Inconsistent Chain Wear Measurements - Replace now or not?
 

My main ride is the Novara. While preparing to clean and lube the chain, I measured it using the Park gauge (I now realize that many here don't think it's very accurate). While measuring, I found that the 0.50 indicator dropped in completely at some links, but completely stayed out at other points on the chain. At no point did the 0.75 gauge fit in. I'm at about 2,500 miles on this chain.

Is it common for chains to measure inconsistently like this? Should I replacement it now, or put a couple more hundred miles on it? Cleaning has been every 100 to 200 miles with a Park Cyclone, citrus cleaner, rinsed several times, and then dried thoroughly. The chain, a SRAM PC 850, has no surface rust. Most rides have been on blacktop, with occasional limestone trail rides.

I would measure with a ruler, and continue to ride.

Seems unusual to have readings with the chain checker vary so much.

You may be wearing out the chain prematurely from excessive cleaning.

Sounds like you're doing far more maintenance/cleaning then most do. That's good. That's why when many will have a nearly worn out chain (2500 miles) yours is still in good shape. But chains are cheap so if you want peace of mind replace it when you get too wrapped up in indecision. One aspect of chain wear few talk about and there are no measurements to be made for is the chain's lateral flex. This effects shifting, especially on the front. I've seen chains measure as not much worn but have significant side flex and a replacement sharpens up the shifting a bit. Andy

What??? Andy

Stripping all the lubricant out every 1-200 miles.

With a water-based cleaner, no less.

I re-lube my PC-850s with Chain-L every 500-1000 miles, and they're currently knocking on 5000 miles each without reaching the 1/16" wear point.

I've used a rare earth magnet to attract steel wear particles flushed out of chains that had only been ridden 200-300 miles using mineral spirits, and the metallic sludge that was attracted to the magnet completely coated the magnet with a shockingly thick layer. I consider stripping out all the lubricant (and the gunk and wear debris it contains) from a chain to be a good thing, so long as one relubes afterwards.

And by doing so also removing the grit and abrasives then adding fresh and clean lube. If you go by your concerns it would be bad to change your car oil and filter every 1000 miles. (And I not suggesting that one does that, just that the engine would be used with less dirt in it).

I'll add that as long as the solvent is properly dried and no corrosion occurs then except for the amount of time and effort there is no elemental reason why doing what the OP does is bad. While the frequency might boarder on the OCD side of the usual I see no issues with it. Andy

Not all that unusual to have uneven, measured wear. The chain needs to be pulled tight when you measure so make sure you check it this way. Measure with a ruler before replacing your chain and note if the measurement you get is similar to the chain tool. I find most chain checkers end up being overly pessimistic.

I use quick links on my chains and find that chain wear gauges tend to show more wear if the gauge straddles the link.

If it starts to slip or looks like garbage then replace it. Chain measurements are kind of silly if you are not a racer.

Flushing a car engine with citrus degreaser and rinsing with water every thousand miles would not be a good thing, IMO.

The OP doesn't detail how thoroughly rinsed, how thoroughly dried after rinsing, how thoroughly and with what the chain is lubed.

I'm not a capillary action doubter, but can still imagine solvent & water remaining in the chain, preventing full lube, and those chain cleaners don't necessarily do much inside the chain where it matters.



Agree with SethAZ that cleaning after the initial wear-in period is good.

I let a chain go too long last year, and had to replace chain, cassette, AND chainrings.

With that background, if the Park chain checker is showing that kind of uneven wear, I'd replace it. $15 for a chain? Lot cheaper than what stupid me paid.

Toss the chain checker and measure with a ruler.

Again, this is obviously incorrect. You can use a chain w/o slipping to the point that it has negatively impacted the cassette. Replace the chain at the proper interval and the cassette will last through several chains. Wait until it skips and you will replace both chain and cassette each time.

Chain wear is a complex issue. Some chains wear by elongation that can be measured with a precision rule and others like Campy chains do not. Some chain wear gauges add roller wear to elongation and give exaggerated results. Campy recommends measuring between the outer plates to a length of 132.6mm before changing chains. That measurement is a mixed bag of elongation and roller wear.

The idea that new lube, applied after chain cleaning won't penetrate properly is nonsense, but if a water based cleaner is used, the water must be removed before lubricating. I use naptha/white gas/camp stove fuel and allow a full day for the solvent to evaporate, but my wax lube uses the same solvent to dissolve the wax. I use several chains in a rotation and usually switch to a fresh chain about every 500 miles.

