Chain length

[Blue Hills]

Which ones?

the extreme ones.But the chain shouldn't touch itself at all.

 

[rusty bearing]

Whilst it might have worked for you 'every time' this is not advice which I recommend others follow. It takes no account of how large the large sprocket and large(st) chain ring are so may result in either failure, difficulty or damage to change into the largest sprockets when (doing so by accident eg in the dark) in the large chain ring.
Large to large, not through rear derailleur and add one link (one inch), and if 'in between', go up.

Perhaps not but using the large large and add is logically 'the chain can't be shorter'. Mine is just the opposite approach in that the chain can't be any longer either or it will be too slack and rub on the mech or just plain hang down . There's definitely some extremes out there ,thinking 10-44 which push the limits

 

[EasyPeez]

[QUOTE 5131222, member: 9609"]You're quite right it is a silly word to use, but no more silly than needing to stretch the money in my pocket out a bit further. Elongated would be better.

The wear between the rollers and the sprockets is quite secondary though. The initial wear is between the Pin and the Inner Plate, when this wears the pitch becomes greater and the teeth on the sprockets suffer.

Here is the pin from the link I removed from a chain at 2.35% wear - you can clearly see the wear created by the inner plates.. The other side of the pin is completely unworn - if you really wished to make the most of your chain you could completely dissemble it, spin the pins round by 180 degrees then join it all back together- you would certainly get a few more miles. Of course the inner plates will also be worn so you probably won't double your mileage - but it would certainly be the environmentally friendly thing to do.

View attachment 393539

i measured that as 3.61 & 3.48mm that sort of suggests 3.6% so there is some discrepancy with my measurements somewher ?[/QUOTE]

Thanks for that explanation. It wasn't my intention to be pernickety about your terminology - I didn't realise that there are effectively two types of wear at work, so I couldn't understand why your chain (or any chain) would actually lengthen by 8mm. I thought you must have come across the phrase 'chain stretch' and imagined that your chain was getting longer as wear increased.

But it seems that the wearing of rollers wear between pins and inner plates actually does elongate a chain? I never knew that; makes sense now why it's called chain stretch, even if there is no actually stretching going on.

Cheers.

 

[Ajax Bay]

Perhaps not but using the large large and add is logically 'the chain can't be shorter'. Mine is just the opposite approach in that the chain can't be any longer either or it will be too slack and rub on the mech or just plain hang down .

The difference is, your method (merely) mitigates the risk of a bit of rubbing with the cage/RD fully 'folded' and you'll hear the RD/chain 'complaining' as soon as it does this - and you can immediately do something about it (shift onto the large chain ring). What it fails to address is the inadvertent effort, when in the large chain ring, to shift up to the larger/est sprockets, with potentially damaging (and ride ending) consequences.
By experiment my RD-5700 SGS (I think) can manage to 'wrap' 37 (my normal 52-42-30 and 12-27 setup) but not 42 (52-42-28 and 12-30 - for hilly long rides eg Mille Pennines). For the latter I accept a bit of chain rub (which I can hear) if I'm carelessly in small-small so that, in the dark, inadvertent large-large will work.
Do riders really run a 10-44 with two chainrings? - seems esoteric.

 

[slowmotion]

without - see http://sheldonbrown.com/derailer-adjustment.html#chain

http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html is one calculator but you need to measure the chainstays to use it.

I use the machine head one. You can get the chain stay length from your bike manufacturers website if you delve into the manufacturer's online technical documents.

 

[rusty bearing]

Do riders really run a 10-44 with two chainrings? - seems esoteric.

Yep, on mtb's.

 

[Ajax Bay]

This disparity might come from different approaches to counting links. What is a link? Since the only way to reduce a chain is to remove a rivet, it might be best to consider a "link" as the unit which can be varied. (Leaving out the quick link, obviously.) I put a new chain on my old 10-speed yesterday. 52 links - on my suggested method of counting.

Good luck with that. No chain maker marks their boxes that way AFAIK.

Think you're right but that doesn't make it 'right'.

The pieces of a chain
"A bicycle chain is made up of lots of individual pieces. These are the pin, outer plates, inner plates, bushing and roller. On most modern chains, the bushing is integrated with the inner plate and holds in the circular roller.

"Each chain link is joined onto the next, alternating between outer plate and inner plate. A whole chain link is commonly thought as one segment of outer and inner plate together."

 

[mjr]

A bikeradar article containing an error - whatever next!

 

[Apollonius]

I can't see that it matters. I just find it easier to count to 52.