# 11-25 vs 12-25



## PoorCyclist (Oct 14, 2010)

Is the 12-25 better because it doesn't jump from 15-17?
Is losing the 11 a big deal?
Crankset is 34 50...


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## slegros (Sep 22, 2009)

50x11 is a pretty tall gear, you probably wont use it much at all unless you do a lot of high speed descents or sprints, in which case you'd be better off with the 12-25. Flats and shifting winds you'd probably appreciate the 16t cog.


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## kbwh (May 28, 2010)

I've decided to buy a 11-23 for My Campagnolo 11 compact setup to get a straight 11-19 for these 180 km + double paceline rides. With the 11-25 I miss the 18 from time to time.

It's never enough, PoorCyclist, never enough.


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## looigi (Nov 24, 2010)

It depends on you and the riding you're doing, and maybe even the specific course you're riding. You certainly can have several cassettes or a couple of wheels with different cassettes to select among depending on conditions. Here's a graphical gearing calculator you might find helpful.

http://www.gear-calculator.com/#KB=...&KB2=42&RZ2=16&GT2=RLSH&TF=85&UF=2099&SL=2.15


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## scbmx01 (May 31, 2010)

I use a 12-25 for 95% of my riding. I have a 12-27 for riding in the mountains of W. VA and a 11-23 for pancake flat races and sprint training. Even when I have the 11 on, I don't necessarily use it. You would be better off to develop a smooth high cadence spin unless you find yourself lacking in the last kick to the line (in which I would suggest switching to a 53-39).


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## frpax (Feb 13, 2010)

If you could actually tell the difference, then you're better than me.


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## pdh777 (Oct 7, 2005)

I live in Colorado where an 11 comes in handy on descents, here you are either climbing or descending - you do use it here - wouldn't use it in hilly or flat terrain.


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## MR_GRUMPY (Aug 21, 2002)

If you only have a 50 X 12, you'll have a hard time contesting those 40+ mph sprints.


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## frdfandc (Nov 27, 2007)

The difference between the 11-25 and a 12-25 is that you loose the 11 (duh? right?) but you pick up a 16.

I switched because I never used the 11. I hardly ever use the 12 or the 13. But I do use the middle of the cassette alot. So a 16 made sense for my particular requirements.


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## chas0039 (Jun 26, 2007)

I prefer the 11-25 for a compact double because on my terrain, the 12 isn't enough with the 34 front ring and I am constantly shifting. Not so often with the 11.


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## Eric_H (Feb 5, 2004)

I run a 53x39 chainset but I would always choose 12-25 over 11-25. Or basically I would always choose a cassette with a 16T cog, I really notice its absence when I don't have it. This is because I find the jump from 15 to 17 a little too large, but once I'm clear of the 17 then a 2-teeth jump between cogs is just about perfect. So for a 10spd cassette I choose 12-25 or 11-23.


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## Mr. Versatile (Nov 24, 2005)

Unless you're racing, and IME even if you are, you'll never miss the 11. Get the 12-25. It has a noticeably closer mid range ratio, which is where you spend most of your time.


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## ukbloke (Sep 1, 2007)

chas0039 said:


> I prefer the 11-25 for a compact double because on my terrain, the 12 isn't enough with the 34 front ring and I am constantly shifting. Not so often with the 11.


If that's what you really meant to say, I think you're doing it wrong!

Anyway, I have a compact with a lot of different cassettes. The 12-25 is generally on the bike, while the 11-25 is pristine in its packaging on the shelf.


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## rx-79g (Sep 14, 2010)

chas0039 said:


> I prefer the 11-25 for a compact double because on my terrain, the 12 isn't enough with the 34 front ring and I am constantly shifting. Not so often with the 11.


Why would you ever ride in either the 11 or 12 with the 34? 


Historic context for OP: In the olden days, most peoples highest gear was usually a 53x13. When more speeds were offered (6, 7, 8), speedy people started spending one of their few cogs on a downhill/sprint gear - a 12.

