KMC Z51RB Rust-Buster, 6/7/8 Speed, 116L, Multi Color

I'm on my second one of these chains for a Mountain bike that I use for both occasional trails and general transit around college. My bike has to live outdoors, and go through salt / slush / grit, without being regularly washed / cleaned with about 5-10 mi/wk use. I've never had this chain rust. It has either a galvanized or zinc paint coating, which has not worn off / peeled / rusted / etc. The only issue with the coating is that a new chain will wear EXCESS coating away, which produces a black, grease like residue. It's a bit messy, but not as bad as rust would be. It may also be a result of the wet bike chain lube I use.I remember reading a mention of these chains bending under heavy use when I first bought it, I can say I don't think a good example of this chain will do that under normal conditions. In 1+ year of use, I have not experienced any failure personally. I did have a chain fail that way, but it was due to some hoodlums stealing the bike to do BMX. Specifically, it bent over my front chain ring due (I believe) to someone hammering most of their body weight on the front shifter while not pedaling. When it bent, I could have fixed it by sourcing chain pins and replacing the two links affected, from the extra links I got installing the chain, but I chose to replace the whole chain, as I wanted to replace the chain rings and cassette. At that point, (1 year of use) the coating was still sufficient to keep wear surfaces in the chain from rusting after one week of disuse outdoors in the rain, in the presence of salt. Additionally, between the chain lube and coating, it was still quite flexible, indicating internal surfaces did not rust either.

I'm a 4 season e-biker and this is the only chain I've had that didn't rust. In fact, I still have a few links on my current chain that are the only ones still not rusted (I couldn't find these). I'm not sure why e-bike chains aren't sold longer. You gotta have a big chain ring to pretend to be pedaling 30+ mph. The only reason to change these out is because of stretching. I don't lube ever. That just wrecks your chain and gears from collecting gunk. They'll stretch out before you need to do any of that anyway because they're super easy to clean without all the gunk on them. But, these last me a long time without issues. Freewheel and chainring still doing good after a few years and thousands of miles. This is the only chain for me.

This chain is the answer to my longstanding problem with bike maintenance. There are several reasons to lube a drivechain:1. To reduce the friction that bare metal would have2. To quiet everything down3. To prevent wear4. To prevent rustThe problem is that basically any type of lube that prevents rust also accumulates dust/grit and wears the chain, adds noise, and increases friction. As well as getting you dirty. Frankly, it seems to me that after a while pretty much any lube is worse than no lube at all. I've tried a ton of lubes trying to find a solution but there really isn't one. Most recently I was using white lightning "clean ride." It's clean-ish but not CLEAN. It does have some kind of oily residue that accumulates dirt right where you don't want it---in the friction points---and starts making noise.The only really great lube out there is parafin wax. The straight stuff. As in, melt it on the stove and dip your chain in it. It is the best lube at the first three objectives and genuinely does not attract dirt...at all. The only problem is that it does squat for rust protection. I live in central PA and it rains here all the time. This is my every-day commuting bike and is constantly out in the elements. Chains are always rusting out on me. Lubes wash away, mud gets in there. Bad situation.Anyway, this chain has been used and rained on with only parafin wax on it for three months now and doesn't show any rust whatsoever. And because I've been using straight wax it's not getting dirty either. I will never to back to using any "lube" besides pure wax.People say this chain will eventually rust or that the coating comes off. That's not my experience so far. Maybe I'll check back next spring and let you know (I ride all winter long).This is basically the perfect chain for me. The coating isn't as attractive as I'd like...it's not very smooth or machined-looking. On the other hand it's always clean and rust free, just like when I first installed it. So that kind of makes up for it.This chain comes with its own easy-install link. Very nice touch. It's super easy to put on and take off.I will continue to purchase this model from now on. Thanks a lot KMC!============ Edit January 2014 ===========================I guess three months wasn't long enough to evaluate it. After about 6 months, the rust-proof coating on the interior portions of the chain--the parts that rub together--wore through and rusted in the wet and salty winter months. Aesthetically the chain still looks great, but the place it rusted is very problematic. After Christmas break I went riding and several links were rusted enough that they didn't flex easily and the chain kept skipping. I guess my idea of using paraffin wax instead of a lube with rust-proofing capability only worked for so long.So I ended up removing all the wax, cleaning the chain really well, and then lubing it with a very small amount of heavy oil (white lightning wet ride). Since I only care about the internal parts now, I cleaned all the oil off the outside of the chain very thoroughly. All the links move now so the chain is working fine. Hopefully it won't get dirty as quickly as it used do when I coated the outside with oil as well.I took off one star because I now realize this chain is not the ultimate answer. I guess maybe I should think about forking out the money for a stainless chain. In the mean time, when this chain wears out I will get another one just like it. I can deal with lubing the interior surfaces of the chain as long as the outside doesn't rust. It's a compromise but life is full of them.

Perfect for corrosive environments. Clearances are good and performs like regular chain, just doesn't rust. Buy this.

Nice chain for my old 10-speed. It came with a "Missing Link" kind of master link which made installation easy and did not require a chainbreaker tool to do so. So far I have 110 kilometers on the chain and no problems. It looks rust-resistant but I keep my bicycle in the garage and do not generally ride in the rain, so the rust proof aspect is not tested in my use. I am powering a 500-watt motor through the chain and it has held up well to the more-than-normal pedal pressure. Chain is lubricated with some kind of grease/oil, so that will get on your hands during installation, but it is good for,the longevity and functioning of the chain. The chain feels stiff sideways and I am not sure it is good for rear gear clusters that have 6 or more sprockets.

I live in the sub-tropics, the ocean is a 10 mins walk, very humid and lots of rain. My bike is used regularly to commute and its parked outside. Every other brands of chains I've tried rusts and seize in within a month except this one. This is the only chain I buy now.

Totally useable chain.-dude in Boston

I received the Z8.1 not the rust buster. Not a huge deal but slightly disappointing. I’m not going to bother returning it since this is still compatible and the pricing is similar.