Compact 11/25 or 12/25...which way to go?

[teamgomez]

Picked up my first compact drivetrain (on an SL2 Tarmac Sworks/Record)- comes with a campy record 11/23 and a miche (should be spelled H-u-f-f-y) 11/25. Shifting on the campy cassette was buttery smooth/no hangups; shifting on the miche (plastic spacers? YGTBFSM) leaves something to be desired and thought I'd just buy a new 11/25 until...I learned that a) these damned campy cassettes go for some serious yang and b) the 11/25 loses the 16 cog. I plotted the different final drive ratios on the attached and it appears that I spend most of my time btwn 2.52, 2.79 and 3.12 on my former steed (12/27 on a 53/39 noted in brown). The 11/25 goes 2.63, 2.94 and jumps to 3.33 due to a loss of the 16 tooth gear. (color codes- yellow/green is max offset I'll accept/grey I won't do/too much off-axis on the chain)

So here's the question- will I be pining for that 11 tooth cog that gives up 2.66'/revolution or 2.5mph on the top end with equivalent rpm??? A buddy who rides a compact said he just goes with the 12/25 and is fine with it. I'm a bit of a fan of the 25 cog with our local 1.3miles/14% hill that leads to Satan's gate...my max watt output (estimated via sport track) is 297 watts for that particular interlude to Hell...so should I just suck it up with the 11/23 Campy buttery-smooth record and tell myself I'm building strength for every 10" farther I have to push per pedal stroke (23 vs 25) and send the Miche out with the trash?

If these damned campy cassettes were only $40 a piece, I would just outfit the stable and ride what I feel...but at nearly $400 a copy, I want to nail this down.

Thanks!

 

[alienator]

I'd get the 12-25 cassette. There really isn't a need very often at all for an 11 tooth.

 

[teamgomez]

so how big does the downhill need to be in order to justify bumping up to the 11?

We've got the Sea Otter Classic out here with a race at Laguna Seca. Overall drop on the track is only 250' and we do 6-ish laps...max speed off the corkscrew and raging downhill at 49 mph (my gps max for the track) should yield best time (I think...corkscrew is the type 1 turn for bikes at Laguna....leads to the longest 'straight') so I don't want to give anything up there. I guess it boils down to whether or not the 16 is worth it on the 'flats' (turn 3 to 5).

next question is go record or just get a chorus 12-25 ('cuz I hear the wear delta WRT the Ti/Al is significant)?

 

[alienator]

Chorus cassette shifts exactly like the Record cassette....so does Centaur and Veloce. Centaur and Veloce are the least expensive, which makes them the perfect racing answer.

 

[Peter@vecchios]

Picked up my first compact drivetrain (on an SL2 Tarmac Sworks/Record)- comes with a campy record 11/23 and a miche (should be spelled H-u-f-f-y) 11/25. Shifting on the campy cassette was buttery smooth/no hangups; shifting on the miche (plastic spacers? YGTBFSM) leaves something to be desired and thought I'd just buy a new 11/25 until...I learned that a) these damned campy cassettes go for some serious yang and b) the 11/25 loses the 16 cog. I plotted the different final drive ratios on the attached and it appears that I spend most of my time btwn 2.52, 2.79 and 3.12 on my former steed (12/27 on a 53/39 noted in brown). The 11/25 goes 2.63, 2.94 and jumps to 3.33 due to a loss of the 16 tooth gear. (color codes- yellow/green is max offset I'll accept/grey I won't do/too much off-axis on the chain)

So here's the question- will I be pining for that 11 tooth cog that gives up 2.66'/revolution or 2.5mph on the top end with equivalent rpm??? A buddy who rides a compact said he just goes with the 12/25 and is fine with it. I'm a bit of a fan of the 25 cog with our local 1.3miles/14% hill that leads to Satan's gate...my max watt output (estimated via sport track) is 297 watts for that particular interlude to Hell...so should I just suck it up with the 11/23 Campy buttery-smooth record and tell myself I'm building strength for every 10" farther I have to push per pedal stroke (23 vs 25) and send the Miche out with the trash?



If these damned campy cassettes were only $40 a piece, I would just outfit the stable and ride what I feel...but at nearly $400 a copy, I want to nail this down.

