Chain life?

[yashicamat]

Would I be right in thinking the constantly perfect chainline on a singlespeed or fixie contributes to a much extended chain life?

The reason I ask is the other day I thought my SS needed a bit of TLC having had close to 1000 miles on the road without being touched (bar two punctures and the odd dash of wet lube), so I cleaned the chain and two cogs up and while at it, measured the chain (that I had actually aquired from a colleague and had already had some use, although I have no idea how much). The wear was virtually non existant! Now the SS goes out in crappy weather all the time (one of the main reasons I built it so I could keep my 'nice' bikes out of the salty winter commutes) and is always going through gritty puddles etc, but it would seem that the chain wear is extremely slow . . . unless I've got some sort of magic chain on the bike (eBay anyone . . . "chain that never wears out"). Most of my chains on various bikes show some degree of wear after 1000 miles, even the touring bike which has very extensive mudguards so the rubbish on the chain is limited.

What do people think? I'm quite chuffed really as the SS was budget cycling as it is, but if it makes bits last even longer then that's a double bonus.

 

[fossyant]

I tend to change every 6 months or 2000 miles, although this time the chain was on for about 10 months - 4000 miles as I was changing the whole drive system.

Usually it's:-

Chain 6 months
Sprocket 12 months
Chainring 24 months.

Sure this is a bit often !

 

[Gerry Attrick]

I think deralleurs in general can be quite tough on chains. The constant forcing from one sprocket to another must take its toll and of course habitually running out of line.

I think that's why chains also last longer on recumbents as the alignment angles are much shallower.

 

[McrJ64]

I find chain stretch is a big problem. I have to change it about every 2500 miles, which is more frequently than I changed it when I was using a derailleur. I use a single speed freewheel more than fixed though (freewheel for commuting, fixed for club rides). Maybe the freewheel is hard on the chain - a derailleur is sprung and might be easier, a fixed applied pretty constant pressure. Does that make sense? I might try fixed for commuting too though, listening to what you are saying about saving chain wear.

 

[totallyfixed]

Well, I've done over 20,000 miles on my fixed and I change the chain every 2 months or so which usually equates to about 900 miles but often a lot more in summer months. The reason I do this [I'm using 3/32] is that if I leave it longer then put a new chain on it tends to be a bit noisy due to the rear cog having worn a bit.
Fixed wheel wears out a chain in my experience faster than gears or ss freewheel, there is a lot of torque going through the chain on steeper hills particularly if you are grinding a bigger gear [mine is 75"]. Also if you are leg breaking a lot this will also add to chain wear and of course winter riding wears it out quicker too.

 

[MrGrumpy]

I agree it would appear from my experience that drive train does not last as long on fixed dependent of course on weather and such like.

 

[mickle]

All other things being equal - a fixed chain will always last longer than a derailleur chain. A major cause of premature chain wear on fixed transmissions is excess chain tension. Though the size of the gear ratio used does play a part a perhaps more significant factor is the relative sizes of chainring and sprocket. A 22 x 11 for example will impose much higher loads on the chain than 44 x 22, though each delivers the same gear ratio.

 

[MrGrumpy]

All other things being equal - a fixed chain will always last longer than a derailleur chain. A major cause of premature chain wear on fixed transmissions is excess chain tension. Though the size of the gear ratio used does play a part a perhaps more significant factor is the relative sizes of chainring and sprocket. A 22 x 11 for example will impose much higher loads on the chain than 44 x 22, though each delivers the same gear ratio.

is their some sort of evidence to back that claim up?

 

[Moodyman]

On the same theme I have hub gears.

The bike comes with an eccentric bottom bracket to help keep a straightish chainline.

The chain's done 1900 miles and has started to sag a little. When I'm putting the power in, and suddenly stop pedalling, the chain slaps on the front chain ring.

I understand that I can re tension chain by adjusting the bottom bracket, but was wondering if I should change the chain?

 

[mickle]

is their some sort of evidence to back that claim up?

Which particular bit are you having trouble with?

 

[MrGrumpy]

Your reasoning for premature chain failure such as excess tension and cog size being the main reasons I understand but I`m not convinced about deraileur chains on your normal multi geared bike lasting less time. Alot can also depend on the power applied by the rider, had one chain snap on my racer but that was down to me making it too short. My fixed however has had several chains they just don`t seem to last?Thinking back to my own thread re the bottom bracket I do seem to be hard on my drive train on the fixed?

 

[mickle]

'All things being equal' (ie the quality of the components, maintenance regime, mileage, conditions and pedal pressure) a properly adjusted fixed chain will last longer because it isn't required to run deflected and to move between sprockets. Even accounting for the longer chain of a derailleur bike.

 

[totallyfixed]

'All things being equal' (ie the quality of the components, maintenance regime, mileage, conditions and pedal pressure) a properly adjusted fixed chain will last longer because it isn't required to run deflected and to move between sprockets. Even accounting for the longer chain of a derailleur bike.

Think I have to disagree with you there, on fixed the chain is constantly under tension because you are always pedalling, with gears you spend a lot of time freewheeling especially in bunch riding. Unless my chains are of different quality between my geared and fixed, and they are the same maker so this must make sense? What I would like to know is what percentage of extra pedalling I do on a typical club run compared with those on gears, I've heard figures given from 10% to 40% but very hard to quantify, on a hilly ride I reckon it has to be at least 25% more.

 

[Smurfy]

Dredging up an old thread here

I've ridden 1100 miles on my chain and it's now reached 12 1/16" for what should measure 12". According to Sheldon that means it's time for a new chain if I wish to avoid wearing the sprocket and chainring. However, looking at the sprocket and chainring, there is some evidence of wear on the sprocket where the rollers contact the teeth, and the chainring has some small burrs on its teeth from extreme loading.

I think the burrs on the chainring could only come from a worn chain, which causes just a few rollers at a time to contact the teeth. But what about the sprocket? Have I trashed it by using White Lightning Clean Ride, rather than a 'proper' wet lube, or is it all down to the chain wear?

 

[al-fresco]

Dunno but it sounds like something's wrong - my last dérailleur chain lasted about 2,200 miles, the one on my fixed bike has sailed past that and at the current wear rate I expect it to be due for replacement about 3,300 - and that's been ridden through the winter. I use the 'mickle method' of cleaning and the cheapest oil I can find in my LBS. (That's currently Weldtite TF2 £2.99 for 125ml.)