Modern chainrings are like partly worn out old style chainrings

[ichitan]

With one bicycle I bought, when it was brand new, I could not ride up hill without the chain jumping teeth on the chainring. With other bicycles, the chain has jumped teeth on the chainring on occasions, when trying to accelerate quickly.

I recently replaced the chainring on my bike twice. The first replacement had plastic cranks, which broke when trying to accelerate quickly. I discussed this in another post.

The chainring I am using now, is a new reproduction of a vintage chainring, made for repairing old bikes. The teeth on this are much longer, wider and thicker than the teeth on modern chainrings. The chain never jumps teeth, however much power I apply to the pedals. I will probably never wear this chainring out.

When seeing the difference, I have come to the conclusion, modern chainrings are like old chainrings, partly worn out, so they need to be replaced sooner.

Following is a photograph of a modern chainring, superimposed on a photograph of an old style chainring.

   

[Painkiller]

how do you explain this chainring

[Painkiller]

It is pretty safe to say that your bike or bikes have other issues that are probably caused by improper setup and tuning. I suppose with what you are telling the world about chainrings must also go along with rear cogs too as they are styled much different than much older cassettes and freewheels. You seem to honestly believe that some make components to fail quickly, simply not the case at all. Nobody but you would ever buy "for the second or third time" such components. It is not a good business model. If you are talking about bikes that one can buy a multi-speed bicycle for under $400 US dollars and expect anything less than satisfying you need to realign your thoughts. If you are your own wrench and self taught at that, you should be more open to comments and suggestions from others that do know a tad more than you. It is ok to learn to do things properly. We are our own worst enemy as they say. You make posts and do not respond to questions, which is rude by the way. So just go ahead and keep putting blame on the industry for unfounded accusations and keep on keeping on riding bikes in a state of disrepair until you can get over yourself

[ReapThaWhirlwind]

This is most likely due to being cross-chained. You would have to re-adjust your indexing, or the spacing in your BB (if possible); or the dishing of axle (created by the size and displacement of the spacers and locknuts you're using).

Another common source of this is the b-screw not being tuned properly.

Some cross-chaining can't be helped depending on your setup and the components you have to work with. This is a very common issue for single speed converts using conversion kits. This can cause a clinking sound now and again from the chain being forced back onto the sprocket. If you're using 3/32 chainrings and spockets, then using a wider chain (such as a single speed 1/8" chain) can help in some cases. That design you posted could be (in-part) to help adhesion in this case also. It helps adhere the chain to the chainring—also reducing friction slightly.

Saw a few posts on Reddit recently of similar issues, one was due to their pulley being worn out (maybe their chain too), and another because their derailleur wasn't routed correctly.

[ichitan]

(12-19-2022, 12:34 PM)ReapThaWhirlwind Wrote:  This is most likely due to being cross-chained. You would have to re-adjust your indexing, or the spacing in your BB (if possible); or the dishing of axle (created by the size and displacement of the spacers and locknuts you're using).

Another common source of this is the b-screw not being tuned properly.

Some cross-chaining can't be helped depending on your setup and the components you have to work with. This is a very common issue for single speed converts using conversion kits. This can cause a clinking sound now and again from the chain being forced back onto the sprocket. If you're using 3/32 chainrings and spockets, then using a wider chain (such as a single speed 1/8" chain) can help in some cases. That design you posted could be (in-part) to help adhesion in this case also. It helps adhere the chain to the chainring—also reducing friction slightly.

Saw a few posts on Reddit recently of similar issues, one was due to their pulley being worn out (maybe their chain too), and another because their derailleur wasn't routed correctly.

The reason I have a lot of bike parts fail, is because I am larger than the majority of cyclists.

For example, when riding up a hill, the bike needs to carry more weight, and the pedals need to be pushed harder, which I do because of my weight and strength. A smaller rider could ride the same bike, and not have the chain jump teeth on chainring (until it is more worn).

While I have more bike parts fail than smaller riders, my point is still valid.

If you look at the picture. The new chainring, which is black, needs to wear much less before the chain starts jumping teeth, than the old style chainring, which is a light blue color.

   

In another post, I warned people not to buy plastic cranks. They broke sooner with me, because of the force I put on them. But they flex, and with a smaller rider, they will eventually have a fatigue break. They are designed to fail.

[Painkiller]

I have been building and modifying bicycles for over 30yrs for small, tall, heavy people and light people, handicapped and so on. You simply are not setting up your bike with proper components for your body type. I can assure you with quality components and tuned proper you will not over power and stress the drivetrain so much to be skipping the chain because of your size. I only hope you do not work on other peoples bicycles at this time. Bicycles must be built with a couple things in mind. Industry standards and safety. If you cannot do this for yourself do not do it for anybody else. Never have a bike fail and someone get hurt because of being the mechanic of said bike, if someone gets hurt on a bike you have worked on it should only be due to riders fault or other un foreseen circumstances.

[ReapThaWhirlwind]

Certainly, but innovation usually seeks to perfect upon troubles haunting older styles of engineering.

Not to say components can't be designed to fail. Certainly, I've seen this before in the form of using lesser grade alloys for springs, pivots, etc. They're not only cheaper, but can be critically damaged easier, and wear out faster otherwise.

For example, another scenario in your case;

More material means more contact means more friction.

Those chainrings would be slower when grinding—because they create more friction.

[ichitan]

(12-20-2022, 01:50 PM)ReapThaWhirlwind Wrote:  Certainly, but innovation usually seeks to perfect upon troubles haunting older styles of engineering.

Not to say components can't be designed to fail. Certainly, I've seen this before in the form of using lesser grade alloys for springs, pivots, etc. They're not only cheaper, but can be critically damaged easier, and wear out faster otherwise.

For example, another scenario in your case;

More material means more contact means more friction.

Those chainrings would be slower when grinding—because they create more friction.

If someone was in competition, where anything that makes a tiny difference is important, a little more friction might be of concern, but for casual cyclists, the difference is so small it is not noticeable.

Having the chain jump teeth, is a much bigger problem. I like to know, I can apply as much power as I want, and it will work properly. I also like parts that will last a long time before wearing out.

On rare occasions, it might also be a safety issue. For example, if I need to quickly get out of the way of a truck, I like to know my bike will not fail me.

[ReapThaWhirlwind]

Totally understand. It's unfortunate that wanting more requires more.

You can certainly get them, but they are the higher end components that cost more.

We don't actually have a table of data here, but I would imagine those older chainrings had problems with teeth breaking often. Lessening the adherence friction with the chamfering would also help to reduce this issue. If anything, we could have that (across the board) we have actually chainrings with longer life expectancy now than we used to have—given the reduction of critical failure—with techniques like this applied on them.

If your chain is jumping, there's a good chance it's something else (such as your chainline). You can also recoup this easier by adjusting other schematics on the bike. We can't blame the chainring just yet, or say it holds us back as critically. But when your chainring teeth break—there's no ambiguity to that—and that's truly the end of the ballgame with no recoup.

[ichitan]

Following is a photo of a modern chainring for a pedal bicycle, superimposed on a chainring for a mid drive electric bicycle. The motor combined with peddling, puts out more power than just peddling. If the chainring from the pedal bicycle was used, the chain would jump teeth on the chainring, so a chainring with longer teeth has to be used.