On compact systems, a 50x12 is about the same as a 53x13. So if you want the sporty high gear, you get the 11. If you don't need the super big gear, use the closer spaced 12-25. If you'd like the bigger high gear, I doubt you'll miss that 16.


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## Richard (Feb 17, 2006)

I have 50-34/12-25 on my "modern" 10 speed bike. And I have 53-39/12-23 on my 8 speed "vintage" bike. On the vintage, I miss the 16 and need the 53/12 like a hole in the head.

So I seriously doubt I'd need a 50/11 and also suffer the loss of the 16.


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## chas0039 (Jun 26, 2007)

Sorry guys, that is what I need with the geography around here. I spend most of the time in 34 or in 39 with my bikes that have a double front. The only time I need to go to 11 or 12, for that matter, is with the 34 which is why I am not a fan of compact at all. If I have a 12 with my 34, I am constantly shifting to the 50 and then back to the 34 and then back to the 50 and then back to the 34. With the 11, I have a 12 as the second cog so for the few minutes that I need the 11, I have whay I need without having to go through a major shift to 50/16 to get to the same ratio. It is just a royal pain. 

I know many of you still hold that crossing from the inner front gear to the outer rear is forbidden, but with today's hardware, many posters here have said that prohibition is out of date. My chains don't wear out any faster on that bike, nor do my gears. I am not rubbing anything and I kind of look it as though I should get to use the gears that are there when they do what I want. After all, I paid for them and the number of times I would use a 50/11 or 50/12 are near zero. So what good are they if not with the inner front gear?

Anyhow, I know to some this is heresy and I really dislike compact gearing as well, another punishable offense, but I was just passing on what I have been doing for a few years that has worked for me.


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## chas0039 (Jun 26, 2007)

delete


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## ukbloke (Sep 1, 2007)

chas0039 said:


> Sorry guys, that is what I need with the geography around here. I spend most of the time in 34 or in 39 with my bikes that have a double front.


I think you need to reconsider your gearing - you are effectively riding your bike as if it has just a single chain-ring. Assuming that you need that 34 for hills, how about swapping that 50 chain-ring for something smaller that gets you more into the sweet-spot on your cassette? I'm thinking a 46 or a 48, but you'd have to check a gear ratio chart to be sure. You'd also get better front shifting with a smaller ratio change (so less rear shifting to compensate), which might convince you to shift the front rather than using extreme gear combinations with the small chain-ring.


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## Drew Eckhardt (Nov 11, 2009)

PoorCyclist said:


> Is the 12-25 better because it doesn't jump from 15-17?


Yes. And a 13-26 is better than a 12-25 because it doesn't jump from 17 to 19.



> Is losing the 11 a big deal?


No. I had a 50x13 high gear for a decade in the Colorado Rockies (50-34x13-14-15-16-17-18-19-21-23 after switching to 9 speeds and a compact, 50-40-30x13-14-15-16-17-18-19-21 in the 8 speed era). It's good for better than 30 MPH at sustainable RPMs and 36 MPH on sprints. Down-hill it's faster to tuck than pedal. Apart from a few rare occasions (near Chinook tail wind) I'm not going to need anything bigger on flat ground; but do use 50x17/18/19 for a hundred miles a week.


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## chas0039 (Jun 26, 2007)

ukbloke said:


> I think you need to reconsider your gearing - you are effectively riding your bike as if it has just a single chain-ring. Assuming that you need that 34 for hills, how about swapping that 50 chain-ring for something smaller that gets you more into the sweet-spot on your cassette? I'm thinking a 46 or a 48, but you'd have to check a gear ratio chart to be sure. You'd also get better front shifting with a smaller ratio change (so less rear shifting to compensate), which might convince you to shift the front rather than using extreme gear combinations with the small chain-ring.


