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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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For a road bike i'd agree thats pretty optimal. For tri/tt I'd go for an 11-25
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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Haven't used one in a while though
[I DID recently find a boxful of mixtapes in the basement]

"What's your claim?" - Ben Gravy
"Your best work is the work you're excited about" - Rick Rubin
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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I wouldn't swap out a 52 for a 50 unless you're going to change the small ring too. It's probably cheaper to buy both an 11-28 and a 12-25. Then replace the 11 and 12 in the 11-28 cassette with the 12 and 16 in the 12-25 cassette. You'll still get the range, but you'll have smaller jumps. (I'm assuming you're on 11 speed).

My gear ranges for mostly rolling hills with a few sustained climbs:

Allroad/Gravel bike: 46/33 with 10-33 or 10-36 (pending wheelset)
Tri: 48/35 with 10-28 (use to be 52/36 with 11-30 or 11-25 depending on course)
Road: 52/36 with 11-32
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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11-28 in hilly races. 12-25 for flat races. Takes 5 minutes to swap out.
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Re: What's your standard cassette size? [HTupolev] [ In reply to ]
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HTupolev wrote:
JoeO wrote:
A 34 certainly buys you higher cadence if you want it, but I think most people can manage at 50 RPM

It maybe depends on your expectations and what "manage" means. 50rpm is far below most people's self-selected cadence even on steep climbs, and when it's the average over a lengthy stretch, it's likely imposing a significant cost in power output and fatigue. But doable? Sure.

Cyclists get panicky when the cadence drops too low. I've had a few experiences when I thought I was going to fall over but eventually, at some really low cadence I didn't enjoy at all (like 30s and 40s), I hit an equilibrium and it became manageable; I could at least keep going in a straight line and temper my power. But only when I didn't overdo the lower part of the climb. If you blow a gasket, it doesn't matter how low a cadence you could otherwise handle.
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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When I started riding (with a strong running background), I bought a Cervelo tri bike that came with 53/39 and 11/23 cassette. I never knew those could be changed and just dealt with it.. if it was hard then just suck it up.

Then I signed up for St. Croix 70.3 which I think has like 23% the "the Beast"... their website strongly encouraged an 11/26 at least unless you were a pro. That's when the light dawned I had options - I swapped it out and it was like a whole new world out there. Nowadays I mostly ride my road bike with a compact crank and I love my granny gears! (Of course I'm also 15 years older than when I bought that bike!)
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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I chose 52/36 chainrings when I upgraded the groupset on my road bike. I went with a Shimano 11-30 cassette at first.

Living in Minnesota, I don't face a lot of extended climbs. There are some short steep ones not far from me. In general, I've basically never used the 11t. I dislike the 15-17 jump, and I frequently wish for a 16t. It's not so bad, but I find the 21-24 jump to be a bit large also. So, I would like a 12-28 cassette. The interesting thing is that with Shimano, you can take a 12-25 cassette, extract the 12-17 cogs, and mate those to the 19-28 cogs from an 11-28 cassette.

I chose 52/36 up front because it was a bit closer to the 53/39 I was coming from and because I expected the bigger rings to translate to slightly lower chain friction. I'd consider a 50/34 in the future, but in that case I think I'd be more inclined to get an 11t small cog, just in case.
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Re: What's your standard cassette size? [exxxviii] [ In reply to ]
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Echoing a few comments above, I rarely use my 11t cog. IMHO, that is a waste of realestate. My perfect cassette would be a 12-23 for flat courses and a 12-25 for hillier courses.

My primary cassette is a 11-23, and my occasional use cassette is 11-25. I have only raced on a 11-28 once, and that was the WC in Nice. If I could ditch the 11 tooth across the board, I would be a happy camper.
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Re: What's your standard cassette size? [weiwentg] [ In reply to ]
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weiwentg wrote:
I chose 52/36 chainrings when I upgraded the groupset on my road bike. I went with a Shimano 11-30 cassette at first.

Living in Minnesota, I don't face a lot of extended climbs. There are some short steep ones not far from me. In general, I've basically never used the 11t. I dislike the 15-17 jump, and I frequently wish for a 16t. It's not so bad, but I find the 21-24 jump to be a bit large also. So, I would like a 12-28 cassette. The interesting thing is that with Shimano, you can take a 12-25 cassette, extract the 12-17 cogs, and mate those to the 19-28 cogs from an 11-28 cassette.

I chose 52/36 up front because it was a bit closer to the 53/39 I was coming from and because I expected the bigger rings to translate to slightly lower chain friction. I'd consider a 50/34 in the future, but in that case I think I'd be more inclined to get an 11t small cog, just in case.

Why not get the 12-28 cassette then? You don't have to mix two cassettes to get it. The 12-28 range is s a standard Shimano cassette - at least for 11 speed

The number of times you'll miss the 11-tooth ring absolutely pales in comparison to the number of times you'll miss that 16. And I only run a 50 up front.
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Re: What's your standard cassette size? [jaretj] [ In reply to ]
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jaretj wrote:
They are saying it would take 300 watts to ride at a rate where the bike can still stand up. I don't think many people can ride up a hill at .2 mph and not put a foot down.