Well, if you are not a racer or also not a person who wants to replace chainrings and cassettes more often.

I first learned about chain wear by riding a mountain bike until the chain was so worn that it eventually just snapped. I'm sure there were signs of things not working as well as they should have long before then that I just didn't have the experience to recognize. By the time the chain snapped the cassette cogs that were used a lot, and the large chainring were so badly shark-toothed and worn that I ended up having to replace them too. I'm firmly in the camp that measuring chain wear and discarding a chain that has crossed some threshold is a good idea.

At some point one has to trust that when someone says stuff, like " rinsed several times, and then dried thoroughly. The chain, a SRAM PC 850, has no surface rust " they are not fibbing. I guess that instead of doubting the OP's technique and it's description I chose to believe them. Others might wish to see wiggle room. Since I have no dog in this fight I'll move on. Andy

Why?
If the chain checker shows good, a ruler isn't going to make it look bad.
If the chain checker shows bad, THEN measure with the ruler to verify.
The .5% mark on my CC is really .25%. As long s I know what it is, it's a quick tool that tends to keep my hands much cleaner.
IF I use a ruler/tape, I measure a 3' section and reduce my error from parallax etc. to 1/3. I don't know why people seem to insist on measuring just 12"?

I don't doubt that the OP is doing what he's doing, but noticing that the chain is pretty worn for the mileage,

so the method may not be the best.

I'll move on as well. Cheers, Jay

I believe I wore out a chain, and cassette from cleaning to often. After I retired I started riding, which consisted 95% riding on crushed limestone trails. I bought my bike at the end of last May, and put 700 miles on it through the summer. I was cleaning and lubing my chain sometimes after every ride. At least every other ride. the limestone dust would coat my chain after every ride. I cleaned the chain with the Park chain cleaning tool, and de greaser, then with dawn dish soap and water, then rinse. Then I would apply a wet lube after the chain would dry. . At the end of last fall I decided to check my chain for any wear not expecting to find any. What I found was a worn out chain, which I replaced with a new one, which ended up slipping on the cassette. I then replaced the worn cassette. So a worn out chain and cassette in 700 miles. I believe with the wet lube, and limestone dust sticking to the chain, it created a grinding paste. Since I have gone to using paraffin wax which collects very little dirt. I ride with others that use a wet lube, but their chains don't wear out like mine did. So the constant cleaning must have had something to do with the chain wear. Maybe i didn't get the chain dry enough either after cleaning. Don't know, but I do know I'll never go back to a wet lube for the kind of riding I do.

Until I joined BF I didn't know bikes chains even wore out. My old (1987) cheap mountain bike had 8,000 miles on it. I never changed the chain and seldom oiled it.and the drive train worked perfectly when I gave it away.

My new (2018) bike went into the shop for some repairs with only 1,000 km on it and the service person said the chain was stretched. Since it didn't cost much I had him change it even though I was suspicious about his assessment. Now I just measure it with a tape measure. If I get 12 1/16" (.5%) between I believe 24 links I might change it. I measured the replacement chain 1,000 km later and it measures exactly 12", as I expected.

I'm not fanatical about keeping my chain clean. I wipe it down with a paper towel and short bristle brush about every 200 - 300 km and re lube it with WD40 "Wet Bike Chain Lube".

Edit:

That 8,000 miles on my chain may have been on 2 bikes. I may have just moved the odometer from my old 10 speed. This would sound more reasonable. I weighed about 150 lbs and didn't do much tough riding on the mountain bike.

2500 miles on a cheap 8 speed chain? Imo, get a new one and stop worrying about making it last forever.

Even if its not elongated to 0.5% the rollers might still be worn. Some chain gauges includes the roller wear, some not. That may be the reason the shop recommends replacing the chain, even if you ruler says no. Imo its debatable if roller wear should be included, but from my experience a chain that is not yet elongated to 0.5%, but has a lot of miles on it, tend to ride notably less smooth than a new one.

Good point, I never thought of that. I did have some trouble with the chain not fully engaging the gears when I got the bike. I may have turned the adjuster on the shifter and messed it up. I may have damaged the chain trying to get it to engage. I recently tried to adjust the front and rear derailleur's so now this Shimano Altus triple chain ring is shifting OK if I'm careful, and the rear is not jumping between gears any more.