# what's so special about 16t cog?



## tjjm36m3 (Mar 4, 2008)

So what is so special about the 16t cog? My campy 10spd 11-25 cassette is missing this 16t cog, but it shifts and rides fine between 15t, 17t and the 19t cog. I keep hearing the 16t as the sweet spot. Is it because it is right in the middle of a standard 12-25 cassette or there's more to it?


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## MR_GRUMPY (Aug 21, 2002)

tjjm36m3 said:


> So what is so special about the 16t cog? My campy 10spd 11-25 cassette is missing this 16t cog, but it shifts and rides fine between 15t, 17t and the 19t cog. I keep hearing the 16t as the sweet spot. Is it because it is right in the middle of a standard 12-25 cassette or there's more to it?



For most riders, a 15 is a little large to spin on a solo ride. If you're in a 17, and you want to push it a little harder, you go to the 16. If you don't have a 16, you're stuck with using a 15, or spinning the 17 at a high rate.


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## Guest (Dec 23, 2009)

I think its a bit of the old wanting what you don't have. Not that I don't like a nice tight cassette now and then.


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## tjjm36m3 (Mar 4, 2008)

kytyree said:


> I think its a bit of the old wanting what you don't have. Not that I don't like a nice tight cassette now and then.


Thanks, apparently you read my other post.  Yeah 11-23 is good for most rides especially on the flats, but on some of the tougher climbs I miss the 25t.


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## Mr. Versatile (Nov 24, 2005)

Ahhh yes! This conversation takes me back to the days of yesteryear when we all had 5 spd straight blocks of 14, 15, 16, 17, 18 with 52X42 up front, and friction downtube shifters. Not too long after that new fangled 6 spd stuff started up.


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## zriggle (Apr 16, 2008)

Mr. Versatile said:


> Ahhh yes! This conversation takes me back to the days of yesteryear when we all had 5 spd straight blocks of 14, 15, 16, 17, 18 with 52X42 up front, and friction downtube shifters. Not too long after that new fangled 6 spd stuff started up.


Ha! I remember when we only had two gears, and shifted with a rod!

And the Alps were uphill BOTH ways!

(Sorry, I couldn't resist!)


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## SwiftSolo (Jun 7, 2008)

I ride campy 11 and combined an 11-25 with a 12-27 to make a 11-27 cassette. I had to give up the 16 tooth cog. The cassette shifts flawlessly but I can tell you that there is a flat spot without the 16. Instead of 11-12-13-14-15-16-17-19-21etc. I'm now at 11-12-+13-14-15-17-19 etc. The span between the 15 and 17 is just too large on the flats and the cadence jump is too big. I really miss the 16 and am now motivated to lose enough weight to eliminate the need for the 27 so I can again close up that 15-17 span with the 16. We do a lot of pretty steep climbing and I currently need the 27.

In a perfect world we'd have 12 speed cassettes so I could have the 11, the 16 and the 27(but then again, I could stand to lose 15 lbs).


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## tom_h (May 6, 2008)

17 to 15 cog is 13.3% "harder", _irrespective_ of the front chainring. 

Too big of a change in gearing (cadence) for most people, especially considering 15-16-17 is used a lot when riding in flat or rolling terrain.


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## C-40 (Feb 4, 2004)

*right..*

It's all about the percentages. The smaller cogs have about an 8% difference between them, but the percentage change gets smaller as the cogs get larger. The 16-17 shift drops to only 6%, but the alternative of deleting it produces twice the percentage change.

Some people whine about not having an 18T too, but the 18-19 shift is an even smaller percentage. It's most often useful on flatter terrain. I had an 18T for many years, but I dropped it with a 12-25 10 speed back in 2000 and haven't had one since.


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## FBinNY (Jan 24, 2009)

C-40 is right that it's about percentage changes between gears. At some point with a wider range cassette you have to give up the single tooth differences and accept larger percentages between shifts.

As for where the so called sweet spot is, you can correct this for your personal needs by changing chain rings, so that you do most of your riding in the upper mid-range of your cassette, where the steps are smallest.

If the terrain where you ride isn't very hilly, you might abandon the traditional 53/39 or 53/42 and use chain rings with a smaller difference so that a front shift is equal to 1-1/2 steps of the rear. This allows effective use of both chain rings in the mid range of the cassette creating added useful gears.


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## Mel Erickson (Feb 3, 2004)

Something else to consider. How often do you need/use the 11t cog versus how often do you need/use a 16t cog? Which would be more valuable to have for your normal riding, assuming you only use one cassette?


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## Guest (Dec 23, 2009)

Mel Erickson said:


> Something else to consider. How often do you need/use the 11t cog versus how often do you need/use a 16t cog? Which would be more valuable to have for your normal riding, assuming you only use one cassette?



