50/34 to 52/36 Chainring swap
 

Anyone gone from 50/34 to 52/36: Which do you prefer? I'm riding a 50/34 now but am considering moving up in size just for increased speed on flats. Anyone who did this regret it once they hit some steep climbs?

For something a bit different.. try the Wickwerks set.. and potential best of both worlds?

https://wickwerks.com/products/road-...ra-wide-53-34/

How fast are you going on flats?

It's not just about top end speed but also maybe about how fast you can continue to go before you need to switch to the small ring. Or how fast he wants to be able to cruise at in the small ring without having to switch up to the big ring?

1.3 mph difference at 90 rpm between 52 and 50 large ring with an 11 tooth cog.

Bragging rights. Let's face it, a 52 or 53 tooth front sprocket just looks much cooler than a 48 or a 50. Tells the world you like going fast. :giver:

I guess it depends. I guess I can cruise between 19-22 mph.

I just did, I’m actually quicker up longer climbs (less bailout I guess). I like it because I can spend more time on the small ring.

A lot of it depends on your cassette,
i ran 50/34 with 11-32 and that was annoying (gaps in gears seemed wide)
Ran 50/34 with 11-28 and that was much better
Ran 52/36 with 11-30 and that seems about the same as the 52/36 11-28

I'd mess around with the cassette before messing with the chainrings

50x11 gearing should be good for 35mph. If you are spinning out at less than that, you need more work on the motor. Gearing isn't the problem here.

If you aren't already spending a lot of your time in the 11 and 12 tooth cog with the 50 front, then a bigger chain ring isn't really going to help you get faster.

I’m a big fan of 50/36, in the finest #41ier tradition of suggesting yet another option.

I went from 34/50 to 36/52 (and from 11-32 to 11-30) when I switched my Defy for my current TCR and there is a noticeable difference when climbing hills, that's for sure. I don't regret the move, but clearly I had to adapt. My previous bike's ''1st'' (easiest) gear feels like my second or third gear on my current bike.

If you feel like you could benefit from increased top speed and don't mind the increased muscular effort to run that setup, why not?

I'm really, really curious here. How are you going to get increased speed on flats by going from 50/34 to 52/36? Are you already going faster than 34 o 35 mph on flats?

Almost all I ride outside of group rides is flats, and I just went the exact opposite way and installed a 46t chainring in place of my 50t. Yesterday I hit a speed of 22 mph coming out of a slight dip in the road that I powered through and looked down to see I was still only in my 4th or so smallest cog. Oh, and I use a 12-25t cassette, so I already "limit" my speed by not having an 11t cog. That speed of 22mph with no tailwind is already faster than I can cruise at outside of a paceline. Literally the only way in which my tallest gearing of 46t/12t will limit my speed is A) if I'm riding with a 25+mph tailwind, or B) I'm descending the occasional hill during a group ride and am not satisfied with my "spin out" speed of only 30-32mph.

I suppose if you're a "masher" and you'll only pedal up to 75rpm or so you'll need 2-3 smaller cogs than me, but even at 75 rpm a 46/12 will have a person at just over 23mph, and at 90 rpm it's 27.7 mph, and it only takes a little over 95rpm to break 30mph with that gear ratio.

Anyhow, I'm not trying to talk you out of it. I realize people are different and do things differently, and the whole mashing/spinning thing will make a difference in what gearings people need, but I'm still genuinely curious: how fast are you riding, and how fast do you think you'll ride on flats moving from a 50t to 52?

I like having a 52 or 53 on downhills, since I always pedal. May not be much faster, but it "feels" faster. On the flats, it's not so big a deal.

+1

50x12 is fine for up to almost 40mph on descents, and I never get close to that on the flats.

Bigger gears won't help the OP get more speed on the flats.

No guessing needed... you can calculate how fast you can go in each gear (minus some real world variances like wind, hills, etc.)...

BikeCalc.com - Bicycle Gear Speed Chart

50/34 for me. Can't think of any advantage a 52/36 would give me but I can think of a few negatives. And yes, I have ridden both combinations.

I have a 50/34 set of rings for my new bike. It came with a 52/39 pair which I actually like a whole lot better than the Compact set, so I'm riding the 52/39. 11-34 cassette. I have no problem climbing or on the flats, into a headwind, winding it out on descents, etc. Everyone likes different things for different reasons.

