banerjek

One gearing combo that keeps showing up on this forums is an 11-23 mated with a 50/34.

I like compacts, but you wind up with no gear selection right in the middle of the range unless you have 15 teeth or so between the largest and the smallest cogs. What's the point of a compact with a narrow cassette except for a race or when you absolutely know you won't need your small ring? There's practically no overlap and if this combo really is useful, it seems like a standard double would be a better way to go.

gregf83 

I'm about to switch to a compact SRM with a 12-23. Most of my riding will be in the big ring in the middle of the cassette. The hills that I encounter most often are in the 2-5 min range so I can either stay in the big ring and go hard or switch to the small ring and spin up. For longer hills, 40+min, I will have more options than I currently have with a 39 little ring.

I don't see a problem.

canam73

I have TT bike that I often set that way. Typically TTs don't have much for climbing or descents so for flats and rollers I can do the whole thing in the 50 and have very close spaced gears. I considered a 21t top but then I remind myself that I don't actually care enough about the TT in triathlons to warrant a specialty cassette as I run the 23t on my 53/39, too.

AMFJ

because I don't want to swap out cranks ($$$$$) when I go do mountains, but I don't need huge spacing during races or even during normal weekly rides.

Mostly, I've never felt held back by "only" having a 50 upfront. I've never been in the the 11 and wished I had the 53 up front--during a race, hammerfest ride, solo ride, etc.

bikerjp

Actually, for rides with no really steep climbs I find this to be a pretty nice setup. I set up my caad with an 11-23 and at 90rpm can ride from about 17-33 mph (I don't ride at over 25mph unless I'm going down a hill) on the big ring using the 21-11 cogs which doesn't cause any real cross-chaining. That's a pretty good range of speed for me and I don't drop out of the big ring unless I hit a moderate hill. On the 34, the 11-14 basically overlap the upper cogs with the 50 so aren't very useful but also that does start to cause cross-chaining issues for me - especially the bottom 2. However, the 15-23 work great in that 16 down to about 10 mph range maintaining a comfortable 90ish rpm. If I expect I'll be riding slower than 10mph (i.e. steep or sustained hills) then this isn't usually the bike I take but I have.

TLTD version: from 10-33 mph the 34/50 and 11-23 combo works pretty well. Not so much for steep climbs.

EDIT: I will say that an 11-28 is a much nicer all around setup, but on flatter, faster rides I like the 11-23.

AdelaaR

This.
Only difference is I do it in the 53.
Closely spaced gears is the key here.

PartsMan

That is the idea of a compact setup. Less overlap is a better use of the weight.

canam73

I wonder who is more awesome, Adelaaaaar or Hgggg?

cyclezen

Been ridin my Marin Trevisio a lot recently, in an effort to get back some lost fitness and power. I use the bike for weekday training on my rolling section rides. It's slightly weighty steel, rolls well on the flatter sections and is a good workout when punchin up the rollers.
It has a 50/34, and the wheel which is most often on it is 13/14/15/16/17/18/19/21/23...
on some rides which incorporate 800 to 1000 ft vertical climbs, I'll swap to a wheel with a 13/14/15/16/17/19/21/24/27...

only compact left in the quiver - all else has been changed back to either triples or 53/39 stds...

I would not buy a compact again, if I had the option. When this crankset goes, I have a std ready to replace it...

banerjek

I totally get that if you know you're not going to use the bottom ring. Or if you swap cassettes. But it looks like a lot of people ride them for all around riding which would put people constantly at the bottom of their big ring or the top of the little ring -- i.e. they have poor gear selection right around their cruising speed.

Likewise, on hills you tend to use the bottom gears going up and the top gears going down. Again, that calls for a wider setup.

Dunbar

I'm thinking about running an 11-23 or 12-25 cassette (can't decide) with a 50/34 on my next bike. I would swap on a spare rear wheel with a 12-28 or 12-32 cassette for climbs. I often find myself wishing I had an in-between gear with my current 9sp 11-28 cassette in the flats which is why a tightly spaced cassette has some appeal.

banerjek

Note that the only difference between a 12-25 and a 12-27 are the bottom two cogs.

If you're using the 25, you probably want a 27, so you should be debating between the 11-23 and 12-27 (or 11-26). Frankly, if you put on the spare wheel for anything involving climbs, you might want to consider a 12-23. It has even less overlap, but if you don't need it, you gain the 18 which is useful.

cyclezen

some overlap is not a bad thing.
on a compact it seems that one has to double shift at the most in-opportune times, like when you're making a transition to some uphill work. Just when you want to keep up momentum, you have to shift the front 'down', the rear back 'up' and during all that, keep a steady cadence to retain any momentum...
this is prolly not a bad thing if speed is not a consideration... but if you're trying to keep hold of a high tempo groupetto... or punch up a short climb/roller - it's evil.
a 53(52) x39 (which includes triples...) just doesn;t seem to have those flat spots - because of overlap....

riding compacts reminds of driving my old VW bug, east to west, over the appalachians...

bikerjp

Why can't you use the bottom ring?

banerjek

You can use it, but if you have practically no overlap your gear selection would suck if you actually intended to use it unless you were on rollers in which case you'd be alternating between the big cogs with the 34 climbing and the small cogs and the 50 descending.

If your cruising speed is just shy of 20mph as is the case with a lot of people, just a little wind puts you in a position where your big ring is too big and the small ring is too small.

bikerjp

Actually, at around 20mph the 50 has you closer to the middle of your cassette (16, 17 and 19 cogs) than a 53 (mainly your 19 and 21 cogs). There is slightly less overlap. When your speed drops to around 15 mph the 34 makes sense. You can also ride in that 16-19mph range quite comfortably on the 19 and 21 cogs and on a compact it doesn't cross chain badly.

I think for average riders the compact makes a lot of sense. The 11-23 only if you are on flat and rolling terrain and less ideal on climbing rides. I agree that an 11-23 is not a good all around cassette. That's why I have two bikes. 11-23 for flatter, faster rides and 11-28 for rides with varied terrain.

34-50


39-53

merlinextraligh

That's my current setup. Basically flat terrain I don't need any lower gear (in fact I could use an 11-21).

With the compact, I can put on an 11-28 for mountain rides, and have a very low gear, and the 50-11 is big enough gear that I'm not giving anything up.

So everyday I've got tig spacing, and then the flexibility for low gars for trips to the mountains. Best of both worlds.

generalkdi

As I live in a quite mountainous area, 11-23 isn't an option for me. It's hard enough with my Compact + 12-27 cassette...

ericm979

Thats the problem. Especially on rolling terrain. You'll be shifting many cogs in the back each time you shift chainrings. That's why I think that a 50/34 or 52/36 works better with a wider range cassette like 1x-25 or larger. If you don't need a gear lower than 34x23 then narrower range chainrings like 53/39 or 52/38, and an 1x-25 or -27 would be a better idea.

jsigone

I've been running compacts w/ 11-23 for the past few yrs and even on the long 5000ft climbs, just keep the leg speed up and it's not much of a problem.

ericm979

Bikerjp, your chart's messed up- it shows a higher speed in 34x11 than in 39x11, and slightly lower speed in 39x23 than 34x23.

When you look at ranges you need to take the unusable and cross chain cogs out. Most 50/34 setups can't use the smallest cog at all and many can't use the next to smallest as the chain rubs on the 50t ring. And you want to stay out of the 50x23 and 34x11.

bikerjp

It's from this site.

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

Not sure why it squished it like that. Here's another try.

39-53


Actually, both were messed up. I've updated the images in the post above.

RollCNY

Not one has chimed in with this, but after having compacts, I prefer a 50/36. The 14 tooth drop is much more pleasant shifting than the 16 tooth of a normal compact.

But honestly, after riding around with a 50/36 and 12-25 for months, my main bike has a single 46 tooth front ring, and a 12-25 for most rides, and an 11-26 for hills. I have found front shifting to be overrated.

Psimet2001 

You don't need the small ring at all around here. You can seriously go months without ever shifting your front. Compact or Full sized double. I run a 11-25 so that I never have to shift the front in reality, but most riders can easily get away with a 11-23. These are on full sized. Compact - you are much better off with a 11-23 around here.

I blame the glaciers.

Literally - you never need the small ring unless you hit one of our few super grades of 15-20% which have this nasty habit of popping up every now and then and last for a WHOLE BLOCK before we go back to flat.

Ultraslide

I run a 50/36 11x23 to solve some of the overlap issues. The shifting seems to make more sense than 50/34, where you are cross chained all the time.
For long climbs I move to an 11x28 and maybe the 34 up front if I need to keep my HR down.