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Why do you use a 12(23 posts)

Why do you use a 12Stanley
Sep 26, 2001 6:51 PM
I've been reading the comments on gearing and wonder why you people use a 12. I start with a 13. At present I have a 13-23 9spd, but having moved am going to get a 13-25. Now I'm only 30 and I race quite well. The thing is a 53x13 at 120 rpm (which shouldn't be difficult to spin at) is going to give you 60 kmh. I think this big gear thing is way over done. Sure I sometimes feel like I could use a bigger gear but I just wind the gear out if I need to (i can hit 197 rpm on my rollers). Way I see it, starting with a 13 means that you will have a closer set of gears across the range where you a more likely to use them. Anyway, I would be interested to find out why people go for a 12 particularly those who don't race or are vets with tyred knees.
re: Why do you use a 12GregJ
Sep 26, 2001 7:35 PM
I can turn a 12 with a REALLY strong tailwind but that kind of wind is very rare. I do live where it is mountainous and I use it on the decsents that aren't too technical and are smooth. Although I should say I rode for years with a 13, when I got more gears (8-speed to 10-speed), I did start to use the 12. I don't really go much faster, but it is nice to slow down the cadence a bit when flying downhill. BTW, did you see the stage of the Vuelta today? The USPS team split the bunch in a crosswind and then HAMMERED with a tailwind all the way to the finish to move their guys Heras and Leipheimer up the GC. They were riding so fast on a flat road absolutely spun out in their highest gear. I'll bet they were all wishing they had a 10!!
Me?Dog
Sep 26, 2001 7:36 PM
I use a 55/11 gear, and do get it spun out at times. In the mountains and the desert, you can find very long descents or very high tailwinds, and cruise at 40 mph for quite a while. Having the tall gears allows you to go faster with less fatigue (than you would at 197 rpms, for example). Not for everyone or every circumstance, but there are justified applications for them.

Doug
Why I you use a 12Atombomber
Sep 26, 2001 8:37 PM
I've tried to pedal at higher cadence, but my physiology seems to want me to crank out a steady 95ish. There have been quite a few instances where I'd be plodding along, gearing down and down until I was in the 12 for many a kilometer. I am built for flats. When the road goes up, I start to really slow down. My riding friends call me Diesel for a reason.
I use an 11nuke
Sep 27, 2001 10:02 AM
I agree with AtomBomber (hey...cool name too! :-) I'm a clydesdale cyclist and I've noticed that there is a significantly higher % of clydesdales that LIKE to run at a lower than race cadence but CAN grind out big gear ratios.

I do some races and even in there, in cruise mode, I seem to naturally like a lower cadence in a big gear than the opposite.

I've heard it said that mountain bike gearing dropped from the previous standard to "compact gears" (i.e. smaller gearing because basically, most people don't have the leg strength to enjoy grinding out that higher gear ratio. So...for those of us who DO have the powerful legs to do it, I say, do what works for you. There is NEVER only one answer!
With my 48T big ring the 12 works great. nmMB1
Sep 27, 2001 5:25 AM
re: Why do you use a 12Chen2
Sep 27, 2001 5:59 AM
I think the reason so many people have a cassette that starts with a 12 is because that's the way Shimano makes them. If Shimano would make a D/A or Ultegra 13-27 with a 16 added I'd run right out and buy two. I may try to make my own.
-Al
Because I have slow legsMick
Sep 27, 2001 7:17 AM
I often ride with fast groups. In fast tempo and sprint situations sometimes I need to rest and recover while still rolling along close to 30 mph. In those instances I'll sit on the back of the pack in my 53-13 or even 53-12 and spin very slowly. It works.

