Koyote

Once again, you fail to understand a common cycling term. And yet, you act all snippy with the people who are using the term correctly.

LesterOfPuppets

Me too. I've done em in 26x32, with 26" wheels.

Atlas Shrugged

GRX 48 - 31 Chainwheel. 11 - 36 SRAM cassette.

phughes

As someone with ~25% grades within a 2 mile radius of my house, I will second the triple recommendation. I have a 24 up front and a 34 is the biggest on the back. It works. If not a triple, at least find a compact double that lets you get that low, or go all the way to a single with a small ring, of course you lose your large ring doing that.

BoraxKid

Literally what are you talking about? Once again, everything I've said is technically correct, and yet you people are acting like I've said something blasphemous. From context, it sounds like you are assuming "spin" implies a certain cadence, when in fact it does not. The way you are using the "spin" sounds more like you learned it from riding a stationary bike (i.e. spin class) than from anyone that rides outdoors. I use the word spin exactly as I've heard many, many experienced cyclists--including former pro cyclists--use the word. If that upsets you, then that's just your burden to bear from now on. Good luck.

LesterOfPuppets

The terms spinning and mashing pre-date "Spin classes" by many years.

Spinning typically denotes higher cadence work.

BoraxKid

No, it doesn't. Maybe you missed the context, but we're talking about climbing here, so it is implied that "spin" does not refer to hamster-wheeling along at a high rpm like you're on a stationary bike. Go watch any video where the GCN folks talk about "standing vs sitting" while climbing (I think they've made about a half dozen of those over the years). They always acknowledge that going uphill means your cadence will naturally slow down, and they show themselves climbing in the saddle while spinning at relatively slow cadences c.f. when they are on the flat.

fietsbob

there are 46-30 doubles .. 46:12 , is a 1:3.8333... gear ratio which should be adequate.. on a 700c/29er wheel ...

tomato coupe

I'm starting to think that the entirety of your cycling knowledge comes from watching videos.

HTupolev

That's not a useful way to compare gear ratios, what your legs feel is the ratio between them. That's what tells you how much your torque and cadence will change by if you shift between them. (34/11)/(34/12) is a roughly 9% gear increase; (34/30)/(34/34) is a roughly 13% gear increase.

Let's assume that bike+rider is 80kg, or ~176lbs. Suppose they've got a CdA of .32, and their tires are enjoying a crr of .005 on the road surface they're riding. Let's assume that they're roughly at sea level, and the air density is 1.225kg per cubic meter, and the gravitational acceleration from the Earth is 9.8 m/(s^2).

90rpm in a 34-40 is about 2.69m/s on a 25mm 700c wheel, so:
Power from rolling resistance = 80 * 9.8 * .005 * 2.69 = 10.54W
Power from air resistance = .5 * 1.225 * .32 * (2.69 ^ 3) = 3.82W
Power from gravitation resistance = 80 * 9.8 * .25 * 2.69 = 527.24W
So the total power is about 541.6W, without factoring in bearing drag. If we assume that the rider in this 80kg bike+rider system is about 72kg, this is roughly 7.5W/kg effort, which is monstrous.

Dropping that down to 65rpm, we change the velocity to only 1.94m/s. Repeating the calculations with this new value, we get a total power of 389.28W, or 5.4W/kg. That's still a pretty intense effort for most cyclists. And 65rpm is really starting to lug for most people, even in climbing form.

The phrase "sit and spin" doesn't imply a specific cadence, but it generally implies that a person is staying well on top of their gearing and pedaling out a cadence that doesn't feel slow to them. It doesn't simply mean that the cranks haven't stopped going in circles. 65rpm is lower than most experienced cyclists self-select when seated, even during a climb, so it's typically inappropriate to refer to it as "spinning" in a general context (but I'd acknowledge that there are exceptions, since some people naturally self-select very low cadences).

trailangel

Chill out.....and relax. Spinning refers to sitting on the saddle and pedalling a lower gearing, getting on the top of the gearing.
Or you can stand on it in a slightly higher gearing at a lower cadence... or sit and mash at a lower cadence in a higher gear.

Bill Kapaun

+1
Due to age & medical issues, I simply can't "mash" because my knees will be screaming, so I "spin" a lower gear.
Now my "spin" is very slow (60-65), but for me it's NOT MASHING.
It's RELATIVE!

GAtkins

So you're gonna climb a 25% grade with a 46 chain ring and 12 on the cassette? How's that gonna work?

Glenn

70sSanO

I apologize if my terminology is not technically correct, I gladly accept being called out on any of it, as I don't really give a ... It is merely based on my riding and not on any research or classes, which I have never taken.

When I first started riding years ago,

Spinning was always, turning the cranks smoothly at a high rpm. BITD it was 90 or more.

Sprinting was getting out of the saddle for a quick climb or pass.

Grinding was basically a low cadence smooth spin and you just worked your way up; just take your time and enjoy the moment.

Mashing usually occurred when you couldn't smoothly grind up and needed a forceful up and down, or just down, stroke on the pedals.

Stair-stepping was used when all else failed and you just needed to get up the hill and you basically very slowly walked your bike up on the pedals, typically in a slightly higher gear.

Falling over usually occurred at the point of exhaustion and you couldn't stair step any more. But with enough practice one could anticipate this and successfully come to a complete stop and not fall.

I have mastered all of the above on any given occasion.

John

woodcraft

I've been running 34:34 for a while. On local ~20% bits, likely be going 4 mph at 50 rpm or worse.

If I had a 40t, I could 'spin' at almost 60 rpm. Don't know about the sitting up apart, 'tho...

Iride01 

Maybe it should be a forum practice that we each provide a glossary of terms with every post we make. <grin>

DiabloScott

Spinning absolutely requires sitting vs standing, it absolutely implies a smooth stroke as opposed to mashing; it more or less implies a cadence in the upper end of normal - 60 at least for climbing, 80 or more for flats.

Yeah, everybody's got a plan until they get punched in the mouth.



My cadence here is probably about 70rpm, and my heart rate is 160+

fietsbob

No, Fool ! willful ignorance?

how about the 36:30 ..

I toured Europe West to East & back & British Isles years ago

high 13:50. Low 24:34..

2 foot gear works in steep hills.. too..

GAtkins

That is awesome! It makes me hurt just thinking about it. You, sir, are a better man than I.

Glenn

woodcraft

Ha! Last time I did that, Strava showed 1.2 mph, 44 rpm, & 193w. Forgot shoes, 'tho & this was the end of the loop in tennis shoes.

Koyote

BoraxKid : I admire your self-confidence. When everyone - literally everyone – in a conversation is disagreeing with me, I will typically stop and reconsider my position.

But not you.

Kapusta

That 30-34 jump makes a ton of sense at the bottom of the cassette range. It does not feel all that big when you are grinding up a hill. 30-32-34 is a waste of cogs.

Also, going from a 32t big cog to a 34t big cog is no that big of a difference. If you are worried, go with a 36t big cog.

gsa103

That's the maximum heart rate test. Your max heart rate is equal to whatever your heartrate is at the top of that wall, when you hear a car behind you.

Koyote

This sentiment keeps popping up, and for good reason: a 4-tooth jump at that end of the cassette is a relatively small % jump...And anyway, that last cog is basically a bailout gear -- the gear you shift into while murmuring "Sweet Jesus, this is steep!" under your breath. For that, you actually want a decent-sized gap.

kingston 

this megarange cassette has a 10-tooth jump to the last cog.