You are absolutely correct that I would be able to do a better job with a larger inner gear or a smaller outer gear. Unfortunately, Campy individual chainrings are either prohibitively expensive or non-existent. I am limited to 34/50 or 39/53. I was lucky enough to find a triple that will solve the problem on my compact bike and once I wear out the compact ring, I'll be through with it forever. When I discovered the limitations of compact cranks, I made sure my future bikes were set up with 39/53. 

I spent a lot of time trying to figure out something that was more logical, but Campy has predetermined that I want only two choices and the Compact community seems to have decided that I want 34/50. If I wasn't a Campy rider, I would have a ton of chainring options and I would have swapped out long ago. 

Sorry I didn't point that out earlier; it was quite a while ago and I had forgotten the whole long drawn out process that I went through trying to find out some way to fix my compact problem.


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## kbwh (May 28, 2010)

With 10 speed Campagnolo there is the possibility of a 13-29 if your rear derallieur/hanger can handle it.


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## Drew Eckhardt (Nov 11, 2009)

chas0039 said:


> You are absolutely correct that I would be able to do a better job with a larger inner gear or a smaller outer gear. Unfortunately, Campy individual chainrings are either prohibitively expensive or non-existent. I am limited to 34/50 or 39/53.


TA Specialties makes nice rings in 135mm and 110/112.5mm BCDs in pretty much any tooth count you'd want and they're not horribly expensive when ordered from Europe.



> I spent a lot of time trying to figure out something that was more logical, but Campy has predetermined that I want only two choices and the Compact community seems to have decided that I want 34/50. If I wasn't a Campy rider, I would have a ton of chainring options and I would have swapped out long ago.


For 2011 Campagnolo will be selling 10 and 11 speed aluminum and carbon fiber "cyclocross" cranksets in 46-36. I think 46-36x12-13-14-15-16-17-18-19-21-23-25 would be pretty nice road gearing.


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## chas0039 (Jun 26, 2007)

Drew Eckhardt said:


> TA Specialties makes nice rings in 135mm and 110/112.5mm BCDs in pretty much any tooth count you'd want and they're not horribly expensive when ordered from Europe.
> 
> 
> 
> For 2011 Campagnolo will be selling 10 and 11 speed aluminum and carbon fiber "cyclocross" cranksets in 46-36. I think 46-36x12-13-14-15-16-17-18-19-21-23-25 would be pretty nice road gearing.


Thanks for the tips. I might look at those rings if I can find a source across the pond. My budget is limited and I managed to get all my front crank-sets over the last few years for close to $35 each or less, so you can see why the usual price of around $100+ for a single ring was off-putting. Now if I can get their cyclocross rings (for less than $50) to work on a square taper...... oh well, maybe after peace in the middle east.

Edit: I do see that Peterwhitecycles has a wider selection now at a lower price, and Wiggle has exactly what I need at $45. Maybe this is the year I quit cross-chaining?


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## PoorCyclist (Oct 14, 2010)

Thanks guys, my riding consists of climbing, every ride..
on the descent I do try out 11 vs 12 .. seems like the 12 needs to spin alot on the 50 chainring. 90+ rpm. Actually I notice it more on smaller grade 2-4% or tailwind situations, I think I'd prefer 11 to be available.
but then I am not exactly a dare devil, to me descent is just means training over and cruise home. So maybe less speed will help me stay out of trouble


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## tom_h (May 6, 2008)

chas0039,
I am confused by your "compact troubles".

What kind of terrain do you ride?

What are your most common or typical gear choices, when you are on the 34 chainring?


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## Drew Eckhardt (Nov 11, 2009)

PoorCyclist said:


> Thanks guys, my riding consists of climbing, every ride..
> on the descent I do try out 11 vs 12 .. seems like the 12 needs to spin alot on the 50 chainring. 90+ rpm. Actually I notice it more on smaller grade 2-4% or tailwind situations, I think I'd prefer 11 to be available.
> but then I am not exactly a dare devil, to me descent is just means training over and cruise home. So maybe less speed will help me stay out of trouble


Most people have more endurance at high power outputs with increased RPMs, like 95-105 not 80-90 RPM. You'd probably be better off learning to pedal faster for that reason, after which the higher gear becomes irrelevant.


