Campagnolo's 0.3% 'wear' limit on 11S chains

rjkflyer

Sorry that this is a longish post, but hopefully some of you may find it interesting...

Am thoroughly irritated by the 0.3% wear measurement Campagnolo talk about, BECAUSE their prescribed method included roller wear that we know is largely irrelevant.

Just measured mine in the 'usual' manner and 750 miles in , and I get 132.45mm versus a 'new' of 132.20. This is 0.283% which is close to Campagnolo's 0.3% limit. This means that a 50-year old, light, non-pro duffer is achieving Olympic wear rates of 1,000 miles a chain. Unlikely.

This ties with the fact that when I removed my Chorus chain (which was 0.3% 'worn' by the usual method), I couldn't see any perceptible difference in length when I hung them both up. Not that i looked terribly carefully to be fair as I was swapping for a Record chain.

So, have tried a method to measure which I believe is more accurate, facilitated by the Record chain has hollow pins. Hey presto – a way to measure the actual pure elongation and REMOVE roller wear.

1. Took two hardened taper pins I have from my clock spares box
2. Found two with exactly the same maximum diameter (1.9mm)
3. Inserted them 10 links apart into chain (pushed well in)
4. Stood on pedal to tension chain with rear wheel on ground
5. Measured the distance between pins with vernier – outside to outside
6. Came to 128.99mm
7. Subtract two half pin diameters (= 1.9mm)
8. So actual chain link spacing over 10 links is 128.99 – 1.900 = 127.09mm
9. Therefore actual elongation = actual less theoretical distance
10. Theoretical distance over 10 links = 10 * 25.4 * 0.5" = 127mm
11. So, elongation equals 127.09 - 127.00 = 0.09mm (3.6 thou)
12. Over 10 links, this implies pin wear is 0.009mm (just under half a thou) per pin right now
13. Percentage elongation equals 0.09/127.00 = 0.07%

All this means that I should REALLY be getting about 4,000 miles per chain before it is actually 0.3% elongated.

This appears more reasonable, but it leaves the huge unknown: do Campagnolo MEAN 0.3% elongation measured PROPERLY?

If it's by 'their' method in their instruction books the chain will be barely worn...

Thoughts?

ugo.santalucia

They set unrealistic targets to sell more spares and protect themselves... Imagine you complain because the super narrow chain broke on a climb leaving you with severe road rash... there they show you your chain was 0.3% worn, hence needed replacement. It's like that for everything... in their books you should spend 500 pounds every six months in spare parts to keep your bike running smooth

pinno

Testicula tacta omnia pericula fugant - comes up in a Google search, yer famous.

ugo.santalucia

pinarello001 wrote:

Testicula tacta omnia pericula fugant - comes up in a Google search, yer famous.

Somebody must have said it 2000 years before me...

cycleclinic

If roller to roller measurement is to be used then ideally the rollers should be pushed tin the same direction campag chain measurement technique does not do that so it is not ideal but I am not clear if your method pushes the rollers in the same direction on not.

Campagnolo's recomendation does give a short chain life which is why I ignore it but if you want to run a chain rotation system and have four chains are put the new one on when the old one reaches the wear limted and after the fourth chain go back to the first worn one then campag's wear limt has it uses.

Also I have never managed 4000 miles out of a chain. I generally get 1000-1500 miles out of the chain on my own bikes and if I leave much loger the cassette is toast. Sometimes I find after 1500 miles on of the cassette one sprocket is too worn to reuse the cassette. So while camapgnolo chain wear limits may be over cautious there is no need to sound so religous about it all. 4000 miles on one chain will wear the cassette out and skipping will occur before that mileage wel it does for me. If you have a chorus or record cassette it will be worth running a chain rotation system or at the very least changing your chain sooner to preserve you expensive cassette for longer.

keef66

" but I am not clear if your method pushes the rollers in the same direction on not"

From his description it is clear that the rollers do not feature at all in the measurement. He's effectively measuring between the centres of two hollow pins. Very clever!

rjkflyer

keef66 wrote:

" but I am not clear if your method pushes the rollers in the same direction on not"

From his description it is clear that the rollers do not feature at all in the measurement. He's effectively measuring between the centres of two hollow pins. Very clever!

Precisely, thank you.

keef66

RJKflyer wrote:

keef66 wrote:

" but I am not clear if your method pushes the rollers in the same direction on not"

From his description it is clear that the rollers do not feature at all in the measurement. He's effectively measuring between the centres of two hollow pins. Very clever!

Precisely, thank you.

Quick, delete these posts and file a patent application!

cycleclinic

I use a vernier caliper to mesure elongation roughly and will only do that is the chain checker show more than 0.75% elongation. As the chain checker shows roller wear so 0.75% wear on that is more 0.5% hense the vernier comes out at this point. I tend now to change the chain after 1000 miles or 0.5% wear and keep that chain and throw a new one on. Run for another 1000 miles and repeat. After 4 chains I put the first chain back on and the hope is that the cassette will last a very long time. It is a hope I will see over the next year or so. I am doing this on my dura ace cassette at the moment as I really do not to have to replace it so some time.

The OP chain measurement technicque is clever but is does require 1.9mm pins. Not many people have those, I don't.

rjkflyer

thecycleclinic wrote:

The OP chain measurement technicque is clever but is does require 1.9mm pins. Not many people have those, I don't.

Sorry, should have been clearer - I simply took a box of taper pins I have for clock repairing and took one that fitted the chain hollow pin. It happened to be 1.9mm at the widest end so I found another that was the same diameter simply for 'tidiness'.

(Why taper pins - so that I could be sure that they always fully engaged and centrally in the chain hollow pins, but with slightly less accuracy you could just use small panel pins that were a snug fit. Best file ends off them as these tend to be less regular in shape then the drawn bit of the pin).

In fact provided you measure the two pins you use, they can be ANY diameter, and dissimilar, provided you just know EXACTLY what each is.

So, if you happened across one 1.7mm and one 2.1mm, you would do the vernier measurement across the two and then subtract 0.5 * (1.7 + 2.1) mm.