What components are required to go 50/34, 52/36, 53/39 ?
 

Hi
I would like to know what components are required to change from one chainset type to another? Compact to mid-compact to standard?
Is is just a matter of changing crankset+chainrings+chain or is there something else?

The context of my question is, if I build a bike with 50/34 and feel I do not like it, can I just exchange the chainset and be done with it? Or do I need to change fron derailleur, shifters etc.
Thanks

Francois

You won't need new shifters or derailleurs. You will need to raise or lower the FD and possibly add or subtract a few links.

Yes, just slide the front derailleur up a little to clear the larger chainring.
With a gear calculator, you can get a better idea of the best gearing for you, before you commit to a chainring size.

~~~~

I like the Mike Sherman Gear Calculator to compare different drivetrains. You can change the tooth counts, tire size, and cadence, and the charts update on the fly.
Here's a link to the 11-28 and 34/50 calculator configuration. The URL has the settings, so you can bookmark those settings for later use.

Here's a typical 11-28 11-speed cassette with 34/50, at typical flat road cadences. The small chainring in red, large ring in black.
https://cimg8.ibsrv.net/gimg/bikefor...8c714ae69e.jpg

The 11-28 with a 39/53. (Note: the chart range is extended to 40mph here.)
The most obvious change is that the 39 chainring can go well past 20 mph before you need to shift to the big ring. But the big ring has some large jumps around 20 mph.
https://cimg0.ibsrv.net/gimg/bikefor...b34e5ce8ea.jpg



I often add a third chainring to do a direct comparison.
Here's 11-28 cassette and 34, 50 and 52 chainrings. You can see the difference is less than a half shift comparing 50 vs 52. That makes sense, since it's 4% higher (divide 52/50) and a typical shift is anywhere from around 6% to 12% depending on the tooth counts.
https://cimg9.ibsrv.net/gimg/bikefor...3a63cedd41.jpg



If you have an idea of your preferred cadences, and typical road speeds, you can see what ranges of speeds you'll get for each chainring. And how low do your gears need to be for the steeper hills you ride?

Maybe a 12-25 for flat areas, or an 11-32 for steeper climbs might be what you want. And Sram has a 11-28 with different tooth counts than Shimano, for closer shifts above 20 mph, but wider gaps from 15-20 mph.

I'm running a custom 14-32, for very close shifts from 18-25 mph, and low hill climbing gears, but it spins out at about 29-30 mph. That's perfect for me. But it's quite annoying on casual rides, where I'm shifting chainrings a lot in the 14-18 mph range.

I wanted very close shift points from around 18 mph to 25 mph, where I was working hard to hang onto the fast-for-me group rides. My other bike has much lower gearing, for all-day rides at a more moderate pace, and easier climbing of long, steep hills.

50/34 and 52/36 are usuallly 110bcd while 53/39 is 130bcd... atleast on the brands I am familiar with so you cannot mix the rings and arms obviously.

Newer Shimano 4-bolt cranks are the same BCD for compact and standard. You just need to swap the rings.

Is this for 5 arm or 4 arm cranksets? I haven't made the jump to 4 arm yet, so for 5 arm cranksets,

You may also be able to do 52/34, by simply replacing one ring on either the 52/36 or 50/34. It may or may not affect your shifting performance, or a possibility of chain suck.

With the 110bcd cranks, you can also replace both rings to go between "compact" and "mid".

You may or may not be able to find 53/39 rings for your 110 bcd cranks.

Are 4 arm cranksets coming in different BCD diameters, or are they all the same? That might mean just sourcing new rings of the desired size.

TMI, I just go with what my legs tell me. ;)

BBB.
The shift onto the big ring will suffer a bit from chainring flex though.