Thanks!

Gotta ask whether you will use a 16t or a 11t more often. I would vote for a 16t. My rig is a 50/13 highest gear and it's just fine and dandy. few need a 11t, even with a compact. A 50/12 is still a huge gear.

BTW-10s? Veloce 10s cogsets are about $100. Cassettes are consumables. Lower end ones last the same, work the same. No reason to get a big $ one, chain either.

 

[alfeng]

Picked up my first compact drivetrain (on an SL2 Tarmac Sworks/Record)- comes with a campy record 11/23 and a miche (should be spelled H-u-f-f-y) 11/25. Shifting on the campy cassette was buttery smooth/no hangups; shifting on the miche (plastic spacers? YGTBFSM) leaves something to be desired and thought I'd just buy a new 11/25 until...I learned that a) these damned campy cassettes go for some serious yang and b) the 11/25 loses the 16 cog. I plotted the different final drive ratios on the attached and it appears that I spend most of my time btwn 2.52, 2.79 and 3.12 on my former steed (12/27 on a 53/39 noted in brown). The 11/25 goes 2.63, 2.94 and jumps to 3.33 due to a loss of the 16 tooth gear. (color codes- yellow/green is max offset I'll accept/grey I won't do/too much off-axis on the chain)

So here's the question- will I be pining for that 11 tooth cog that gives up 2.66'/revolution or 2.5mph on the top end with equivalent rpm??? A buddy who rides a compact said he just goes with the 12/25 and is fine with it. I'm a bit of a fan of the 25 cog with our local 1.3miles/14% hill that leads to Satan's gate...my max watt output (estimated via sport track) is 297 watts for that particular interlude to Hell...so should I just suck it up with the 11/23 Campy buttery-smooth record and tell myself I'm building strength for every 10" farther I have to push per pedal stroke (23 vs 25) and send the Miche out with the trash?

If these damned campy cassettes were only $40 a piece, I would just outfit the stable and ride what I feel...but at nearly $400 a copy, I want to nail this down.

Thanks!

I don't know how good-or-bad MiCHE (and/or, IRD) cassettes are ...

Regardless, FYI, you can simply restack your 11-23 Record cassette by putting the 25t Miche on the freehub body [the MICHE cogs are separate, right?], first, & eliminate whichever of the smaller, loose cogs you feel you can live without.

BTW. If you are truly concerned about a "racing" set up, then WHY are you handicapping your racing bike with a 50t chainring? Did you change your inner to a 36t or 38t chainring?

49MPH?!? I don't think anyone is pedaling at that speed except in a Velodrome.

 

[daveryanwyoming]

...BTW. If you are truly concerned about a "racing" set up, then WHY are you handicapping your racing bike with a 50t chainring? ...

Gotta disagree with this sentiment. I've been racing very well on a compact crank setup for the past three seasons. I don't get into the 11 a lot, but even a 50:12 is a substantial gear, with 10 speed clusters the steps between gears are still plenty tight and the low end has come in very useful in a number of races. It allows me to run an 11-23 casette for most events and an 11-25 when there's really steep sustained climbing and it allows me to stay in the big ring for most racing even for a fair amount of the climbing. Even in flat crits the compact works great, sure it might mean I'm riding one cog higher than I would otherwise so there's probably a theoretical issue with chainline but in practice it makes no difference. I only ride bigger rings on my TT bike.

There's nothing wrong with racing on compact gearing, it does not put you at a competitive disadvantage.

-Dave

 

[teamgomez]

I wish I could say I was 'on the pedal' at 49...but that would be about 135 rpm (!) and my 'tactic' is to get as much speed as possible sooner rather than let it build over the distance of the downhill (longest straight).

I'm new to the racing side...unsure what the 'handicap' is mentioned above w/ a 50 tooth. The bike has a compact up front (50/34 on a 175mm crank).

 

[alienator]

I wish I could say I was 'on the pedal' at 49...but that would be about 135 rpm (!) and my 'tactic' is to get as much speed as possible sooner rather than let it build over the distance of the downhill (longest straight).