.2mph on a 20% gradient for 300W would imply that you weigh around 3500lbs, though.

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What's the slowest you are capable of riding and still stay up? 2 mph?

I'm not entirely sure, since I haven't run into the limit on smooth firm surfaces before. I've certainly had trouble on rough off-paved stuff, but there's more to that than just the gradient.

If my limit were 2mph, I'd note that that's in the 2.2-ish W/kg ballpark for someone riding a 20% gradient on a road bike. It's unlikely to require 300W unless a rider weighs more than 300lbs. For a 180lb rider on a 20lb bike, it's in the ~175W neighborhood.

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At 300 watts I couldn't keep the bike moving forward at a rate I could handle so I weaved across the road.

Would you have shifted to a lower gear if you'd had one, though? If the answer is yes, then I'm not sure that your conclusion is valid.

When your gearing is bottomed out, speed is necessary to balance not just because it directly aids balance, but also because when you're torque-limited, speed (being proportional to cadence) is necessary to power production. That is, when your gearing is bottomed out, dropping your speed makes it more difficult to produce enough torque to maintain a given power, and thus, maintain speed. A nasty feedback loop.

So the complicated question becomes: was 300W your lower balance limit because you actually couldn't balance at speeds lower than what you achieved at 300W, or was 300W your lower balance limit because 300W was the minimum power that could be sustained on those gradients at the torque delivery that your legs can deal with? Zigzagging can help with both the former and the latter due to increasing speeds, but it can further help with the latter by effectively "lowering" your gearing and making it easier to provide power.
Last edited by: HTupolev: Dec 3, 20 20:47
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Re: What's your standard cassette size? [HTupolev] [ In reply to ]
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HTupolev wrote:
jaretj wrote:
They are saying it would take 300 watts to ride at a rate where the bike can still stand up. I don't think many people can ride up a hill at .2 mph and not put a foot down.

.2mph on a 20% gradient for 300W would imply that you weigh around 3500lbs, though.

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What's the slowest you are capable of riding and still stay up? 2 mph?

I'm not entirely sure, since I haven't run into the limit on smooth firm surfaces before. I've certainly had trouble on rough off-paved stuff, but there's more to that than just the gradient.

If my limit were 2mph, I'd note that that's in the 2.2-ish W/kg ballpark for someone riding a 20% gradient on a road bike. It's unlikely to require 300W unless a rider weighs more than 300lbs. For a 180lb rider on a 20lb bike, it's in the ~175W neighborhood.

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At 300 watts I couldn't keep the bike moving forward at a rate I could handle so I weaved across the road.

Would you have shifted to a lower gear if you'd had one, though? If the answer is yes, then I'm not sure that your conclusion is valid.

When your gearing is bottomed out, speed is necessary to balance not just because it directly aids balance, but also because when you're torque-limited, speed (being proportional to cadence) is necessary to power production. That is, when your gearing is bottomed out, dropping your speed makes it more difficult to produce enough torque to maintain a given power, and thus, maintain speed. A nasty feedback loop.

So the complicated question becomes: was 300W your lower balance limit because you actually couldn't balance at speeds lower than what you achieved at 300W, or was 300W your lower balance limit because 300W was the minimum power that could be sustained on those gradients at the torque delivery that your legs can deal with? Zigzagging can help with both the former and the latter due to increasing speeds, but it can further help with the latter by effectively "lowering" your gearing and making it easier to provide power.

That was an exaggeration I thought was obvious

So you don't know how slow you can effectively ride

4.5mph at 20% for a 75 Kg rider+bike is 300 watts, again an exaggeration on my part, my fault

Don't know what conclusion you're referring to, if it was about weaving across the road, you should try riding 20% straight up for 10 min. If you don't have an FTP of 5W/Kg (which you may have) you aren't going straight up

Yes, that's the point

Your last statement doesn't make much sense to me without considering someone riding with a cadence of 50-55 rpm, which is what the posts from exxxviii and lightheir were all about (300 watts to keep moving)
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Re: What's your standard cassette size? [JoeO] [ In reply to ]
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JoeO wrote:

Why not get the 12-28 cassette then? You don't have to mix two cassettes to get it. The 12-28 range is s a standard Shimano cassette - at least for 11 speed

The number of times you'll miss the 11-tooth ring absolutely pales in comparison to the number of times you'll miss that 16. And I only run a 50 up front.

I believe the 12-28 is only offered in Dura Ace. Shimano’s own page for its Ultegra cassettes lists 12-25, 11-25, -28, -30, and -32. I would expect the ti cogs to wear way too fast, plus it’s actually cheaper to buy two separate Ultegra cassettes as far as I can see.
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Re: What's your standard cassette size? [jaretj] [ In reply to ]
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jaretj wrote:
...you should try riding 20% straight up for 10 min. If you don't have an FTP of 5W/Kg (which you may have) you aren't going straight up
^This.