Save your money and learn to pedal at a higher cadence. More speed, same gears, no money!

Thanks for the input. I asking because I ever never ridden on bigger chainrings. Appreciate the insight!

No worries. If you don't mind the suggestion, try looking down and keeping mental notes of what gears you actually use. If you're using an 11-whatever cassette and a 50/34 crankset and are cruising less than 20mph on the flats you're almost certainly using only half or just over half of the gears in your cassette almost all of the time, unless you've got thighs like oak trees and mash at a very low cadence. You may think you have an 11-speed, but in reality in these conditions you've got more like a 6-speed bike. Going from 50/34 -> 52/39 just makes this worse, because it doesn't change how hard you can push or how fast a cadence you can spin, it only pushes you further to the left on your cassette for any given speed, limiting even more how many cogs on your cassette you're actually using. The 52/39 makes slightly less use of the spread of gears available to you on the cassette than the 50/34 does. The 52/39 would increase your potential max speed, but in a speed range far, far above the range you said you're usually riding.

If you don't mind I'll explain why I installed the 46t chainring on my bike earlier this week, merely as an illustration of the consequences and the considerations involved. My own considerations may or may not apply to you, and I offer them only to show the kinds of things that are affected by a gearing change like this. An expensive alternative to thinking about what a gearing change would actually do is to just buy the new chainrings and install them and see what happens. That's "a way" to learn, and it's your money and your bike, so none of us can tell you what you want or need to do. :thumb:

First, compare gear ratios in the higher end of the gears that you typically might use on your cassette.
50/15t = 3.333 46/14t = 3.286
50/16t = 3.125 46/15t = 3.067
50/17t = 2.941 46/16t = 2.875
50/18t = 2.778 46/17t = 2.706

Notice that you get very close to the same ratios as the 50t chainring using the 46t chainring but shifted over one cog smaller on the cassette? A good first approximation is that going from 50t -> 46t up front shifts you to the right approximately one cog in the rear for a given speed and cadence. The error in that first approximation is erased by what you actually do when riding, which is to slightly adjust the speeds at which you shift in order to get the cadence that you want. That's one cog more of your cassette that you're actually using. Another way of thinking about it is that you have one lower gear accessible using your large chainring with the 46t than with the 50t, at the cost of having one less higher gear accessible, but that's a gearing you're not using anyway, so it's no loss at all.

In my case the move from 50t to 46t up front eliminated the only front derailleur shift on my usual rides because that one lower gear made it so I'm no longer front-shifting for my acceleration out of an intersection. Eliminating a front shift during acceleration is quite nice. This was made possible because now instead of only using about 6 of the 11 cogs on my cassette for nearly all of my rides I'm now using 7 of 11. By shifting one cog over to the right I'm also keeping my chainline closer to straight throughout my speed range using the 46t vs. the 50t. A straighter chainline saves some small and probably unnoticeable amount of power, and also saves some amount of wear (cross-chaining wears a chain and both your chainring and cog teeth out faster than riding with a straight chainline).

In my case, I was already technically limiting my top speed by using a 12-25t cassette instead of the 11-32t cassette that came on the bike. Big loss there: it dropped me from a max speed at my spin-out cadence of maybe 34mph all the way down to a max speed of maybe 32mph. When I ride on the flat my all-out sprint speed is around 27-28mph, so eliminating the 11t cog on my cassette didn't cost me anything at all in terms of top speed on the flats. On those occasional rides with a little climbing and descending I'm content, when I reach 32mph or so, to just assume the most aero tuck I can and ride it out. My threshold cruise speed on flat roads is around 20mph. At my threshold cruise cadence of 92-95rpm using the 46t chainring that puts me about in the 17t cog. Using the 50t chainring that's about the 18t cog. Even starting at 12t instead of 11t like the typical 11-speed cassette at my threshold cruise (ie: about as fast as I can go for extended time) I've still got like 5 cogs left.

