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12-25 or 12-27 cassette to run with a triple ?(25 posts)

12-25 or 12-27 cassette to run with a triple ?scopestuff2
Sep 11, 2003 7:21 PM
Tomorrow at noon I'm 'upgrading' my ultegra 9-spd double to a triple. Front chain rings are 52/42/30. Trying to decide whether to run a 12-25 or 12-27 on the rear.

On paper the 12-25 is tighter, but considering how I ride my current double the 42/27 might come in handy every now and then and save me from dropping to the small ring. I can look at paper gear charts for ages and never decide. so I thought I'd ask opinions from people here.

How do you ride your triple ? What cassette spread would you go with ? When I look at a gear chart it seems that I should only be in the middle chainring for just a few middle-cog combinations and the rest should be on either the large or small ring. However, what I've read online is that people tend to spend the vast majority of their time on the middle ring.

Thoughts, suggestions, opinions, please !

Thank you in advance !
12-21 with a tripleKen K
Sep 11, 2003 7:39 PM
I run a 12-21 cassette with a 52/42/30 triple up front. I like having the tight gear spacing on the back but the tradeoff, as you mention, is more frequent shifting of the front chainrings.
here's how I see itDrone 5200
Sep 11, 2003 7:45 PM
I've got the Ultegra 52/42/30 with a 12-25. My house is on the side of a mountain, so I have two basic choices when I ride from home: (1) stay around the house and do some climbs, or (2) drop to the valley floor and ride on the flats. But when I go down I always have a good hill to climb to get back home.

I usually go down to the valley floor and cruize for a while. That means I'm in the big ring most of the time. Usually on the 17, 15, 14 or 13 cogs as needed. I like the closer spread of the 12-25 and wish I had that 10-speed #16. I use the middle a when I'm on a recovery ride.

Then it's back home up the hill. I have found that 30/25 is low enough for any of the hills around here. For me, I wouldn't trade the middle gear for a 27.

When I stick close to home and concentrate on climbing, I drop to the small ring up front and stay there. Usually in the 25, 23 or 21 cogs. I really like my triple front ring.
Why did you upgrade?NC_Jim
Sep 11, 2003 8:49 PM
Because it's easier to climb with a triple. A 12-27 makes it even more so.
Why did you upgrade?scopestuff2
Sep 11, 2003 10:19 PM
Thank you's to everyone for the quick replies. I haven't heard anyone say that the triple shifts horrible, or to stay away from it ... so that is good news.

To Answer NC_Jim's question: I'm going to the triple because I live in Northern California. Virtually any long ride is going to include a fair amount of climbing. Typical rides seem to have climbs around 2,000 feet and up to 3,800. I'm a nubie and find that I'm a bit hesitant to go on some of the longer rides for fear that with the double I just won't have the legs if a ride brings a long/hard climb near the end of a long ride. I'm fine with the double for 30-40 miles and 2,000 foot climbs with even moderate+ grades. But, if I hit a hill like that at mile 60 or so ... I concerned that I'll take it in the knees rather the legs.

Also, I have set a goal to climb Mount Diablo. I've heard that it's pretty challenging at about 3800 feet in 10 miles or so (forget the exact distance) with the last 4 or so miles being pretty challenging. I know I have the endurance. But, I'm not sure that I could push a 39/25 without straining my knees (which give me some trouble already from running related injuries).

So ... my desire for the triple is really two fold:
1) To have the proverbial bail-out gear (that I've not yet really needed).
2) To climb mount diablo and suffer only muscle pain, rather than joint pain.

All of this is based on fear rather than experience. But, I don't want to find out the hard way and have the experience of blown-out knees.

Still interested in more feedback. The replies so far have been very interesting. I'm a nubie (6 weeks of riding) and learn more with every reply. Thank you all in advance !
Why did you upgrade?wolfereeno
Sep 11, 2003 11:35 PM
I use my 30-27 every now and then. Maybe I'm a wimp but I seem to pass a fair number of people and can keep up with guys that seem younger and fitter than me. I do like to spin fast at a 80-95 cadence on hills when I can.

