Assuming you run a 28t as second-to-biggest cog (e.g. what a Shimano 11 speed 11-32 has), your new (36/32) gearing will be 40% of the shift towards that 28t. I.e. somewhat easier than a gear in between your present easiest and next to easiest. Does this help?

About 5 rpm of cadence at same power same speed on the climb between the two.

https://www.bikecalc.com/speed_at_cadence

7% difference is huge on the lowest gear. For example at the same RPM and same crank torque at 300 W on a 34x32 on a 36x32 you will put out 21W extra. Or you will be riding at 300W but you will be 7-10 RPM lower. The reality is you will not magically gain watts so your RPM will drop. Depending on the steepness of the grade that could be an uncomfortable amount of crank Torque.

Where I live there are almost no climbs around that I cannnot do for extended periods on a 34x28, so I was fine on a 36x32.

Having said that, I much prefer the 50 tooth large ring because it allows me to stay in the big ring on moderate climbs and not do a chainring switch over and stay in a 50x28 (I don't use the 50x32 for obvious chainline reasons). Really, my perfect set up would be a 48/36 front chainring with a 11-32 on the back. I did Kona 2006 on a 48 tooth large ring and 34 small...it was perfect other than coming down from Hawi, but I was OK giving away a bunch of seconds and coast at zero watts and refuel. I used the big ring for almost the entire course other than Palani and a few of the up pitches going to Hawai. I only had a 12-25 then so my large gear was 48x12, not 48x11. I think for tri purposes, people over estimate the largest gears they need at an age group level....more important is low gear.


Dev

I literally made this switch about 2 months ago. I've been riding for 10 years, all of it with 50/34 exclusively, so i was a bit nervous/curious as well.

in short, i can barely feel it, if at all. i use an 11-28 out back, and i would say i can sense my cadence on steep hills in the 36/28 gear is a tad less, like a few RPM, that what it was with 34/28 but at no point have i been going along and thought "wow, I wish i had my 34t ring back". never. nor have i had to change the overall style of how I climb to compensate - it's a very subtle difference. I live in an area with lots of hills, lots of short steep ones too so I use my 28t cog a LOT. I have no regrets about the switch in the climbing regard.

I feel that on the flats and when descending, the 52t is nice compared to the 50t. I can be more in the middle of the cassette on flats, and when descending I feel like I have a bonus gear when I hit high speeds. I made the switch and I'm very happy.

when looking at gear calculators, I looked at bikecalc.com which had a "speed at cadence" function. I found that to be most helpful in seeing the differences, i'd recommend playing around with that. the ratios (like .07 you referenced) mean nothing to me so speed at cadence is very tangible metrics. I'd imagine "cadence at speed" would also be insightful, which that site has.

Unless you're regularly going up long 10%+ gradients, you're not going to find much of a difference between the 34 and the 36 especially with a 32 on the back (obviously exact gradient depends on your cadence and power to weight ratio). The 34-32 is about 5.5% easier than the 36-32, which is the difference of a few RPMs when climbing.

What you should be thinking about is how you ride on the flats and downhills as the 50 will be a much larger limiter at higher speeds. The group ride in my areas are absolutely flat out- we're talking 30mph average on the flats with surges and attacks. The groups will easily hit 40 mph on a few % downhill gradient. it's a lot less efficient to do those type of rides in a 50- you'll be in the 11 or 12 the whole time, and be vulnerable to accelerations on downhills as it's a lot easier to spin out. A 52-11 gives you a 14% higher top speed at the same cadence vs a 50-11, which is a big difference on those fast sections.

I run both on different bikes. I would only change to the 52/36 if it allowed me to stay in the big chain ring more often and I didn’t need to extra climbing ratio of the 34. In other words, if your typical riding has you dipping into the small chain ring frequently because it’s just inside the typical gears you ride, I would make the change to the 52/36.

I have a 52/36 by 28 or 30 (depends on wheels), and a 50/34 by 30 on two different bikes. I prefer the 52/36 – sometimes I feel like the 34 is too small and I wind up shifting more. The 52/36 has been amazing. After running a 53/39 by 28 (10 speed) on previous bikes, I find that the 52/36 gives a wider range. I live in a hilly area and the 36 is plenty for spinning up anything steep, but it's also as fast as I ever need on descents and flats. I feel like I shift chainrings less often than with any other combination, and I have seriously thought about changing the 50/34 on the other bike (except I'm planning on selling that bike anyway). I would recommend it if you're thinking about it.

4%

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No. It gives a 4% (52/50=1.04) higher speed with the same cadence and cog in the back.

Quick and dirty way to "imagine" the difference between making the jump from Compact (Small: 34T) to MidCompact (Small: 36T) while keeping the rear cassette constant is you lose 2T on the biggest sprocket. So for example:

If you're used to climbing in a Compact 34T ring x 32T cog, when you jump to a MidCompact 36T ring x 32T cog it is like riding in your Compact 34T x 30Tcog.

34T/32T = 1.0625
34T/30T = 1.133
36/32T = 1.125

36/32T is slightly easier than 34/30T. But it's "close enough" that if you have a 30T sprocket on your Compact bike, you can go hit up your regular climbs and stick to only using that second to largest cog to get a feel for what would happen if you went 52/36 x 11-32T... or whatever cassette range you have. Basically, go climb in the 34-30T and ask yourself if that's a deal breaker.

