effort to get dirt off the 105 rings as compared to the ultegra and truvative rings I use/used. So what explains my experience. Are 105 rings coated or not coated with something that makes em stickier? If it matters, 105 rings are a different color (light silver) than Ultegra 6500 rings (more of a flat gray).

HillRider

I assume the 105 rings have a more textured surface, maybe bead blasted instead of polished, that tends to hold dirt more firmly. There is no way the choice of alloy could cause that problem.

AEO

105 rings are stamped and they do have a texture.

ultegra and DA are forged

DOS

Ah; I wasn't thinking the alloy would be the issue. More wondering if the color difference implied the surface of Ultegra had been coated with something (analogous to teflon nonstick pan) whereas 105 had not. But textured surface perhaps is the explanation.

conspiratemus1

Mike Barry (Canada's "Mr. Bicycle" and father of TdF racer Michael Barry) says steel chainrings wore faster in his experience racing in the 1950s-60s than aluminum ones. He doesn't know why this should be but says on his blog that he suspects the aluminum makes an early accommodation to the precise shaping of the chain rollers and then stops wearing. Steel always puts up a fight and therefore keeps wearing away. Voice of experience, fwiw.

Replacing worn chains is certainly important. If the pitch of the chain elongates it's going to present an ever-changing wearing force against the teeth of the rings.

noglider 

Hmm, interesting. Again, that applies to derailleur bikes. Bikes with single chainwheels and single sprockets don't seem to have problems, for various reasons.

I got a bike with the most worn chainrings I've ever seen. Of course, it was abused in many other ways, too.

brokencase

Sorry, but I disagree with the legend. Aluminum chainrings will wear faster than stainless steel. This is just the way it is. In addition, harder components all around will exhibit less friction and will last longer. This is why ball bearings/races are super hardened and rifle barrels get chrome plated. Aluminum chainrings are sometimes anodized (like shimano does) and this does create a hard surface, but it is thin coating and eventually it wears through. Once you see shinny aluminum in the valleys of the chain teeth, serious wear begins.

electrik

No, not really... Most chainrings are made in a way last a long time unless you grind them down on rocks. You might be splitting hairs.. steel will be heavier but might last longer, aluminum is lighter, won't get rusty and will probably give you decent mileage... either way the force on each tooth is a lot lower on cranks vs cassettes... which is why one can be made from aluminum to save weight.

LesterOfPuppets

Quite a few MTB little rings are stainless steel. I wish more stock middle rings were also.