Good point, certainly has its benefits for the right situation.


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## mohair_chair (Oct 3, 2002)

tjjm36m3 said:


> So what is so special about the 16t cog? My campy 10spd 11-25 cassette is missing this 16t cog, but it shifts and rides fine between 15t, 17t and the 19t cog. I keep hearing the 16t as the sweet spot. Is it because it is right in the middle of a standard 12-25 cassette or there's more to it?


I used to hear about the wonderful 16t all the time. Then when I went to 10-speed, I got one. It's a fine gear, but, meh. The heavens did not open and the angels did not sing. I'm not saying I hated it, it just didn't live up to the hype as the "sweet spot." I was perfectly happy without it, and I was no happier with it.


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## FBinNY (Jan 24, 2009)

mohair_chair said:


> I used to hear about the wonderful 16t all the time. Then when I went to 10-speed, I got one. It's a fine gear, but, meh. The heavens did not open and the angels did not sing. I'm not saying I hated it, it just didn't live up to the hype as the "sweet spot." I was perfectly happy without it, and I was no happier with it.


The whole concept of one supposed sweet spot is patently ridiculous. 

It assumes we all have the same legs, ride the same way, at the same speed on the same terrain. Perfect gearing is something that is different for different people and depends on their riding style, condition, and the terrain they ride in. 

Back in the Bronze Age before index shifting imposed gear selection limitations, each rider used a gear chart and set up his own bike according to his own needs and preferences. Of course back then we were all riding 10 speed (as in 5x2) so our options were a bit more limited.


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## wim (Feb 28, 2005)

FBinNY said:


> Perfect gearing is something that is different for different people and depends on their riding style, condition, and the terrain they ride in.


And don't forget the day of the week. One day, you can barely get out of your own way. On the next day's ride, you think about going to the big ring—only to realize that you're already on it.


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## tjjm36m3 (Mar 4, 2008)

Mel Erickson said:


> Something else to consider. How often do you need/use the 11t cog versus how often do you need/use a 16t cog? Which would be more valuable to have for your normal riding, assuming you only use one cassette?


This is what I have, one wheelset with 11-25 cassette and another with 11-23, both 10spds. 

That's right I don't use the 11t as much as the 16t on the 11-23 cassette. The 11-23 is great for flats but sometimes with steep climbs I need the 25t. So nowadays I favor riding my wheelset with the 11-25 more because on occasions my group ride would decide on the last minute whether to do climbs or not. But the one reason I like the 11t instead of going to a 12-25 (where I have both 16t and 25t) is that I usually like to ride in the 39 chainring until down to the 13t. If I have a 12-25, I can only go to 14t before coming to some front deailleur rub due to cross-chaining.


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## SystemShock (Jun 14, 2008)

tjjm36m3 said:


> So what is so special about the 16t cog?
> 
> My campy 10spd 11-25 cassette is missing this 16t cog, but it shifts and rides fine between 15t, 17t and the 19t cog. I keep hearing the 16t as the sweet spot. Is it because it is right in the middle of a standard 12-25 cassette or there's more to it?


I think a lot of it is the nature of riding on the flats vs doing climbs.

On a climb, a 2-tooth jump between cogs isn't usually a big deal.

Assuming you keep the same cadence, shifting up a cog in your climbing gears results in around 10% change in power output needed, more or less. The resistance you face on climbs is mostly linear.

But on the flats, you're fighting against _wind_ resistance. And that doesn't go up linearly, you need something like double the power to go 30% faster (depending on whose power calculator you believe).

So, 2-tooth jumps in the flatland gears can be an issue. Say you want to shift up from the 17, and your next gear is the 15. Assuming you keep the same cadence, you'll end up going 13% faster. But that requires about 40% more power. 

But you had a 16, then shifting up would result in you going only 6% faster (if same cadence), and needing only about 20% more power. 

However, should be noted that some ppl are fine with 2-tooth jumps in flatland gears, figuring it makes them a stronger, better-adapted rider not to have the 'perfect' gear always at hand. In fact, the fixie movement is sort of that taken to its final extreme.
.


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## SystemShock (Jun 14, 2008)

zriggle said:


> Ha! I remember when we only had two gears, and shifted with a rod!


Sounds like code for something naughty. Don't want to know.  
.


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## Kuma601 (Jan 22, 2004)

For me, just comfort. Back in the 6spd days, the bike had a 13-18. Then like now, most the time is spent in the 18-15 cogs. I'd miss the 16 but to compensate I'd swap the inner chainring to get a comparable gear ratio on another cog.


