Park Tools chain wear tool - changes in newer version?

[horizon]

I have an old(ish) Park Tools chain wear tool. It indicates 1% and .75%. The new tool indicates .75 and .5 and recommends replacing the chain at .5 for 11 speed and .75 for 10 speed. Am I right in thinking that 8 and 9 speed set ups are therefore more economical in this regard (i.e. the chains last longer)? Or is it that 10 and 11 speed chains need replacing sooner in regards to wear but take longer to reach that point?

[keyboardmonkey]

The Park Tool CC-3.2 chain checker? Dunno. I have one and replace all chains at .5 of wear.

Or do you mean this one...?

https://www.parktool.com/product/chain- ... 20Products

[Tiberius]

Or do you mean this one...?

https://www.parktool.com/product/chain- ... 20Products

I've not seen that one before...Sort of the same but different.....

[Sweep]

I became aware of this recently after a debate with someone who dumps his chains at 0.5, but turns out he has more rear cogs than any of my bikes.
My park checker says 0.75 and 1.

All my bikes are 9 speed tops and I change chains at 0.75.

If this is wrong, folks feel free to correct me.

[JonMcD]

Or do you mean this one...?

https://www.parktool.com/product/chain- ... 20Products

I've not seen that one before...Sort of the same but different.....

The new one looks like the old Shimano TL-CN40 & TL-CN41 type where roller wear is eliminated from the measurement because the measurement points are on the same side of the rollers.

[ratherbeintobago]

I have an old(ish) Park Tools chain wear tool. It indicates 1% and .75%. The new tool indicates .75 and .5 and recommends replacing the chain at .5 for 11 speed and .75 for 10 speed. Am I right in thinking that 8 and 9 speed set ups are therefore more economical in this regard (i.e. the chains last longer)? Or is it that 10 and 11 speed chains need replacing sooner in regards to wear but take longer to reach that point?

I think that the issue is that 10sp/11sp are less tolerant of chain wear. I doubt they last longer, especially as with 1x11 its possibly get some slightly alarming chain lines.

LBS verdict on the 8sp XT on the Hybrid of Doom is that it will go on forever; have already successfully killed 10sp SLX on the mountain bike, but in significantly worse mud.

[Samuel D]

The new one looks like the old Shimano TL-CN40 & TL-CN41 type where roller wear is eliminated from the measurement because the measurement points are on the same side of the rollers.

Exactly. Explained here. Nice to see Park Tool offering a tool of this sort.

I don’t see why an 8-speed chain should be replaced any later than an 11-speed chain. The geometry that causes a new chain to skip over a worn sprocket is independent of sprocket or chain width. Perhaps the recommendation is just about 11-speed cassettes being relatively more expensive than chains, nudging the replacement scheme in the direction of preserving sprockets.

Even with an 8-speed set-up I replace the chain when I notice it has hit 0.5% elongation, although I measure with a ruler over about 12 inches of chain. The short indicators that include roller wear usually show 0.5% elongation has been reached before it really has.

[Brucey]

I have an old(ish) Park Tools chain wear tool. It indicates 1% and .75%. The new tool indicates .75 and .5 and recommends replacing the chain at .5 for 11 speed and .75 for 10 speed. Am I right in thinking that 8 and 9 speed set ups are therefore more economical in this regard (i.e. the chains last longer)? Or is it that 10 and 11 speed chains need replacing sooner in regards to wear but take longer to reach that point?

Some park tool chain measurement tools

CC-1


CC-2


CC-3


CC-3.2


CC-4

The instructions for CC2 recommend different readings for different speeds of chain thusly

….The CC-2 is compatible with most derailleur chains. For 9 and 10-speed chains, replace chain at or just before the 0.75% readings. For 11 and 12-speed chain, replace at or just before the 0.5% reading. Check with manufacturer for specific replacement instructions....

but the CC2 is an older design which also includes roller wear in the measurement. CC3.2 instructions say the same thing and this tool also includes roller wear in the measurement. Dunno about CC-3 which is the one that Horizon has I suppose.

The CC4 is the newer tool and the pdf instructions
https://www.parktool.com/assets/doc/product/CC-4_instructions.pdf
don't mention variable elongation vs replacement in the same way. But the CC4 is a better design which measures pin wear only.

I suspect that the CC2/CC3.2 instructions are worded thusly with the idea that narrower rollers wear faster (on the inside) and mess the reading up on that chain tool faster than happens with chains that use wider rollers. Or maybe thinner sprockets wear faster (to the point at which a new chain might skip) too. But this doesn't quite hold water because both 10s and 11s chains/sprockets are virtually identical....

cheers

[Brucey]

It is also worth noting that, from the rider's perspective the objective is usually to change the chain before the sprockets get so worn that they won't take a new chain without skipping.

However this isn't ever a fixed point; it varies with the chain type, the rider, and the pattern of use. So some folk get away with changing the chain at (a real, pin-wear only ) elongation of 0.75%, others can't go more than 0.5% safely.

IME the former is likely if
- the rider is a spinner not a masher
- the rider doesn't ride out of the saddle
- all the gears are used (rather than some seeing the bulk of the use)

However the system is less likely to go past 0.5% wear and still accept a new chain if
- the rider is a masher not a spinner
- the rider rides out of the saddle much
- the peak torque/chain tension exerted is high not low
- some sprockets are favoured at the expense of others
- the favoured sprockets are small not large in size

The chain can make a difference too; I think that roller wear is bad (e.g. because it interferes with the measurement on some chain tools) but it might have a good side too; I suspect that loose rollers are more likely to smack into the back of the sprocket teeth (as the chain engages) in such a way as the tooth wears in less of a hooked shape. This would make a worn sprocket more likely to accept a new chain without skipping.