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## TomH (Oct 6, 2008)

I ditched my 10 speed 12-25 for *8 speed* 11-28. The jumps are bigger, but its not a downside for me at all.. its actually quite a benefit. Now shifting a gear actually does something! 

Even on the hilliest terrain, I could ride a standard double with gearing like that.. Ends up being less front shifting. 

Unless you're very trained to keep a specific, determined cadence, you're not going to benefit even marginally from 1 tooth jumps.


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## Drew Eckhardt (Nov 11, 2009)

TomH said:


> I ditched my 10 speed 12-25 for 8 speed 11-28. The jumps are bigger, but its not a downside for me at all.. its actually quite a benefit. Now shifting a gear actually does something!
> 
> Unless you're very trained to keep a specific, determined cadence, you're not going to benefit even marginally from 1 tooth jumps.


I disagree. I won't ride a cassette as wide as 12-25 until I make the 11 (or 12) speed upgrade. I'd junk the 11 cog, skip the 12 cog, and swap the double for a triple to get one tooth jumps especially with insufficient training to sufficiently broaden my comfortable cadence range. I rode a 50-40-30x13-14-15-16-17-18-19-21 in the 8 speed era in the Rocky mountains because one tooth jumps felt good and seemed faster and came to understand why with power meter downloads.

I gave up on bike computers for over a decade after breaking my purple Avocet 45, broke a leg and didn't walk for a few months, was riding a somewhat reasonable 300-400 miles a month recreationally, was insulted by a RADAR sign which suggested I was only going 15 MPH after just half an hour, and figured I might be able to work harder and get faster sooner if I applied science to the problem so I bought a Polar computer with heart rate and cadence.

I found that without any serious training for over a decade my legs were like metronomes - I mostly rode at 83-87 RPM. 

83 RPM in 50x17 takes about 22% more power than 87 RPM in 50x19 (while aerodynamic drag only increases with the square of velocity, you're going farther in the same time so power increases with the cube of velocity). I'd just ride the lower gear at way less power.

83 RPM in 50x18 takes about 2% more power than 87 RPM in 50x19, and keeping the same cadence takes about 18% more power. With the choice I could ride 2 - 18% harder. 

Looking at data I found I could ride longer at the same heart rate at higher cadences so I improved that - I can now spin 100 RPM comfortably. I also added power, because with E-bay and craiglist a Powertap is an inexpensive guy toy.

With a few thousand base miles that year, 1500 miles training with heart rate, and some hundred training with power I noticed that if I kept my cadence over 90 I could still manage 200-220 Watts on my second hour of riding in a day without thinking about it too much but dropping below that I had to pay a lot of attention to avoid a precipitous drop to ~150W and perhaps 80 RPM and even then I'd be averaging 160W over a half hour at the end instead of 190W.

With enough recent stress I'm not going to ride over 100 RPM for more than 10 minutes. It's about a 14 percent power decrease going from a 50x19 at 100 RPM at 20.7 MPH to a 50x18 at 90 RPM at 19.7 MPH and 18% increase speeding up to 21.8 MPH at the same 100 RPM. Between 50x19 and 50x17 it's about a 2% power increase when you drop from 100 to 90 RPM and a 40% power increase at the same RPM - there just isn't any usable overlap in that cadence range.

With more time at higher RPMs it'd be less of an issue.

OTOH, sometimes cadence doesn't matter. I can toodle around with my wife averaging 25W at 40-50 RPM and feel fine indefinitely.


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## TomH (Oct 6, 2008)

> Unless you're very trained to keep a specific, determined cadence, you're not going to benefit even marginally from 1 tooth jumps.


I would say your following 10 paragraphs about cadence, power output and wattage put you into this category  

Im not saying everyone should run a wide cassette. Ive read all the arguments for 10 speed and close cassettes, and they're definitely not wrong. Its just wrong for me. 