I've never ridden a cassette like a 12-21 and imagine it shifts pretty smooth but I've got no complaints and don't think I could climb the same kind of hills with only a 21 in the back.
Why did you upgrade?JAishima
Sep 12, 2003 8:57 AM
I have a triple on my bike (12-25) and the top of Diablo makes me wonder if I should be using a 27! If you have spare wheels, you can always put the 12-27 on when you're climbing Diablo, and a 12-25 or something for everything else.

Unless you're really strong, you may be walking the top, anyways. Go for the 27 and see what happens!
Can you get a 39 in the middle like Campy? Then 12-25. nmSpunout
Sep 12, 2003 3:58 AM
better stuck with it than caught without itJS Haiku Shop
Sep 12, 2003 5:01 AM
then again, my vote is to get both cassettes, a cassette tool, a chain whip, and a large crescent wrench.

my triple-equipped bike (ultegra, 52/42/30) has an xt rear derailleur and 11-32 cassette. i have never wished for "tighter" gearing on flat ground, or "higher" on downhills. i've ridden a variety of cassettes, from 12-25 to 12-27 to recently 11-21 (thanks Baneser) on a hilly double century, and still am happy with the ultegra bike's setup. rides like the 6-gap century and other steep endeavors are much more "enjoyable" with low gearing (i'm a big boy).

i'd rather have it and not use it very often, than need it and not have it, limiting my ride experience.

get the 12-27.
13-25 and 12-27 (nm)Chen2
Sep 12, 2003 6:18 AM
I'd go 12-27 depending on where you livepmf1
Sep 12, 2003 6:30 AM
If you live somewhere flat, then a 12-25 or even 12-23 would be OK.

The big problem with the Ultegra triple is the 42 inner ring. There is no 39 ring for it. So on a hill, you're either stuck grinding up in the 42, or spinning like crazy in the 30. For that reason, I favor the Dura Ace triple what has a 39 tooth ring. I put one on my wife's bike and she really likes it over the Ultegra triple that was on there before.

If you're worried about 19 extra grams (or whatever it is) weight difference in the two cassettes, then you shouldn't be using a triple in the first place.
I run both andcyclopathic
Sep 12, 2003 7:02 AM
12-27 is better choice IMHO. 12-25 and 12-27 have the same first 7 cogs and last 2 are bail out. 24/27 is better bail out then 23/25, at least for me.

Typically you use triples as doubles with granny as back up for tired legs on steep hills. 42/27 has the same ratio as 39/25 and 42/25 as 39/23. On short (century+) or flattish rides I won't use granny at all.
did i read you post before saying you weigh <145#? nmJS Haiku Shop
Sep 12, 2003 8:40 AM
did i read you post before saying you weigh <145#? nmscopestuff2
Sep 12, 2003 9:13 AM
Wow ... you've got a good memory.

Yes ... 5'8" and I typically weigh about 130 +/- a pound or so.
are you asking me?cyclopathic
Sep 12, 2003 9:39 AM
I am normally 146-150lbs, but after PBP I was down to 136. It is up to 142 now and I can climb better; I'll maintain it at 140-142 level.
yup...JS Haiku Shop
Sep 12, 2003 9:53 AM
your gearing recommendations usually sound as though they were issued by a lightweight/climber, and i know you're a distance junkie, so that compounds them. i have 60 pounds on you, and appreciate a "granny" on "short rides" (~100 miles) with "some" climbing (11,000 feet).

I wish i weighed 140 on "heavy" days, but then i'd look like a 6-foot stick figure or one of those guys on "caution: pedestrian" road signs.

