Is my gearing fine?
 

I'll try to make this short. My bike came with a 50-34 crankset and an 11-34T cassette (8-speed). I don't live in the mountains and I very rarely used the 34T cog. A few months ago, I replaced it with an 11-28T since I was struggling with the large gaps between gears. Recently, I've found myself frequenting a short but steep climb here in my area. It's under 7 km long, 614 m high with an average gradient of 9.1%. It has a couple of super steep areas that are 20-30%. Looking at my data, my cadence hovers around 40-60 in the duration of the climb, which is low. However, I don't experience any knee pain (and never have since I started cycling more than 2 years ago). I do feel out of breath, which goes against what I read that lower cadence is more taxing to the muscular system than the cardiovascular system. My best time is 45 minutes.

Do you think my present gearing is fine, or should I swap it out ASAP? I do plan on going to 11-30/32T in the future, but that's a long way from now and maybe by then, I'd have bought a different bike. Side question, do low cadence workloads make me a stronger cyclist?

Keep in mind this is the only prolonged climb that I ride. I used to do centuries without even breaking past 1000 m of elevation gain. I hope that's a good illustration of the terrain here.

No Right Answer.

As for being out of breath .... yes, in general, spinning faster puts more load on the cardio systems, and spinning slower puts more load on the muscles (because in part, the cardio system has to flush more frequents spurts of waste because you are pedaling faster) but no matter what, you are using your muscles continually for 45 minutes ..... are you thinking it would be easy, climbing that 20% hill.

Taken to the extreme (reductio ad absurdum) if you only pedaled one stroke per minute you wouldn't get tired and would just float up the hill, right? Sorry, but climbing a 20% grade Walking is tiring. Cycling it is tiring in a different way.

Personally, I would think 40 rpm would be too low to be efficient, because you would lose too much momentum between pedal strokes---but you made it. 60 is definitely grinding, but some riders prefer that. You have to listen to your own physiology (and remember, you are taking hill-climbing advice for m a rider who is challenged by three percent for 700 meters, forget 30 percent for seven km.)

Personally, if that climb were part of my regular route, I would replace the 11-34 ... but I couldn't make that climb with an 11-46 or 10-51 or any gear, so ..... I do like the 11-28 for most terrain because it goes low enough (for me) to make the hills and is nice and tight in the small-mid cogs .... but seven km at 20-30 % is a well, 45 minutes and that would take a lot out of me.

Generally speaking, based on your one short post (what doctor wouldn't prescribe life-changing medical regimen to a guy he met online after two paragraphs of description?) I'd say toughen up until you can keep the revs above 60 .... using whatever gearing you needed. But if you are strong enough (joint-wise, not in terms of muscle) to ride it with 34x28 .... good for you. I would worry about knee strain, but if you are paying attention you might be fine.

Or you might post a week from now about how you need double knee replacement. I wash my hands of all legal liability.

I weigh 175 lbs and to barely keep moving up a 25% slope I need to be putting out around 300W. I can grind my way up with a 1:1 gear, but it isn’t pretty and I am going to be out of breath pretty quickly regardless of the ultra-low cadence! If I was climbing this kind of gradient more regularly I would go even lower on gearing as there is no real chance of spinning out on 20%+ climbs!

Just to add, we do have a fair few local climbs with segments in the 20-30% range and I use a compact 50/34 crankset with an 11-34 cassette (11 speed). I wouldn’t even think about switching to a smaller cassette for these climbs.

It's all up to you. If you're okay with current outcomes, no need to change. Lower gears will allow you to get up the steep bits with slightly higher cadence, but you know that. Lower gears may improve your time... or not.

That's a good climb and elevation for me. I would need/want the 1 to 1 gears. I have found the lower to gears to not be any faster but a lot more enjoyable going up the hill. In my case my knees hurt going up hills that are 10% + over 2+ miles when I had 36 front and 30 rear. Now I have 30 front and 30 rear.

At least for me I noticed zero difference in cardio or time going up the hills using different gears. For me it was all in the knees. Night and day different grinding up vs spinning up.

Wait. So you had a 34t cassette and then you took it off because you weren't riding up big hills, but now you are riding up big hills and wondering if you need lower gearing? Why not put the 34t back on and see if that works better?