Single speed is the same idea. Those guys get one gear and are always in the "wrong" cadence! I kinda enjoy getting only 8 choices and hammering instead of shifting down. 

My real point was that for a recreational rider, "better" isnt always a hard fact. If you get there sooner, you didnt really win, or lose. You're just there sooner.


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## tom_h (May 6, 2008)

*Power & cadence*

Drew,
I don't buy your (apparent) reasoning that certain gear combinations will require more (or less) power, for a given fixed speed -- if I'm following your line of reasoning correctly.

You may be more _comfortable_ at certain cadences, but for exmpl at 20.0 MPH,
50x17 @ 86 rpm
and 
50x19 @96 rpm
are both requiring you to output the same power -- else you wouldn't be able to maintain 20 mph overcoming aero drag, tire Crr, etc.

There have been several controlled academic studies on Power-Cadence relationships, which indicates that over a pretty broad range of cadence, power output does not correlate with cadence. Sometimes that's training dependent, eg a good track cyclist can easily spin 140 rpm & still put out max power, while I'd be bouncing on the saddle.

Certain physiological strengths may favor higher/lower cadence for a given individual -- eg, higher rpm generally seems to place more demand on the cardiovascular system -- but they're not outputting more (or less) power on that basis alone.

If I have misunderstood your argument -- sorry! ;-)


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## rx-79g (Sep 14, 2010)

The reason I like a high gear for use downhills (like 50x11), is that you can put some power back into the pedals WITHOUT having to spin at 90+ RPM. Which is a really nice break after a long climb.


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## Drew Eckhardt (Nov 11, 2009)

tom_h said:


> Drew,
> I don't buy your (apparent) reasoning that certain gear combinations will require more (or less) power, for a given fixed speed -- if I'm following your line of reasoning correctly.


They don't. My point is that higher cadences can make it practical to put out the same power for longer and one tooth gaps towards the bigger cogs allow that without running out of RPM. The reasons could be physiological or just psychological. Either way riding faster and burning more calories at the same perceived effort is a win. 



> You may be more _comfortable_ at certain cadences, but for exmpl at 20.0 MPH,
> 
> 50x17 @ 86 rpm
> and
> ...


I can push 200-220W at 96 RPM or 86 RPM with a lot of sweating and some grunting (Golden Cheetah calculates critical power of 203W). The power meter doesn't see a difference and speed will be the same when position/slope/wind/pavement/etc match. But with fatigue from earlier in the ride, day, or week when I spin 96 RPM I stay there - maybe it's 98 RPM and 190W down a dip, or 92 and 260W up a bump. 86 RPM and 220W drops to 80 RPM and 170W on flat ground without feeling any different, I look at the power display and speed up, and the same thing happens again - the ride plot looks like a reverse sawtooth wave instead of a flat squiggle. With a group to follow or watching the power display instead of the road I might physically be able to maintain the same power but on a solo ride maintaining the same effort at lower cadence isn't practical.

For 10 minutes when fresh or at 150-170W with the same sort of preceding effort it doesn't matter.



> There have been several controlled academic studies on Power-Cadence relationships, which indicates that over a pretty broad range of cadence, power output does not correlate with cadence.


I read the summaries from some of the studies. I also read anecdotes from guys who could sustain more power at 80 RPM than 90 or 90 than 80 and about the racer in _Training and Racing with a Power Meter_ who got dropped whenever he needed to spend over five minutes above threshold power pedaling under 75 RPM. 

So I figured I'd try more RPM and manged to maintain power a lot better as fatigue increased with only 300-400 more miles under my butt. Most importantly squeezing an extra 100 kilojoules out of my evening commute means I can eat more of my wife's gourmet cooking over the weekend.


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## ziscwg (Apr 19, 2010)

looigi said:


> It depends on you and the riding you're doing, and maybe even the specific course you're riding. You certainly can have several cassettes or a couple of wheels with different cassettes to select among depending on conditions. Here's a graphical gearing calculator you might find helpful.
> 
> http://www.gear-calculator.com/#KB=...&KB2=42&RZ2=16&GT2=RLSH&TF=85&UF=2099&SL=2.15


I found that a useful tool.