In my ride this afternoon I sprinted briefly over a short segment and hit 28.4mph at a cadence of something like 106rpm. I didn't notice what gear I was in, but the calculator says probably the 14t. The "so what?" here is this: even limiting my highest gear in the cassette to 12t, and with a 46t chainring up front, on flat roads I do not run out of gears, period, even at my all-out 20-second sprint speed, and there's still another couple of cogs left over for if I manage to somehow improve my fitness phenominally and increase my sprint by 2-5 more mph.

The only practical loss I will suffer using a 46t chainring will be the top speed I can achieve on a descending road that's not steep enough for gravity to get me faster than around 32mph or so, but steep enough that with an 11t cog or a 50t chainring I could still add a little speed. This happens rarely for me, and in those rare occasions I'm perfectly content to just hit my top speed and ride it out. I'm not racing anybody, so 32mph vs. 34mph down certain descents makes really no difference to me at all. By contrast, the benefits I get from a 46t chainring and max 12t cog in the rear are things I get to enjoy on nearly every single ride, and throughout each ride. I get a larger range in my cassette where my shifts are all 1t shifts, which keep the disruption to my cadence during acceleration to a minimum. I get a low-enough usable gear in my cassette that I have no need for any front derailleur shifts on flat roads. I get a straighter chainline.

Anyhow, if you're still reading this, these are the kinds of considerations that come into play when changing gearings. My considerations may or may not be relevant to you, but since you said you cruise mostly on flat roads, and with a very similar speed range to mine, I'd suspect they probably are also relevant to you. What would make them possibly less relevant would be if your cruising cadence is much less, or much more than mine. That would simply shift which cogs you actually use on your cassette either to the left or to the right of the ones I mainly use by 1 or 2 cogs, and the rest of the analysis would be about the same.

Btw, here's an example of a useful bike gearing calculator. There are others that I've used, this is just the one I pulled up while thinking about this post. I like Sheldon Brown's calculator too.

North Central Texas has lots of roller coaster terrain but few serious climbs. When I was younger a 52/42 chainring and 13-24 freewheel was good enough. But I've had to compromise the past year or so. For the occasional slog up a 1-2% grade into a headwind I'll use the 38T or 39T chainring and 28T rear cog. And that's for a fairly heavy steel frame bike. With the lighter carbon bike I'm still okay with 52/42 and a 28T largest cog in the back.

I tried a 50T big ring for awhile but with only a 13T small cog in the back I'd occasionally spin out on downhills and a few flats with a tailwind. So I switched back to a 52T big ring.

If I did try a 50/34 chainring I'd probably consider a closely spaced 10 or 11 speed cassette, not 11-32 or more -- maybe a 12-15 or 12-28, if there is such a thing. For a lightweight road bike a 34T chainring and 32T rear cog is overkill for pretty much any climbs we have in this part of Texas, even with a headwind. A closely spaced cassette with 28T big cog would be less tiring over distance on most of our terrain where just a tiny shift in gear inches/ratio can help keep up the momentum without bogging down or spinning inefficiently. With my old steel bike and 7-speed 13-28 freewheel, some shifts are inefficient. It was fine when I could still churn 13-24 comfortably -- better gear spacing in the middle cogs where I spend most of my time.

I like and use a 30T small ring and 32T cog on my hybrid but that bike weighs 30 lbs and I'm often hauling stuff on the back, so, sure, a granny gear is great.

If I ever finish a third road bike project with 10-speed cassette I'll probably keep the 11-25 the bike came with and try the original 52/39 for awhile. I suspect I might need to drop down to a smaller chainring but I'll need to ride the bike awhile -- it should be much lighter so maybe I won't need to swap chainrings.

A general couple rules of thumb to think about if you make the swap. Not exact but it'll give you an idea

For your likely typical given cadence:
The 52 will go about 1mph faster, whether you're in the 11 cog or a bit less than this (..7mph) if you're say in a large cog like a 23/25.
The 36 will go about .5mph faster, in a big cog (eg 28), or 1mph faster in a small cog (eg 12 or 13)

The downside is hills and if you struggle now with any of your hills using the 34, then going to a 36 is obviously going to be a bit of a detriment.

My CAAD 12 came with 52/36. I rode it for about 1,000 mi. and went back to 50/34. I just found that I was working too hard for no benefit. Thus, I was slower. Now that I have the 50/34 it's much more fun for me.