That's a range where most people are losing a tangible amount of performance. If you're frequenting this hill, you'd likely benefit from substantially lower gears.

If you didn't resize your chain and you still have the 11-34, try popping it back on and see how the climb feels.

If you’re going to be going up that steep climb regularly, then put the 34 back on, and keep it on until you can climb that hill in 2nd gear.*

if you’re only going to climb it occasionally to test yourself, keep the 28 on, and try to maintain 45rpm up it next time.


*I don’t know your limits or if you’ll ever get to the stage of comfortably climbing the hill in the 30 cog, but it’s worth having a goal, right?

For those 20-30% pitches a 34T is always going to be useful, even if he can climb the easier parts in a higher gear. Cadence is never going to be too high climbing up those.

You might consider putting a 3x front on that bike. With the 8 speed 11-28T on the rear, you'll have a lot more gear combos available to you. And when in the small front ring be even lower ratio than the 34/34 of your original configuration.

Though you'll have to find a new or used 3x crank and BB that will work on your bike. If you are indexed shifters, then you'll need a 3x indexed shifter too. But conceivably less than 100 bucks if you can do the work.

IMO, if I was climbing a hill at less than 70 RPM for an period of time I'd have sore knees. My normal cadence for anything is 85 to 95 RPM. I haven't had knee issues for a long time.

Same here. When I think of 45 minutes at 45 rpm up a really steep grade .... well, I just don't I can watch horror movies on TV, why imagine starring in one?

I stupidly gave the 34T cassette to a friend.

I aim to do the climb once a week/every two weeks but with my semester coming up next week, this is probably not gonna happen.

With a 50-34 and a 11-30 there are two nightmare mode climbs where the gearing is essentially insufficient. Both are over 20% and concrete instead od asphalt and my cadence falls to 40ish.

My solution is to do them on my gravel bike which has lower gearing. At the ends of the climbs there are gravel bits, anyway, so that makes more sense.

There are a few road climbs with really steep ramps but I wouldn't want to lose the nice tight spacing of the 11-30 cassette which in 11 speed is really perfectly balanced.

If we're talking about full reconfiguration with a crank swap, here's my gravel bike's 3x8 drivetrain with 48-38-24 chainrings and a standard Shimano 11-13-15-18-21-24-28-32 cassette:

https://i.imgur.com/oUFqt3q.png
The 2x8 formed by the larger two chainrings forms a reasonable road drivetrain, and the 24T ring gives me a bailout for steep stuff.

That's a LOT of gear overlap. Also a LOT of chainring shifting if you are going to make any use of it!

Yes, but the double-shifts aren't actually that bad: the 10-tooth front shift is substantially snappier and less disruptive than a shift on a wide-range double, and the compensatory rear shifts are small. The situations where tight shifts are most useful also tend to be situations like cruising along shallow undulating terrain, where a slight ergonomic clumsiness in the shift isn't a huge deal. I do actually take advantage of the tight shifts frequently when riding the bike.

Well you can decide yourself if it’s worth swapping the cassette back for this one climb, or if you’re going to be doing enough climbing to make the bigger sprockets necessary, or if you would miss the gearing on your other rides.

Where do you find a 25% grade? That's huge.

The Peak District in the UK. Loads of them there. I did an event earlier this summer called the "Peak Epic" and there were multiple climbs with this kind of gradient. Really brutal stuff and to be honest not very enjoyable! There are also quite a few climbs in the Cotswolds with 20%+ pitches, but shorter segments. Last year I did a ride called the "Baker's Dozen" with 13 brutal climbs. Then there's the Lake District further north, again with brutally steep pitches that even some cars struggle on. To be honest I prefer Alpine climbs with their more consistent 6-10% gradients.

Interesting thing with the above climbs, every year guys turn up with big chainrings and small, tight cassettes and wonder why they find themselves forced to walk. A quick check on Bike Calculator shows that a 175 lb rider needs to put out 322W to crawl up a 25% slope at 3 mph. Or 520W at 5 mph! So unless you have a 400+W FTP you need some pretty low ratios to sustain this kind of climbing for any length of time.