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## Drew Eckhardt (Nov 11, 2009)

ziscwg said:


> I found that a useful tool.


Mike Sherman's calculator 

http://home.earthlink.net/~mike.sherman/shift.html

has a section which accepts cadence ranges so you can see where the gaps are.


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## apoint (Nov 22, 2010)

I was always told with a compact 50x34 you need the 11x25 so you dont spin out on top speed? True or not?


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## spade2you (May 12, 2009)

apoint said:


> I was always told with a compact 50x34 you need the 11x25 so you dont spin out on top speed? True or not?


Depends on how strong you are and your definition of spinning out. For the average Joe, a 50x12 is generally plenty. For a bunch sprinter? Maybe not so much. I don't think I've spent much time in 50x11 gearing on my road bike. On my TT bike, I've only touched the 53x11 with some substantial wind to my back.


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## Drew Eckhardt (Nov 11, 2009)

apoint said:


> I was always told with a compact 50x34 you need the 11x25 so you dont spin out on top speed? True or not?


Not.

I've had a 50x13 high gear since 1995 or 1996 (currently 50-34 x 13-23). Worked fine for the Rocky Mountains and adjacent plains solo and on group rides. The high gear is good for sustained speeds over 30 MPH and sprints over 36. Generally by the time you're going that fast it's on a steep enough incline that you'll go faster by stopping pedaling and getting more aerodynamic. It wasn't enough with near Chinook tail winds, but with a 40 MPH tail wind I wasn't too concerned about how quickly I wasn't getting to work.

If I ever manage to increase my power over 137% (the extra oomph needed to sprint 36 MPH instead of 27) I'll either re-evaluate or work for 140 RPM.

Although for the UCI hour record I might keep it; Boardman found it sufficient (in the form of 54x14) for 49.441 KPH.

There are some situations where you might need a bigger gear like time trialing with a tail wind but it's far from universal, and most people would do better just learning to spin faster.


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## apoint (Nov 22, 2010)

On down hills my 53- 12 I feel I'm spinning out. So I would think on down hills the 50-11 would be appropriate. Its not a gear that would really get used till you hit a down hill for top end.
So I guess I should stay with a 39x53 and 12-25.?


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## PoorCyclist (Oct 14, 2010)

Drew Eckhardt said:


> Mike Sherman's calculator
> 
> http://home.earthlink.net/~mike.sherman/shift.html
> 
> has a section which accepts cadence ranges so you can see where the gaps are.


great program. while I do see the 11 gives a few more mph, it does show the 16T gear fills a good void of speed ranges.


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## chas0039 (Jun 26, 2007)

tom_h said:


> chas0039,
> I am confused by your "compact troubles".
> What kind of terrain do you ride?
> What are your most common or typical gear choices, when you are on the 34 chainring?


Well, we have kind of beat this to death, but I am not one to ignore a direct question.

Most of the time I am going up gradual to moderate hills followed by gradually up angled flats. The slight downhill spurts I encounter are brief and this is when I slip into the 11-12 cog. I am rarely in these cogs for more than a minute. Most of the time I am in the 14-15-17-19 cogs and the front 34. To accomplish the same thing in the 50 front ring, I would start out at 23 and quickly run out of cogs at 25. For a while I considered a custom set of cogs but there is no 27 or 28 Campy choice (29 is more than necessary) and spending all my time in 50/26 seems extreme just to avoid a few seconds in 34/11. As mentioned earlier, going to 37 or 38 on the front gear would make a big difference but there are very limited options fitting Campy. This is why I set up all the other bikes I built subsequently with 39, although this is just a touch too many teeth.

In the end, I figured the small amount of time I spent crosschained was not worth the trouble or expense of a major change in any other gear. After 4-5 years there have been no problems at all, and now I know not to ever touch a compact front again.


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