I'm new to the racing side...unsure what the 'handicap' is mentioned above w/ a 50 tooth. The bike has a compact up front (50/34 on a 175mm crank).

There is no handicap. Ignore the comment.

 

[alfeng]

I wish I could say I was 'on the pedal' at 49...but that would be about 135 rpm (!) and my 'tactic' is to get as much speed as possible sooner rather than let it build over the distance of the downhill (longest straight).

I'm new to the racing side...unsure what the 'handicap' is mentioned above w/ a 50 tooth. The bike has a compact up front (50/34 on a 175mm crank).

I love the "Alpine" gearing that the so-called "compact" cranks use ... so, don't presume that I think that there is anything wrong with a 50/34 crank for normal riding ... OR, racing.

But, you (the OP) seem to have made such a big deal about the drivetrain's minutia rather than sorting the particulars out on the road that one has to presume you are trying to optimize your bike's configuration.

Personally, since I don't race, I just want a low enough low + a bail out gear ...

For most people a 4:1 ratio is MORE than enough for a high gear.

Regardless, since you are setting your bike up for racing, you need to know that the shifting will always be marginally faster and/or infinitesimally better between the inner & outer chainrings on a "normal" road crank than on a compact crank because of the slightly greater vertical distance between the chainrings on a compact crank which the chain must travel before engagment ... AT LEAST YOU CHOSE CAMPAGNOLO SHIFTERS!!

Even if YOU continue to use a cassette with an 11t, there will be someone who has a 52t-or-53t chainring + a cassette with an 11t cog ... and then, where will you be on that long descent?!?

I'll tell you -- you'll probably feel as though you are trying to chase down a 'team' that is riding a Tandem because the other rider who has a 52t-or-53t chainring + 11t will probably be able to slowly pull away from you no matter how fast you pedal.

 

[teamgomez]

Ahh screw it. I'm strapping on JATO packs and calling it even across the board (also inventing an 'off' switch so I don't become the next piece of debris in low orbit).

Great fodder for coffee conversation after the ride- appreciate the thoughts.

 

[PeterF]

I'd get the 12-25 cassette. There really isn't a need very often at all for an 11 tooth.

+1 and I always hate giving up the nice smooth shifts when you're missing one of those cogs in the middle of the range. I bought an 11/25 but now wish I went with the 12. I'm never in the 11t.

 

[PeterF]

I remember watching a little segment during a race by Chris Carmichael and how to win a sprint finish. One of the things that jumped out was how he said not to use too big a gear, since it is very hard to accelerate when you're pushing too big a gear. I honestly think most of the townlines I ever take are in a 53/13 or 53/14.

 

[franky-D]

I just switched cassette from a 11/25 to a 12/25 and I noticed the 12/25/ shifts are smoother and it gives me two more every ride usable gears. Very rarley used 11 inch gear. I ride a compact 50/36 I'd go with the 12/25

 

[alienator]

I just switched cassette from a 11/25 to a 12/25 and I noticed the 12/25/ shifts are smoother and it gives me two more every ride usable gears. Very rarley used 11 inch gear. I ride a compact 50/36 I'd go with the 12/25

While strictly not true, it's true fairly often that there's no such thing as a free lunch. Any time you take a given gear range over say 10 gears and increase that range without increasing the number of gears, you're going to give up something. All companies don't open up a gear range the same way. Sometimes if you shop around you can find a cassette that loses a gear in a place you don't care so much about. No matter what you have to think realistically about your needs.

 

[sogood]

I just switched cassette from a 11/25 to a 12/25 and I noticed the 12/25/ shifts are smoother and it gives me two more every ride usable gears. Very rarley used 11 inch gear. I ride a compact 50/36 I'd go with the 12/25

A new cassette will shift better than a worn cassette.

Given OP's concern with cost, then a Chorus or Centaur cassette would not break the bank and will be more durable than the Record Ti cogs. At the end of the day, it's a personal decision and the only way to know is to try. Buy a cheaper 11-25 and ride it for a while and see if it suit the terrain being used.

Personally, I like my 11-25 and I am comparing two bikes with the same Campy CT set up, one 11-25 and the other 12-25. I need that 11 for a particular section of our club's training ride and I don't really notice the missing 16.