My hunch is that HTupolev does not have much experience riding very steep grades. My "300W" was a little hyperbole, but not much. I am a fairly powerful 80kg rider, and I recall being around 5 MPH on >20% grades and at or above 300W.

The other key thing behind my "gearing is irrelevant" comment is that at >20%, low speed, and low cadence, going from a 28, to a 30, to a 32 cog only changes your cadence by around 5 RPM when you are down in the sub-60 range. At that point, as you said, you are not going straight up, and the gearing won't solve that.
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Re: What's your standard cassette size? [weiwentg] [ In reply to ]
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That's a bummer. I never realized that.

Shimano's cassette choices (i.e. which ones to make in which combinations) have always perplexed me.
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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With my 52-36 rings:
12-25 for general training
11-23 for racing on a flat course (e.g. Steelhead)
11-25 for racing a rolling course (e.g. IMWI)
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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I love the 52-36 with 11-30 cassette combo on the road buke- the range is absolutely fantastic! Sure I don't spend much time in the 30, but any time I hit a sustained grade of 10%+, I am sure glad that I do have it. If you're racing, this also allows you to stay in the big ring on short punchy climbs. I don't live too far from the blue ridge mountains and while I don't need the 30 on most of the climbs, I would rather have the extra gear than be stuck with only a 28 when my legs are fried.

To this last point, one of the dumbest things I've ever done is Everest on a climb with .6 miles at 12% avg (15% max). My 36-30 was NOT low enough for third quartile of the ride- I was grinding away at 50rpm using my whole body. My back hurt hurt than anything the next day. I really wish I had a 50-34 with an 11-32 or an 11-34 that day.

On my TT bike, I have a 55-42 Q rings with 11-28 on the training wheels and 11-25 on the disc. That is the perfect gearing for me, especially because I tend to ride at ~80-85 cadence on long distance tris. I previously had a 53-39 and found that I was spinning out or spending a lot of time in the 11-13 (I live in an area with a lot of rolling hills). It's not a massive difference, but I do think the Q rings help me to pedal more smoothly in the TT position, especially when going uphill at lower cadences. I would be comfortable racing the 11-25 on any races with sustained climbs up to 6%, and the 11-28 on sustained climbs up to 8% before I'd start looking for other gearing options.
Last edited by: mikeridesbikes: Dec 4, 20 12:58
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Re: What's your standard cassette size? [dave_o] [ In reply to ]
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12-25 on all road wheelsets. Bad that Campagnolo dosen’t have 13-25/26 11-speed Record cassette - would take it immediately. (Terrain is mostly flat with some occasional sharp few hundred meters hills).
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Re: What's your standard cassette size? [jaretj] [ In reply to ]
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jaretj wrote:
So you don't know how slow you can effectively ride

Well no, because I haven't specifically tested my limit. I do know for sure that I can sustain <3mph without trouble, because that happens sometimes while riding mountainous gravel.

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Don't know what conclusion you're referring to, if it was about weaving across the road, you should try riding 20% straight up for 10 min. If you don't have an FTP of 5W/Kg (which you may have) you aren't going straight up

Assuming riding the steep 10-minute section at threshold, 5W/kg on a 20% gradient is going to land most cyclists at about 4.5mph. If I can balance just fine below 3mph on gravel, why do I need to go 4.5mph in order to ride straight up a 20% paved road? That doesn't make any sense.

Unfortunately I don't know of any stretches in my area that sustain 20% for a length that takes me 10 minutes to ride up. But on 20% stretches that I have ridden, I do know that I don't need to go anywhere near 4.5mph to stay balanced.

The steepest 1-mile stretch that I know of nearby averages about 16%. It's rutted gravel double-track, which makes staying upright trickier than on pavement, and it does have spots that get into the 20% ballpark. But my FTP is less than 4W/kg, and I do not need to put out a maximal effort to ride straight up that stretch.

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Yes, that's the point.

Your last statement doesn't make much sense to me without considering someone riding with a cadence of 50-55 rpm, which is what the posts from exxxviii and lightheir were all about (300 watts to keep moving)

Right. I'm examining the example of someone needing high power (i.e. 300W on 20% gradient), and suggesting that this is in part due to the gearing (and thus cadences) involved. This is in response to yourself and others suggesting that reduced gearing would not help.

exxxviii wrote:
The other key thing behind my "gearing is irrelevant" comment is that at >20%, low speed, and low cadence, going from a 28, to a 30, to a 32 cog only changes your cadence by around 5 RPM when you are down in the sub-60 range. At that point, as you said, you are not going straight up, and the gearing won't solve that.

Okay. As I explained here, my comments have not been assuming typical race gearing.

On my gravel bike, for instance, my lowest gear is around 19". For context, on a bicycle with 700x25 tires and a 34T small ring, that would take a big cog of around 47 teeth.
Last edited by: HTupolev: Dec 4, 20 23:31
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