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## Mel Erickson (Feb 3, 2004)

tjjm36m3 said:


> This is what I have, one wheelset with 11-25 cassette and another with 11-23, both 10spds.
> 
> That's right I don't use the 11t as much as the 16t on the 11-23 cassette. The 11-23 is great for flats but sometimes with steep climbs I need the 25t. So nowadays I favor riding my wheelset with the 11-25 more because on occasions my group ride would decide on the last minute whether to do climbs or not. But the one reason I like the 11t instead of going to a 12-25 (where I have both 16t and 25t) is that I usually like to ride in the 39 chainring until down to the 13t. If I have a 12-25, I can only go to 14t before coming to some front deailleur rub due to cross-chaining.


12/25 cassette would be best for your situation. Really, the reason you have two chain rings is to use them. What in the world is wrong or hard about shifting to the big ring when you need too?


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## SystemShock (Jun 14, 2008)

SwiftSolo said:


> In a perfect world we'd have 12-speed cassettes so I could have the 11, the 16 and the 27


Oh, don't worry. Those are coming. In fact, God help anyone who tries to get in the way of that train. 

The bigger Q: Will they be dumb enough to go for 13- or 14-speed cassettes eventually? Shimano already has a patent on a 14-cog setup, apparently.

For those of you who simply _had_ to have a 11-12-13-14-15-16-17-18-19-21-23-25-27-29. :shocked:
.


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## Hank Stamper (Sep 9, 2009)

wim said:


> And don't forget the day of the week. One day, you can barely get out of your own way. On the next day's ride, you think about going to the big ring—only to realize that you're already on it.


yup, and to go the next level: hour to hour or mile to mile. What might feel right at mile 10 is probably way to high at mile 90 through the mountains.


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## SwiftSolo (Jun 7, 2008)

Somehow, you guys missed this extremely complex mathematical point. There is nothing magic about the 16t. If you are riding on a 6 speed cassette, you'll never even think about it because your cadence will jump or drop 25 rpms with each shift anyway and the pain associated with that on a long hard ride will be normal and will have long since numbed your brain.

But, if you can still do math, you'll find that the one big cadence jump in a standard 10 speed climbing cassette happens during the 15-17 shift. Nowhere else will you feel such a large change in pressure and cadence. This all assumes that you have a near normal cassette. 

To summarize, small cadence jumps GOOD, large cadence jumps BAD


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## Dave IV (Jan 20, 2009)

Mr. Versatile said:


> Ahhh yes! This conversation takes me back to the days of yesteryear when we all had 5 spd straight blocks of 14, 15, 16, 17, 18 with 52X42 up front, and friction downtube shifters. Not too long after that new fangled 6 spd stuff started up.



Ahhhhhhh, the good, old days. I had, and still do live in a state with mostly flat terrain, so I swapped the 42 for a 47.


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## SystemShock (Jun 14, 2008)

SwiftSolo said:


> *Somehow, you guys missed this extremely complex mathematical point. *There is nothing magic about the 16t. If you are riding on a 6 speed cassette, you'll never even think about it because your cadence will jump or drop 25 rpms with each shift anyway and the pain associated with that on a long hard ride will be normal and will have long since numbed your brain.
> 
> But, if you can still do math, you'll find that the one big cadence jump in a standard 10 speed climbing cassette happens during the 15-17 shift. Nowhere else will you feel such a large change in pressure and cadence. This all assumes that you have a near normal cassette.
> 
> To summarize, small cadence jumps GOOD, large cadence jumps BAD


I thought post #17 hit that and then some.
.


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## Deesmash101 (Dec 18, 2020)

mohair_chair said:


> I used to hear about the wonderful 16t all the time. Then when I went to 10-speed, I got one. It's a fine gear, but, meh. The heavens did not open and the angels did not sing. I'm not saying I hated it, it just didn't live up to the hype as the "sweet spot." I was perfectly happy without it, and I was no happier with it.


Sounds like you got power. I train with 47 - 13t track bike and its a very hard gear but very fast if you got the strength. Im from San Jose mostly flat I've been riding 10+ years. You gotta train and get stronger everyday no half stepping. Much respect


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## Kerry Irons (Feb 25, 2002)

Deesmash101 said:


> Sounds like you got power. I train with 47 - 13t track bike and its a very hard gear but very fast if you got the strength. Im from San Jose mostly flat I've been riding 10+ years. You gotta train and get stronger everyday no half stepping. Much respect


Congratulations on reviving an 11 year old thread. I'm sure the OP has been waiting all this time for the input on track bikes, since he is a roadie.


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## Lombard (May 8, 2014)

Nothing like a good thread dredge. Almost as satisfying as a good poop.


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