What's your standard cassette size?

Triathlon Forum
21

At 20-22%, it takes me 300 watts just to stay moving at a crawl. Going any slower is barely possible, and it’ll definitely suck.
At 20%, I can’t get below 300W and still be moving.
I really don’t understand what you two mean by this. There’s no such thing as a gradient requiring a certain amount of power in order to keep moving forward. No matter how steep the gradient, any power at all implies forward motion.

It’s possible for your gearing to demand a high effort in order to keep the cranks turning fast enough to keep the torque-vs-cadence balance of your pedaling in a reasonable range. But that’s explicitly a gearing issue, not an issue irrespective of gearing.

I’ve sometimes heard people claim that balance becomes an issue climbing at very low speeds. But in my experience, this issue rarely seems to actually manifest itself. Riding at walking speeds on flat ground can be tricky because you’re not able to use the reciprocating roll of pedaling form against drivetrain resistance as a balance mechanism. But when you’re riding uphill and pedaling normally, on a firm non-technical surface, even speeds considerably less than 3mph aren’t especially difficult for most people.

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.

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.

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

The last time I went up Brasstown Bald in the Georgia Mountains I tried to go straight up “the wall” with a 34 chainring/36 cog on the cassette, on 650c wheels and wasn’t strong enough to do it, and that’s a lot of gear. At 300 watts I couldn’t keep the bike moving forward at a rate I could handle so I weaved across the road.

https://pjammcycling.com/climb/600.Brasstown%20Bald middle of the page is the profile and the steepest grade is 15 to 18%

https://pjammcycling.com/climb/600.Brasstown%20Bald

How common are 20% grades? I have never ridden up anything that steep in my life.

Oh, and gear ratio’s have nothing to do with the power requirements to ride at a given speed. They affect the force at the pedals, not the power.

22

“How common are 20% grades? I have never ridden up anything that steep in my life.”

“Oh, and gear ratio’s have nothing to do with the power requirements to ride at a given speed. They affect the force at the pedals, not the power.”

Not very common so when I know I’m going to be doing something close I bring the gear for the job.

Yes, sure but I cannot produce 300 watts at 20 rpm for more than a few seconds.

Going uphill at Xterra Champs in Maui I was pedaling 50 rpm with a 32/46 because it was so steep, because of that I didn’t make it up the climbs without putting a foot down. Had I been running a 30/50 like a lot of others had, I would have been spinning 10 rpm faster and possible making it uphill without stopping.

23

“How common are 20% grades? I have never ridden up anything that steep in my life.”

“Oh, and gear ratio’s have nothing to do with the power requirements to ride at a given speed. They affect the force at the pedals, not the power.”

Not very common so when I know I’m going to be doing something close I bring the gear for the job.

Yes, sure but I cannot produce 300 watts at 20 rpm for more than a few seconds.

Going uphill at Xterra Champs in Maui I was pedaling 50 rpm with a 32/46 because it was so steep, because of that I didn’t make it up the climbs without putting a foot down. Had I been running a 30/50 like a lot of others had, I would have been spinning 10 rpm faster and possible making it uphill without stopping.

The big issue that I find is that in a mountain bike scenario, it’s typically fine in the harder gear at 50 rpm (other than the quads screaming at you to stop, of course), but it’s way easier for terrain features to stop you because you can’t pedal through the low power zones of the pedal stroke as easily. I never have an issue when the cranks are level, its at TDC. That really applies to any slow speed sections, whether flat or climbing.

24

11-28.

25

**Triathlon **
Stayin’ alive with 11-25flat and fast is 11-23 mountains is 11-28Verve Infocranks 52-36 , 155mm length
**Road Bike **
Crank: Shimano 105 R7000, 50/34 (compact), 172.5mm length Cassette: Shimano 105 R7000, 11-30, 11 speed

My setup is virtually identical to this for **triathlon **and road.

**Triathlon, **my only difference is I’ll go 11-30, 11-32, or 14-32 (cassette mash-up) for mountains. I’m 94kg and train recreationally :wink:

For **road, **I have 53-39 up front because it’s what came on my bike at purchase. Same 172.5 cranks. I’ve made up for the loss of climbing range with an 11-32 (11sp) cassette.

26

For a road bike i’d agree thats pretty optimal. For tri/tt I’d go for an 11-25

27

https://www.wired.com/images_blogs/gadgetlab/tdk_d_90_c.jpg

Haven’t used one in a while though

.

28

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

29

11-28 in hilly races. 12-25 for flat races. Takes 5 minutes to swap out.

30

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.

31

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!)

32

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.

33

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.

34

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.

35

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.

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.

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.

36

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.

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.

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)

37

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.

38

…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.

39

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.

40

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)