sysrq

Another one besides Campagnolo Ekar is Rotor 12/11-39 but that one is also too expensive compared to 105 11-34 Shimano.

Ron Damon

Gearing may be linear in its progression, mathematically & geometrically, but will you experience and feel it as such? Human cognition is not linear. Take sound and light perception, for example. For something to feel linear, it may well have to be logarithmic or even exponential.

bwilli88 

Most linear progression would be the Shimano 12-36 9 speed cassette.
OP is looking at logarithmic.

Darth Lefty 

It’s summer! Go ride your bikes and save this stuff for February

DaveSSS 

I've not had any problem with SRAM's 10T sprocket. The 10 gives more total range. I have a 46/30 crank and 10-36 cassette that produces a 552% range. I use the 46/10 only on descents, but it's great in the 32-40 mph range. There's no way you can feel a few watts lost at that speed. Campy has 10T sprockets on their latest Super Record wireless group and 9T on Ekar. Ekar has been very successful.

mschwett 

knew the facts, but hadn't really thought about this in this way. makes a ton of sense and a clear explanation. i'm riding the 12s 11-34, because although physics is physics i'm too slow to climb really big hills without the 34

PeteHski

I agree. If I lose a few Watts when pedalling a 48/10 I don’t really care. It’s not a gear that gets much use on my bike and certainly not when power is critical.

tomato coupe

On the other hand, why throw away any watts if you don't have to?

mschwett 

while you don’t “have to” of course, on my 1x bike the gains from a more appropriate low end (10% smaller small cog, 10% smaller chain ring) more than outweigh the .5-1% loss from 10t vs 11t. in reality it’s probably less than that when you take into account the smaller chain ring and losing the other chain ring and FD completely.

cyccommute 

Reciprocal of the form y=k/x where k is a given chainring and x is the cog. This graph is for all gear combinations from 11 to 37 (in one tooth increments) with a 44 tooth chainwheel.

tomato coupe

Yeah, it’s hard to do a 1x without going to small (9 or 10) cassette cogs, but they aren’t really needed in a 2x setup.

mschwett 

agreed, and the differences in efficiency and weight are so small that there seem to be much better reasons to decide one way or the other. i have a 2x road bike and a 1x road/gravel bike (with a 10t) and they each seem fairly well suited to what i use them for. efficiency is very low magnitude in the pros/cons list.

PeteHski

I can't say I notice any difference. My other bike with Shimano has a 50/11 high gear. I simply don't use those gears enough to care and I would be soft pedalling downhill anyway.

beng1

It is funny how at the same time we can obsess over what cogs are in a freewheel or cassette, and at the same time be thrilled with a single-speed bicycle.

I have a lot of freewheels laying around some with one-tooth jumps and some a bit wider and standard ones with wider jumps, they all have their place depending on what sort of riding is being done and how many hills are on the ride. I think it helped perspective a lot putting a thousand miles on a single-speed road bike the first half of this year, and although I am in my 60s I am able to go 18mph easily enough on the flat with the bike, but also hump it up some pretty long 5% grades and even a 7%+ grade in my town that is one block long. But then when I jump on my Marin with it's 24 speeds and a relatively close XTR "cyclocross" rear cassette, I can still complain to myself how it has too big a jump between two of it's cogs.

This lets me know that when the gearing of my bicycle is bothering me, then it most likely to be a combination of being old, being out of shape, and being short on sanity.

Leisesturm

Has it been noted in this thread yet that smaller chainwheels and cogs wear much faster than larger ones and that that probably outweighs any weight savings?

GhostRider62

No kiddin

$881 for Sram rings with PM.

Segue to the Wax immersion thread .....

sysrq

When legs get tired during long distance commuting (80-160km) then smaller steps between gears feel handy depending on a specific conditions. Too fast or too slow cadence can start to feel annoying.
Single speed feels smoother and paradoxically more efficient on inclines, but at the same time leaves you with a limited aftertaste, especially when not being able to take full advantage of that rare tailwind. Have been riding single speed 40km max only on a nearly flat roads so it's hard to come up with a more realistic conclusion.

sysrq

For some weird reason this stuff comes up most often in the summer. Most of the cycling has always happened during autumn and spring when there are lower temperatures and humidity. Wildlife and traffic also seems calmer at that time so it doesn't increase the anxiety as much while riding.

Kapusta

I would agree that for most applications this is true, but it’s actually fine for most people for MTB use.

42x13 is just a smidge taller than 32x10 which is a very common top gear for modern 12 sp mtbs. Most modern mtbs run a 10t small cog with a front ring ranging from 28-34t, 30-32 being the most common on stock builds. And just a few years ago before 12sp, 11t was the smallest cog, and 32x11 was a common high gear.

PeteHski

So is the 48/10 on my SRAM bike really going to wear out "much faster" than the 50/11 on my Shimano bike? Or is it going to matter far more whether or not I ride them in crappy road conditions or how often I clean and lube them?

beng1

The trick to riding a single-speed is to gear it so you can go up most hills in your area, so that you may have to walk up a few hills in your area, and to grow up enough that you don't care that you have to walk up an occasional hill or have a lower speed on the flat. It is all exercise and it is all fun for the adult.

DaveSSS 

If you have a 50/11, then a 46/10 is about the same. A 48/10 is like a 53/11. The rate of wear won't be significantly different. SRAM's expensive rings with power meter aren't a necessity. There are other ways to measure power, like pedals or crank arms with power meter.

I suspect that most people who have power readings don't race or train seriously, so the power info is just another piece of worthless data.

As for cassette wear, a 10 won't be the sprocket that wears out first.

The smaller rings are not for saving weight, they're for combining with the larger range cassettes to get more range with similar gear ratios.

I use cheap grx cranks with my SRAM force drivetrains.

Kapusta

I spend so little time in my smallest cogs that the wear rates of 10t vs 11t vs 12t are really a non-issue. I’m going to wear some other cogs first.

In addition to the little time spend in my smallest cog, I am also not generally pushing it all that hard as I am just topping my speed off going down hill.

Leisesturm

It's not just the small tooth cogs that wear faster. The smaller tooth chainwheels of a Compact or MTB crankset wear faster than the larger ones of a Road set. On Tandems where the timing rings are the same size and in a zero offset chainline there is a noticeable difference between how a 38T pair and a 42T pair wear over a single riding season. Granted, the average person does not ride enough miles a year for it to be a financial make or break, but I just found it interesting that it has been completely overlooked.

Leisesturm

I'm going out on a limb and theorizing that the 32x10 top gears are being used on 29'er MTB's and not 26" MTB which is what I was referring to. But the point of my post was that we didn't even know that the o.p. is using the bike off-road.