So we know that a cassette would last longer if you spead your miles over most or all of the cogs. And I am pretty sure that cog wear accelerates chain wear (and vice versa). Do folks who spread miles over lots of cogs get longer chain life? Which raises the question: how do folks on single speeds and IGHs even get to the end of the driveway without needing to change their chain and cog? Is it just the more robust construction of wider, heavier SS stuff?

Using more different cogs will prolong the cassette life. Also using lower gears do not pivot each chain link quite as much as a higher gear. But then we are getting down to the area of sandpapering a knats hind leg on both sides.

Just lube and keep your chain as clean as possible and use what ever gearing your ride calls for.

Smaller cogs wear out themselves and chains more rapidly since they share the load over fewer teeth and the chain has to make a more severe bend to go around them. So using larger cogs and shifting among them does make the cassette last longer and the more gentle wrap makes chains last longer too.

Single speed/IGH setups tend to use moderate to larger cogs and chainrings ( no 11 or 12T cogs for example) and the chain runs in a completely straight line (assuming proper set up) so there are no side loads.

Thanks. My point is that in windy, flat Houston I mostly haul my ancient ass around with a 2.3 front to back ratio +/- 1 cog and could get that with the 53/23 as well as the 39/17 on my 11-26 10 speed cassette. I do tend to spin pretty high cadences of 90-100 almost all the time. (Let's just ignore for the moment that I might be tempted to use the 53/26 extreme cross chain combo in a headwind.) I should get at least double cassette life if I split my time between the two front rings. I was just wondering if the chain life would also be extended due to the cassette staying in better shape for a longer time. Makes no difference really. You have to replace the chain when you have to replace the chain. It was just an idea that interested me.

The fundamental rule for chain drive applies. Larger sprockets ALWAYS produce more chain life. So if a similar gear can be produced using the inner ring and a particular sprocket in the rear, or the outer ring and a larger one, opt for the outer/larger combination.

The reason is simple, larger sprockets mean lower chain load to transmit the same torque. Also the chain flexes less winding onto larger sprockets (chain flex = 360°/no. teeth), so you have less movement under lighter tension which is a win/win as far as the chain goes. There's also a subtle effect in that there's less chordal action with larger sprockets, which lowers tension spikes.

IMO sprocket condition (within reason) has little impact on chain life since the wear is occurring within the chain as it flexes onto and off the sprocket one link at a time. OTOH chain wear has a large effect on sprocket life because a worn chain doesn't engage smoothly and the engaging roller rubs down the teeth rather than sweeping cleanly into the trough.

If you've ever ridden a ferry, picture the difference between a captain who steers straight down the middle of the slip, and one who misses to one side slightly and rubs the boat down the side of the slip. That's the difference in how new and worn chains engage the sprocket.

So mix sprockets or not, it won't affect chain life, but it will affect cassette life, because the cassettes life is determined by the one most worn sprocket, and not by the average wear

BTW- you bought and paid for gearing to make riding easier. Use the gear that's best for you. Changing how you ride to preserve the chain is backward thinking. Reasonable chain care will give you the best chain life without having to make any other adjustments.

Yep. Makes sense to me. Thanks.

Yes. Also big-big feels faster, because you are in the big chainring!

The one caveat here is that (depending on your RD capacity and chain length) running the outer chainring with big cogs is likely to put more tension on the chain. Take a look at your RD in 53/23 and 39/17. Probably the RD is vertical in 39 and bent forward in 53. That is going to put some extra tension in your chain as the RD wants to come back to neutral position.

Chain care, wear and skipping by Jobst Brandt I have been using an ultrasonic cleaner on my chains and the mileage has more than doubled.

rpenmanparker, I think the angle of the chain during disengagement/engagement will have a wear factor. SS and FG bikes have little or no deviation from a straight chain line.

I haven't kept records, but my impression is that replacement intervals are roughly two chains for one cassette and two cassettes for chain rings. So it does seem that the larger the toothed gear, the longer lived it is, again I can't prove that.

Brad

Sorry, but this is nonsense. First of all, most decent RDs have plenty of turns on the idler cage spring. So the change in tension from the small arc of deflection is fairly small. But the real key is that lower loop tension is near zero compared to the upper tension which is what propels the bike.

Pull the lower loop forward and there's probably a pound or two of tension involved (regardless of gear). Now compare to the upper loop tension driving the bike which can easily run up into hundreds of pounds. (pedal force / crank length X chainring radius)

As I said earlier, larger sprockets mean lower chain tension for any given torque transmission.

OP's real question was does cassette cog wear increase chain wear. When chains wear, the distance between any two rollers with the chain under tension increases. The wear on a cassette does not work the same way. As the cassette wears, the teeth effectively get narrower, but the distance from tooth trailing edge to tooth trailing edge doesn't really change. The change in tooth profile may cause the chain to ride higher on the teeth, but it's not obvious that would have any significant effect on chain wear.

IGH use a 3/32" or 1/8" thick cog .. the needs of a multispeed derailleur is thinner cogs.. and the more speeds = the thinner the chain.

& derailleur bushingless chains, by design, the roller edges are all that is contacting the flange pushed in by punching the holes in the inner link


a old style bushing chain there is a sleeve, that bushing, running the whole width of the inner link,
so the bearing surfaces for roller and pin .. are much larger.