So I happen to be interested in an exact number for chain wear, but it arguably isn't so relevant for any given rider; whether the measurement includes roller wear or not doesn't really matter, because the exact chain wear won't tell them if they can fit a new chain or not anyway. The point which you have definitely left it too late depend on many things, not just the exact pin wear in the chain.

Most riders will be able to change the chain at a (real) wear of 0.5% but I have seen some where they can do so at nearly 1% wear, without skipping.

cheers

[Sweep]

Thanks for that Brucey.

I think I slip into your rider profile where I can safely change at the 0.75 on my park tool, or maybe push to 0.8, which is the only marker my KMC tool has.

Most riders will be able to change the chain at a (real) wear of 0.5% but I have seen some where they can do so at nearly 1% wear, without skipping.

cheers

But if you left it to 1% would you be endangering the front rings?

One/several other question/s - when you use these checkers, I sometimes get the tool dropping into the chain gaps at only one place (or rather two) on the chain, rather than at several places along the chain. ie - for most tests on the chain it won't drop in. Have sometimes wondered about this. Suggests uneven wear? Fair to assume that even if you just get the wear measured to your chosen wear ratio at a single insertion point you should nevertheless change the chain?

[kwackers]

The CC4 says 5-12 speed, what's a good checker for hg's (1/8 chain)?

[Brucey]

But if you left it to 1% would you be endangering the front rings?....

if the conditions are such that the sprockets are not wearing badly with a 1% elongated chain, the chainrings (with standard road gearing) are not so likely to be suffering either. But if you use smaller, softer chainrings, then they can wear quickly regardless.

One/several other question/s - when you use these checkers, I sometimes get the tool dropping into the chain gaps at only one place (or rather two) on the chain, rather than at several places along the chain. ie - for most tests on the chain it won't drop in. Have sometimes wondered about this. Suggests uneven wear? Fair to assume that even if you just get the wear measured to your chosen wear ratio at a single insertion point you should nevertheless change the chain?

Perfectly uniform wear (to the nth degree) is not that likely, but if the chain is wearing unevenly to a noticeable extent, this may be a clue that it isn't just ordinary wear that is the culprit; it may mean that the chain is corroding as well.

The other thing to bear in mind is that whilst the chain is on the bike, just used, the rollers have been pushed fully forwards and backwards by the chain tension during pedalling. This ought to mean that when the chain is being measured, they move freely until there is metal to metal contact. However there is always some dirt in the chain and if this is disturbed then it may interfere with the measurement by restricting the movement of the rollers.

Thus there are two good opportunities for measuring the chain; when the chain is on the bike (just used), or when the chain has just been cleaned. Since cleaning worn out chains is a waste of time, I prefer to measure on the bike. If the chain shows badly worn in just one or two places that is enough.

The CC4 says 5-12 speed, what's a good checker for hg's (1/8 chain)?

If you are going to change at similar %age intervals then the CC-4 will work on IGH chains too. But IME it is not uncommon for IGH chains to be run well past 1%, in which case a conventional chain checker is not going to tell you anything particularly useful. I would (and do) use a 12" rule or a set of modified Vernier calipers. On a utility bike (with a steel chainring) you are usually just in for a period of rough running (from the chainring) with a new chain if you let the old chain go too far. Sprockets are usually cheap enough that they hardly factor in the calculations.

cheers

[andrew_s]

The new tool indicates .75 and .5 and recommends replacing the chain at .5 for 11 speed and .75 for 10 speed. Am I right in thinking that 8 and 9 speed set ups are therefore more economical in this regard (i.e. the chains last longer)? Or is it that 10 and 11 speed chains need replacing sooner in regards to wear but take longer to reach that point?

I'd hazard a guess that the reason for the different replacement recommendations is economic.

Basically, the lower the wear at which you change chains, the longer your cassette lasts, but you are also spending more on chains.
There will be a stage where the cost of replacement chains outweighs the saving from the cassettes lasting longer, which will vary depending on the relative prices of chains and cassettes. 11s gear costs more than 10s, so it's likely that it is beneficial to change earlier.

[horizon]

I think there was a thread recently where someone said that the cost of an 8 or 9 speed cassette was roughly the same as a new chain so you might as well keep running both until both are worn or slip occurs (or you fear it might).

I'm not sure if there is any significance in the fact that 11 speed is worth protecting due to its high cost as a factor in choosing 11 speed in the first place: it is significant to me but I presume that buyers of 11 speed reckon that it is worth the extra cost of earlier, preventative chain replacement.

https://www.amazon.co.uk/Shimano-HG50-S ... th=1&psc=1

https://www.amazon.co.uk/KMC-Speed-Chai ... lp_pl_dp_3

[Brucey]

If you are only going to neglect a chain anyway, it arguably doesn't make sense to spend a lot of the chain, even if it is one that doesn't last that long even when you do look after it.

For example P-X have both 1/8" and 7/8s chains starting from £3 each. I doubt they are the best quality but I don't think you can get a cassette for that sort of money; running three cheap chains like that to one cassette seems about right....?

In 10/11s the same logic might apply but the cheap chain of choice might be the SRAM PC-1110, which costs about ten quid.

cheers