If you find that you miss those extra 2 teeth, but desire the 52T large ring to increase your top-end, then you can consider a +11-34T cassette with a medium RD cage. The trade-off being you have larger jumps between cogs as you approach your easier gears. Some care about that fidelity, others don't. Depends on the rider's flexibility with their cadence and respective power bands for said cadence.

I have 3 bikes each built with Compact, Mid-Compact, Standard... with very similar cassette ranges. The differences in feel absolutely come out in both the top and bottom ends of the gear ratios. Everything that happens in the middle range is a wash. You're either upshifting or downshifting one or two cogs to pedal at your naturally selected cadence.

What are you trying to accomplish with the chainring change? Increasing your low-end gearing when you're making frequent use of that bottom gear is usually a bad idea.

You could compensate for the bigger chainrings by changing from your 11-32 cassette to an 11-34 cassette. But Shimano's 11-34 cassette doesn't have a sequence of 1-tooth steps at the top-end, so if you're currently spending a lot of time in the 11,12,13,14 part of the cassette, you'll end up feeling wider gear steps. (If you aren't spending much time in the 11,12,13,14 area, then the 11-34 would actually be slightly tighter than your current cassette. It has closer spacing in the low gears.)

It largely depends where you ride. I live in a flat country and most of what I ride wouldnt be considered “hills” elsewhere, I mean there are steep sections, But most you Can easily sprint over. On my communter, I have 50/34 and 12-26 (it’s a 9-speed). I havent met anything I Can’t handle with 34/26 easy enough. Technically I could stay in the 50 all the time if I wanted to cross chain, But there are no long climbs. I could probably get away with a single speed.
I guess it depends wether you want a 52 Big ring or need a 34 small ring. You could just try 52/34 setup, just add a couple of links to your chain and see if it works

90 RPM in 34/32 is 7.5 mph

85 RPM in a 36/21 is 7.5 mph

Depending on front derailleur capacity. Most (?) have 16T capacity, although I'm not sure if pushing it to 18T will fail or not.

If you frequently use the 34/32, then keep the 34. If you use the 28 and the 32 is just a bailout, then the 36 might work.

My roadie is a 50/34 and my tri bike is 52/36, and I can definitely feel the difference when climbing, descending and sprinting. I'm OK with the more aggressive tri gearing since tri courses rarely feature super steep climbs, but there are lots of shallow descents that the 52 helps motor down.

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I was thinking that was the case. Thanks so much, big help!

Great advice, thanks! I have a lot of short steep hills too (Long Island) and I'm way heavier than I want to be and just not a climber so this is good to hear.

As fast as I'd like to think I am, I don't see myself running into the problems you have given. Basically all of my riding is by myself or on Zwift.

As much as you think your group is super fast, keep in mind that during the 60's and 70's and early 80's the biggest gears used in pro racing like the Tour de France was a 52x13.

To put this in perspective 52x13, this is the same exact gearing as a 44x11.

Check out the average speeds of the Tour de France in those years with that gearing and I am certain that they were riding faster than you guys (just like Frank Shorter ran the Munich Olympic Marathon faster than everyone on ST today and Mark Spitz swam all 6 of his gold medals at Munich faster than everyone on ST today).

Most people THINK they need larger gearing than they need. Fortunately bike product managers finally figured out what age groupers really need (based on all of us having to go after market and get compacts and large cassettes and finally cluing in that it would be a $400 competitive advantage if they just spec 50/34 and 11-32) and the funny part about all this was listening to George and Lance talking about their small gear being a 39x23 and maybe a 39x25 in training, but running the risk of being laughed out of the Peloton if they showed up with anything easier. But watching the TdF climb Col de Loz this year and you can see lots of guys on 36x32 (thanks Chris Froome for using a 32 in a TdF 2016 ITT to spin up the climb in Marseilles) so what age groupers are using is filtering back up to the pros!!!

Ask yourself why are you making the change? What is the motivation? That might help you decide. Do you find yourself needing a bigger gear?

I used to have 50x34. I didn't feel I lacked a big enough gear but I hated the huge drop between chainrings. One shift up front required usually 3 in the back.

So I just kept the 50 and replaced the 34 with a 36. It's the best of both worlds. And it was a lot cheaper. And it didn't require me to move my front derailleur up or down.

It's easy to do with Shimano DA and Ultegra. Not sure about others.

For solo riding I would stick with the 50/34. I rode for probably 3 years on a 50/34 and there were times in races or group rides where I would be pretty maxed out cadence wise and wouldn’t have survived an attack, but I can never say I got dropped because of the 50. On the flip side it is always nice to have an easier gear when you need it.

Exactly this. I bought a bike, and didn't bother to check the chainring ratios assuming it's a compact. About a month in, after a 3-day training camp with 7000m of altitude gain, I bothered to check - huh, turns out it's a semi-compact. I was still in the big chainring for most of my riding, I was in the small chainring in the same places I usually would be, I guess maybe a cog easier than usual in the back - but nothing dramatic.

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Not much difference unless its super hilly and even then you can hardly tell a difference. Since you can change the gearing on the cassette too you can make a 50/34 feel like a 52/36 so its really a moot point.....again, on 90% of the terrain out there.

This will help you visualise it and play a little to see what can be achieved.
I have pre-loaded your above to setups.
http://www.gear-calculator.com/...5,28,32&UF2=2135