I wishcyclopathic
Sep 12, 2003 10:51 AM
I have bad knees so I can't really push high gear. However, I can stand on pedals for the whole climb and we don't have that many steep hills around here, not like Fingerlakes. Most climbs in MD/NoVA/PA are below 10% avg, usually in 5-8% range if long 2-6mi, with some kicks into mid teens; a few steep short suckers. Yes, there're some tough climbs to Blue Ridge like Wintergreen but I do not ride them that often, and that's what I have granny for :)

Second I do not race nor do any interval training plus I have asthma so my LT power is mediocre at best. I have friends who are in 180-220lbs range who outclimb me. Plus weight isn't everyting I climb much better after I regained 6lbs.

I wouldn't reccomend you to loose 60lbs, you won't have any power left maybe 20 or so, if you have that much fat to loose. At 136 I drag my feet; it felt like I am getting sick all the time and LA on 'zine cover looked pretty fat comparing to me :)
I run a 12-27vindicator
Sep 12, 2003 7:57 AM
I have the same triple crank as you and when I was a noob (not that I'm Eddy Merckx now) I bailed on the 12-23 and replaced it with a 12-27. I haven't been tempted to switch it back yet, except that when/if I get a second set of wheels for racing I'll probably put the 23 on it (I'm too cheap to get a second bike just for racing and run just a double on it).

I do miss the 16 cog at times, but you can't get it with the 12-25 either (IIRC). At the large cog end of the spectrum, I don't miss any of the intermediate cogs that I skip working my way up to 27.

As for how I ride it, like you say I spend the majority of my time in the middle ring. Big ring for descents, fast flat sections, and races. Essentially, I use the whole cog with the middle ring (trimming as needed of course) and can handle most climbs without needing to go beyond the 42-27. Except for races, I only use the big ring with about the first 5 cogs or so and the little ring with the last 5 or so. Seems to work well with a minimum of chainring shifts.

Last fall, I used the little ring a lot more but my climbing power has improved over time. Still, as J said, I like having the 30-27 and the 42-27 when I need them. Nothing like still spinning at 85-90 rpm while your buddies are crunching at 55-60 doing the same speed!
...and...JS Haiku Shop
Sep 12, 2003 8:42 AM
nothing like crunching the 30 ring at 55-60 rpm while your buddies are walking a 17% grade in funny italian shoes and pushing the bikes.
Sep 12, 2003 10:24 AM
nothing like sitting, spinning and chatting in 30T ring up 26% grade while you buddes twist handlebars in 39/23 and give you "I'll kill you when I catch my breath" look.
Different view...KEN2
Sep 12, 2003 8:58 AM
I run a 12-23 with the Ultegra triple 53/42/30. The reason I prefer the Ultegra over the DA triple (53/39/30) is that the gearing on the DA always seem like an afterthought, i.e. the 30 is "grafted" onto the basic roadie 53/39 double. With the Ultegra 53/42 you can do one double shift to get to the next gear ratio--for example, going from the middle ring to the large ring in front, you just shift the rear one cog larger. With the 53/39 it takes a two cog shift to get you to the next ratio step.

And the reason I use the 12-23 cassette is I want tight ratios for most riding--the 30 ring is a bailout for climbing for me, but since I ride in paceline groups etc. I don't want widely-spaced ratios. YMMV
Get the 12-27LC
Sep 12, 2003 9:23 AM
If you need a triple then you might as well go for the 12-27 so you have plenty of bail out gears. If that is your only bike then I would also have a 12-23 handy so you gain the 16 cog. The 12-25 does not have a 16, so it is not really all that useful to me and using the 24 in the 12-27 is close enough to the 23 and the 25 that it is not worth even shifting since your only changing very little when at those slow speeds.
You plan on climbing walls?KG 361
Sep 12, 2003 9:59 AM
Either seems a bit of an over-kill to me. I rode some really steep, long climbs in France on a bike equipped w/ a triple and it had a 23 as the largest cog. Didn't use it much, and that was on only the steepest stuff.
define 'steepest', and...after how many saddle miles? nmJS Haiku Shop
Sep 12, 2003 10:06 AM
10-12% in sections, 8-10% mostly for approx 5-6 miles.nmKG 361
Sep 12, 2003 2:58 PM