39 x 25T

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PoorCyclist
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by PoorCyclist

Does anyone use this chainring and cassette combo?

I found it difficult to climb when grades exceed 12%, maybe it's a technique thing, the grade pitches up to 16% and it was pure torture. I was going so slow and was fairly sure it went faster with a compact.

HillRPete
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by HillRPete

16% on that sounds like torture indeed. Around here most people are running 34x27 to cope with those gradients up to 20%. Also it's nice to spin uphill, at least in training :D

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stella-azzurra
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by stella-azzurra

A. You need some fitness build up so get fit on the 10% or less grades first
B. Here is a gear calculator to help you determine the best gear vs rpm vs speed http://www.gear-calculator.com/#
C. Good luck!
I never took drugs to improve my performance at any time. I will be willing to stick my finger into a polygraph test if anyone with big media pull wants to take issue. If you buy a signed poster now it will not be tarnished later. --Graeme Obree

hansonator69
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by hansonator69

I run 39x23. :wink:
Slam your stem.

wingguy
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by wingguy

PoorCyclist wrote:Does anyone use this chainring and cassette combo?

I found it difficult to climb when grades exceed 12%, maybe it's a technique thing, the grade pitches up to 16% and it was pure torture. I was going so slow and was fairly sure it went faster with a compact.


It's not technique, it's just a big gear. I use a 39x25 in an area with quite a few climbs peaking at 20 - 25%, loads peaking at +15% and a few that average 10%+. Quite frankly though, it's not big and it's not clever, it just makes it a damn sight harder and slower overall than it should be! I can't be bothered to spend any more on this one, but my next bike will have different ratios.

eric
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by eric

We are lucky to have a lot of big and/or steep climbs in California. Get a compact if you want to enjoy them. You can shift to a higher gear if it doesn't hurt enough.

Gregorio
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by Gregorio

That is what I use. I like to climb. There are some 20+% grades around here but they are relatively short. 1/3 of a mile or so.

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Juanmoretime
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by Juanmoretime

39 X 25 is my bailout and when I will be climbing the 11-25 goes on. You are supposed to suffer in the climbs. :shock: :D
RESIDENT GRUMPY OLD MAN.

ticou
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by ticou

I can climb a short 12% on the 50, but it better be short! I love my compact, and one day I'l use my 34/29, i just knows it.

What was that Village People song? Macho macho maaaan, I wanna beee, a macho man

rustychain
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by rustychain

You will be able to climb faster with less fatique using proper climbing gears. Using to steep a gear will just kill your legs. I have a road I climb several times a year, after a increasing grade for the first five miles you hit a sustained grade of 20 percent for two miles with it hitting 24 percent for about a half mile of that and the piss poor road surface just makes it harder. I have done it with a 39x25 and frankly it killed me. My best time was with a 34x29 and I had the legs to climb over the pass three more times that day (118 miles total miles that day). I have found a 12x29 with a 52x36 chainring a great choice for most big climb days. On flats or rollers I do like a 11x23 with a 52x36, not bad but I need to be able to spin a bit faster in a sprint. Look at the gearing in the Giro mountain stages, climbing gears rule!
WW Velocipedist Gargantuan

Gregorio
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by Gregorio

Rusty...that hill sounds awesome. Must be a strava segment. Compact sounds like a good choice for that one. Where is that?

ticou
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by ticou

rustychain wrote:You will be able to climb faster with less fatique using proper climbing gears. Using to steep a gear will just kill your legs. I have a road I climb several times a year, after a increasing grade for the first five miles you hit a sustained grade of 20 percent for two miles with it hitting 24 percent for about a half mile of that and the piss poor road surface just makes it harder. I have done it with a 39x25 and frankly it killed me. My best time was with a 34x29 and I had the legs to climb over the pass three more times that day (118 miles total miles that day). I have found a 12x29 with a 52x36 chainring a great choice for most big climb days. On flats or rollers I do like a 11x23 with a 52x36, not bad but I need to be able to spin a bit faster in a sprint. Look at the gearing in the Giro mountain stages, climbing gears rule!


Thanks for that; nothing like 24% round my neck of the woods sadly, but nice also to know that the 29 can cope if ever called upon.

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slyboots
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Location: Russia, Moscow

by slyboots

Just a small reality check. ;)

Here is how Pros ride up Angliru, where the steepest 6 km (less than 4 miles) average a whooping 13,1%:
http://www.youtube.com/watch?v=ulViOm2P ... ure=relmfu

And gearing they used:
Juanjo Cobo rode 34×32
Nibali 34×29
Kessiakoff 34×28
Fuglsang and Mollema 36×28
Bradley Wiggins and Chris Froome 38×32 asymmetrical front chain

Of course our own WW members, who regularly conquer multi-mile 20% climbs, would have flown up that Spanish hill...

wingguy
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by wingguy

rustychain wrote:I have a road I climb several times a year, after a increasing grade for the first five miles you hit a sustained grade of 20 percent for two miles with it hitting 24 percent for about a half mile of that and the piss poor road surface just makes it harder.


What is the total elevation gain of the climb, and can you post a graph from one of the mapping sites?

For comparison, this is Monte Zoncolan.

Image

ticou
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by ticou

You would have thunk Bradder's and Froome's DS would have made the mild suggestion to actually recce the most crucial, race deciding climb ahead of last years Vuelta....

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