When I was dumb I used a 58-t ring on a bike. I wanted to go 50.
A 58 isn't necessarily dumb, it just hinges on what you have on the rear. I do see a lot of people talking as if one doesn't involve the other or failing to think about how the ratio is what matters, not the gears themselves so much.
It's a lot like aviation fanboys who run their mouths about "this plane can do 9g's!!!" as if that magically makes it more maneuverable without the all-important question "yeah? At what speed?" A 9g turn at 450 knots
(F-16A's best turn) and a 6g turn at 300 knots
(well within the F-4 Phantom's flight regime) are the same rate of turn and turn radius.
There was this whole hubub about the F-35's corner velocity and g rating being lowered making it "less maneuverable" when in fact the rated change made it more maneuverable with less string on the pilot.
Sorry for the tangent. Aviation was my first love until my eyesight went to s*it 30 years ago.
Anyhow --
whilst I am running one -- an 11 tooth rear is kind of ice-skating uphill in terms of just space for the chain to grip. It's why you don't see a lot of cogs smaller than that. My original plan for mine was to put a 58t chainring I already had in my spare parts on it, but it didn't clear the frame. Thing is I would likely have gone with a 12..42 on the rear as that's basically the same as the 53:11-36 I'm running now. That low 58:42 being near identical to the stock 44:32 the bike came with.
Simple division and multiplication. It's not the size of each of them, its' the ratios. That's where I think the confusion sets in for many is we say something like 44:12 or 58:15 when in fact they're spitting distance from each-other.
58 / 12 == 4.83333~
53 / 11 == 4.83838~
A hair under 5:1 is not an excessively absurd ratio.
For reference the stock on mine
44 / 12 == 3.6666~
If we wanted to come close to that, these are all "close enough"
58 / 16 == 3.625
58 / 15 == 3.86666~
53 / 15 == 3.53333~
53 / 14 == 3.78567...
Same on the low end. My Aventon stock (again, 44 when they advertised 46) vs. possible 53 and 58's.
44 / 32 == 1.375
58 / 42 == 1.3809...
53 / 38 == 1.3947...
And what I'm running on the low end is a hair under 7% more:
53 / 36 == 1.47222~
That's why it's more about dialing it in for you, instead of blindly hoping that what came stock meets your needs. Would I recommend the 53:11..36 I'm running for everyone? Of course not. Some might need more. Some might be fine with the 44:12..32 it came with. Some might need to drop down to as few as 32 on the front with anywhere from 32 to 48 on the rear if they do lots of climbing.
It's why the folks who say you've "messed up the low end with the chainring swap" seem to be magically unaware that you can change the rear cogs too.
Hell I know a guy running a 72 on the front he custom made on a flowjet just for looks, who's set up a 20..48 on the rear. I'll see if I can find some pics of that. It sounds absurd, and in terms of weight it is, but his gear ratios range 3.6x to 1.5x -- narrower than what most off the shelf 8 speeds come with stock and inside the relative range of ratio multipliers.