Some of us can't spin like Lance. That is, I can't comfortably hold a 95 cadence for more than a couple of minutes. I'm more comfortable between 80 and 90 rpm. At higher speeds, this translates to bigger gears.
Been asking that for years. Nobody listens to ME, eithercory
Sep 27, 2001 7:29 AM
If people had to pass a quad-strength test before they bought a bike with a 53-12, you'd see about one a month. But since that's what the pros use, you can hardly buy a bike without it. I just motor along at 90rpm in my 46-tooth big ring, my pain-free knees singing a happy little tune...
re: Why do I use a 124bykn
Sep 27, 2001 7:50 AM
My 12 gets about as much use as my 27, which is not much. But when I need one of those I'm sure glad I've got them!
That's just the way it ismr_spin
Sep 27, 2001 8:30 AM
Shimano doesn't make cassettes without a 12 as far as I can tell. I certainly can't turn it unless I'm going downhill, so I would gladly sacrifice it for something else.
You can get shimano 13 upStanley
Sep 27, 2001 1:27 PM
My 13-23 is shimano and I can get a 13-25. If you want a 13-27 then you can get marcusio (sp?) sprokets ex the UK in whatever combination you want and it is not too much more expensive than the shimano or campy equivelent. Not sure if they are doing a 10 spd set yet, but I think they do.
197 RPM? good god!Chris Zeller
Sep 27, 2001 8:32 AM
Can you sustain that? I don't ride very fast downhill. Usually chicken out around 35-40 mph and start on the brakes. But I usually do pedal around 80-90 rpm downhill in my 52x11 gear. My legs can't sustain 120 rpm for long. In a higher gear I bet you hardly feel anything, like to feel some resistance on my legs.
197 RPM? good god!Stanley
Sep 27, 2001 1:29 PM
NO, but I can hold about 160
Big Hillsgrzy
Sep 27, 2001 8:38 AM
Out in the Bay Area and Sierras we have some serious grades. Having a 12 lets you punch through 50 mph on the descent with out spinning like a gerbil on a excercise wheel. Have actually used an 11 on occasion. Ultimately it comes down to riding style - the women's RAAM record holder runs a 57/12. Her cadence is quite low but she has the power of a locomotive and thighs to match.
HamsterdanceCliff Oates
Sep 27, 2001 9:02 AM
Using a 53t chainring, a 23mm tire with an approximate 211cm circumference, and 50mph, an 11t cog results in a 132 cadence, 12t -> 144, and a 13t -> 156. All of those cadences are very high for an overwhelming majority of riders, especially if they're already going 50 and hoping to avoid bouncing out of the saddle and into the ground. The prime factors that will get you going 50 mph are gradient, gravity and aerodynamics. Not gearing.
Yeah, but when I go 50...cory
Sep 27, 2001 9:56 AM
...I start thinking, "Everything on this bike was bought as cheap as I could get it, then installed and maintained by ME." That's usually enough to get me back down to 35 or so.
Hamsterdancegrzy
Sep 27, 2001 10:57 AM
Sure you need the pitch, but being able to add a little power bumps up your max. velocity - no doubt about it. Been able to coast up to 52.8 mph - gravity was pulling hard that day.... ;-)
gravityDog
Sep 27, 2001 11:29 AM
"gravity was pulling hard that day" -- maybe you were a little heavier that day :-)
Never in the big ringRod
Sep 27, 2001 10:50 AM
So when I built up my newest bike, I installed a set of 50/39 chainrings and a 13/26 cassette. I can go 30 mph in my top gear, 50*13, but I cannot sustain 30 mph in any gear. When I looked around the bikes in our local club, I noticed that the tall gears are only used by the racers and racer wannabes. The rest of us are just packing along some tall gears that never get used, except on the occasional descent. For me, I can only sustain 30 mph or more on a downhill, and at such speeds it's more effecient to tuck and coast.

The standard 53/39 * 11 or 12/23 cassette on many road bikes isn't all that useful for average cyclists. Great for strong, hard core enthusiasts and racers, but not for average, even serious, but less strong cyclists.
Never in the big ringgrzy
Sep 27, 2001 11:00 AM
Get in a good paceline with strong riders and you can be holding 28 to 30 mph for miles. Nice to be able to take advantage of the draft and turn the legs a tad slower so you have some juice when you're on the nose. YMMV
YMMV is rightRod
Sep 27, 2001 8:25 PM
I've been riding three years and about 6,700 miles. At this point I cannot hold 30 mph in a paceline for long, either. Even in a paceline I'm only good for about 23 mph over several miles. Like I said, a 53*12 is not suited to average cyclists. If you can hold 28-30 mph for more than a couple miles, even in a paceline, you're well above average. Sure, I'd like to ride faster and further, but given the amount of time and distance I ride, I am where I am. If I get faster, you bet; I'll add a larger chainring or a 12 on the cassette. Meanwhile, it makes sense to have a range of gear-inches that are actually suited to my climbing and speed abilities.
Don't use it alot, but I'm glad I have it when I need it!look271
Sep 27, 2001 3:04 PM
Where I live, there are lots of "rollers". It's good to get really flying down one side so you can maintain speed up the other. The 12 lets me do this.