I have broken one of the rear derailleur jockey wheels. 13 tooth top and 15 tooth bottom. I'd like something better that the plastic OEM wheels. This bike is about 5 years old, and has been sitting since it broke, 2-3 years ago.
Sorry for the fuzzy cell phone pics, but you can still make out the broken plastic wheel.
New wheels or a whole new upgraded rear derailleur? Any recommendations? This bike will be used on old logging roads and well used trails - nothing cross country or off road.
There are aluminum pullies, for after market replacement. I personally have not heard any good reviews from them. But not bad either. Metal pullies will significantly increase your chain wear, and stretching. Your tourney derailleur, is shimmano's mid level, high range derailleur. Not too expensive, but a fairly well performing piece. You should look at some prices and reviews and determine what your best financial interests are. The most important thing about pullies is this....there is a huge difference between top and bottom pullies. Especially in a high gear-range bicycle. The top wheel is specifically designed so the bearings move smoothly, and slightly side to side to help compensate for the off angle chain line. They are not all created equally.
You might have not checked, but the bolts holding the wheels may infact be rivets and not threaded. So theres that too.
You can often get replacement pulleys from your local bike shop for free - or very nearly free if you are willing to take a slightly used one from an old derailleur they have hanging around in their shop. Replacing this part with aluminum would be overkill. Some parts are just going to wear, and you need to be ready to replace them. Chain, cassette, pulleys, chainrings, cables, housing, and brake pads are the major contenders. Keeping your brakes and derailleur adjusted and your cables/housing in working order will reduce the wear, but not eliminate it.
Now would be a good time to evaluate the wear on those other parts I mentioned - if your cassette has worn teeth, they will be sharp and pointed. A worn chain is harder to detect, but the links can feel a little loose, and you will be able to twist it easier than a new chain. If you take it to your local shop, they'll have a tool you can use to measure chain wear. Replacing a whole system at once instead of one piece at a time reduces the wear on the new component. For example, if you have a worn cassette and a new chain, the chain will stretch to try to mesh with the worn cassette.
If you are looking for long-term reliability without having to replace parts all the time, I would suggest looking into converting the bike to a single speed. This eliminates many of the parts that wear quickly, and the chain and gears on single speed bikes are thicker and beefier, so they last a much longer time. You also won't notice the wear as much because there is no shifting to degenerate.
I would think that there are so many old bikes lying around that you could probably find one for free or very cheap that you could salvage another derailleur off of or just ride the "new" to you bike. back when i was all into tricking out my bike (which eventually got stolen) I replaced my pulleys with aluminum and they did fine. I'm really bad about bike maintenance in general and will ride until something breaks. I don't ride everyday either, btw.
I found some pretty shells, some sea glass and this lovely tiny ad: