# Why 36/46 and not 34/46?



## CharT (Jun 12, 2015)

After looking at some cyclocross bike gearing, I've been wondering why the popular 2x setup seems to be 36/46 but then compact road setups are 34/50. I'd think that wider gearing for cyclocross with 34/46 would be desirable even with the wide 11-32 cassettes. Anyway, just wondering if someone could enlighten me.


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## Peter P. (Dec 30, 2006)

With all the bouncing around on 'cross courses, dropping a chain is a real possibility. Reducing the difference in chainring sizes aids in shifting and reducing that possibility.


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## pretender (Sep 18, 2007)

There's very little sustained climbing in CX. In situations where you'd need a 34x32 gear, you'd be better off just running. Similarly, there's almost never a situation where you'd spin out a 46x12 gear.

I ran 44/34 x 12-25 last year and it worked well. Generally I'd be shifting the front 0, 2, or 4 times a lap.

Also keep in mind that 50/34 is a real crappy chainring setup. Shifting is clunky, it's just way too wide a gap. Sportif-oriented bikes ought to be sold with 46/36, or 48/36.


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## JCavilia (Sep 12, 2005)

pretender said:


> Also keep in mind that 50/34 is a real crappy chainring setup. Shifting is clunky, it's just way too wide a gap. Sportif-oriented bikes ought to be sold with 46/36, or 48/36.


I agree. The shift pattern with 50/34 is really awkward to my mind; the so called "mid-compact" 52/36 is just as bad. 48/36 is exactly the same ratio between the rings as the old "standard" 52/39, and produces a very neat pattern with most cassettes, IMHO. 46/36 is nearly the same as 53/42, if you remember the old old days.


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## radripperaj (Mar 7, 2015)

I actually changed mine to a 46/34 x11-28. I have an ankle with arthritis problems, but my doctor said i can do cross. He also told me to remember the less I run the longer my ankle will last. Keeping that in mind I went to the smaller 34t, because it was fairly cheap and easy to do. I figure if it helps me dismount just a little later and start riding a little sooner then it was worth it.


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## CharT (Jun 12, 2015)

Using Sheldon Brown's gear calculator, it looks like a 36/46 has pretty much 8 duplicate gear ratios out of 22. Other than the two lowest gears (36x28 and 36x32), the 46 ring pretty much covers all the ratios of the 36 ring.


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## pretender (Sep 18, 2007)

CharT said:


> Using Sheldon Brown's gear calculator, it looks like a 36/46 has pretty much 8 duplicate gear ratios out of 22. Other than the two lowest gears (36x28 and 36x32), the 46 ring pretty much covers all the ratios of the 36 ring.


You _want_ redundancy in a 2x setup. In 2015, the whole point of having a 2x setup is either (1) wider range or (2) more tightly spaced cassette or (3) both.

"Other than the two lowest gears[....]" Right, because why would you care about the two lowest gears?


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## atpjunkie (Mar 23, 2002)

pretender said:


> You _want_ redundancy in a 2x setup. In 2015, the whole point of having a 2x setup is either (1) wider range or (2) more tightly spaced cassette or (3) both.
> 
> "Other than the two lowest gears[....]" Right, because why would you care about the two lowest gears?


my thought as well. Some courses I rarely get out of the big ring, some I rarely get out of the little


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## HEMIjer (Oct 18, 2008)

I guess it all depends on bike use and how competitive you want to be. My CX bike is currently set up as you as state 34/46 with 11-32 10 speed cassette, mix of 105 and ultegra. Cassette and chain are ready for replacement and likely just use a 11-28 since a rarely take the bike in mtns anymore and stronger rider than when I originally thought I would need the 34/32/

Like me, since many use their CX bikes for training and gravel events if your going to use for CX occasionally wider gear ratio might be ok, if you are going to be aiming for podium than yeah I would want close ratio gearing.

I also have a 36 ring a can throw on for 36/46 (never have), have a 38/46 crankset in box likely never go back to, and a 34/50 if I needed for a gravel type event. These are all spare parts form over the years I have hung onto just in case (guess maybe I should unload cheap).

Albeit I am not CX racer, love riding CX courses and a CX bike though!


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## RRRoubaix (Aug 27, 2008)

Actually, I quite like 34/50 for road riding. For reasons I really can't explain my CX setup is 39/46... (It's awful)
I used the CX bike a coupla weeks ago on a "CX/gravel/hillclimbing" ride and was kicking myself for not bringing a bike w/ more reasonable gearing.
I do have a big cassette, 12-28, but that's just trying to make up for the too-large 39t "small ring". Always meant to change it, too late now- new race bike w/ all the crazy Di2 goodness should be here in 2 months.
(Anybody wanna buy a beat up 6-year old Van Dessel w/ crappy gearing? :lol: )


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## Todd_H (Nov 20, 2009)

Do whatever is best for you. Personalize your gearing. Do you like to ride grunty hills instead of running everything? Try the 34t or the 11-32. I've got an 11-32 and it's awesome.


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