Campagnolo 12-Speed

Discuss light weight issues concerning road bikes & parts.
MiddMan
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by MiddMan

Exactly. So again, I have no qualms with those who don triple cranks. When I was much younger and in my college days I climbed all the gap roads in VT with just a double 53x39 crank and 12-25 nine speed. It was hard, but the mentality back then was sort of like, ‘if you can’t do it: get stronger, use triple, or use mountain bike.’ Could I do that now? I doubt it. But maybe with a 52x36 and 27 cassette I might.

I admit that despite my older and 10kg heavier self, I still push myself to use the double, get stronger, and mostly just have fun 8)

PS Not in one day obviously—although there is a Frodo that does most in a day! I did different gap climbs over the course of a couple summers..
themidge wrote:
Mon Apr 23, 2018 6:39 pm
Yeah, triples are definitely a dying breed, understandably, as they aren't particularly necessary for most riding, not to mention uncool. Shimano used to make a triple all the way up to 105 level (or maybe even ultegra?) but now I don't think you can even get a Tiagra one.
I concur about cassettes shouldn't be bigger than chainrings, serious question here: has anyone reading ever actually needed easier than 1:1? That's a veeery low gear in my book.


jih
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by jih

There’s nothing all that special about a 1:1 ratio, it’s a reasonable gear for staying below threshold on 25% plus climbs. Not something most people will need, but not useless either.

The bike is still geared up from feet to road by the ratio of the crank length to the radius of the wheel.

I quite like how large cassettes look on disc wheel bikes. I think it looks neat if the cassette is about the same size as the rotor.

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Calnago
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by Calnago

jih wrote:I quite like how large cassettes look on disc wheel bikes. I think it looks neat if the cassette is about the same size as the rotor.
The only plus to that scenario is that regardless of which side you look at it from, half the ugliness is hidden by the other.
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c60rider
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by c60rider

Calnago wrote:
Mon Apr 23, 2018 10:05 pm
jih wrote:I quite like how large cassettes look on disc wheel bikes. I think it looks neat if the cassette is about the same size as the rotor.
The only plus to that scenario is that regardless of which side you look at it from, half the ugliness is hidden by the other.
Then you'll need a double disc on the front to even that up. That's what makes them so abominable for me on road bikes the disc on one side of the fork. There's no way of hiding it. And I was joking about the double on the front we'll be over the handlebars every time we touch the brakes :lol:

2lo8
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by 2lo8

jih wrote:
Mon Apr 23, 2018 9:53 pm
There’s nothing all that special about a 1:1 ratio, it’s a reasonable gear for staying below threshold on 25% plus climbs. Not something most people will need, but not useless either.
Assuming 60rpm, that's 7.6kmh, 6+w/kg on 25%. Most people aren't competing in the le tour, so I'd guess a lot more people than you estimate.
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Calnago
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by Calnago

:) The significance of 1:1 gearing is nothing more than it’s a very easily understandable and relatable ratio...that’s all. And the fact that it is a very very low gear for a road bike.
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pdlpsher1
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by pdlpsher1

Gear ratios is a very personalized decision. There are lot of factors that decide the ratio used. I belong to a club with a number of very strong riders. I consider 'strong' as one-hour FTP of 300 watts. Several guys are the 300w riders in the club and they have 11-32 gears! We have a lot of steep hills here and we are at altitude. Personally I'm nowhere near 300w and I find a 11-34 to be indispensible. I welcome a 12-speed cassette. Better yet I welcome a 13-speed cassette as my current 11-34 11-speed cassette is already domed over so in theory the Campy 12 cogs would fit in the space taken by the Shimano's 11 cogs.

Zakalwe
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by Zakalwe

How many long, sustained 25% climbs are there in the world where you need to stay below threshold with a 1:1 ratio?

2lo8
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by 2lo8

Most people aren't over 6w/kg international pros, so that's not really a relevant question to most people.
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Alexandrumarian
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by Alexandrumarian

I wonder if the brakes are compatible with 2015 levers. I'd be tempted if they are more powerful (and they seem to be at least stiffer judging from the geometry)

Zakalwe
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by Zakalwe

Pretty sure I read that they are

Edit - yes, here viewtopic.php?f=3&t=150738&start=345#p1395047
The bike they had set up was a disc-equipped bike though I was more interested in the brake calipers. They will work with existing 11 speed kit for those that need a brake with more clearance. As for the cables the new Maximum Smoothness cables are backwards comp

wingguy
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by wingguy

themidge wrote:
Mon Apr 23, 2018 6:39 pm
serious question here: has anyone reading ever actually needed easier than 1:1?
“Need” is basically irrelevant when talking about gears. No one here “needs” the gears they’ve got - pretty much everyone could ride pretty much anything with tougher gears than they normally use. The question is whether lower gears are helpful.

When Mountains were first introduced I to the Tour with the Tourmalet they had to climb it with nothing more than a flip flop hub - give any one of those guys who made it over a modern cassette and chainrings and they’d have crushed the field.

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themidge
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by themidge

Yeah, I should have been more clear about 'need', 'helpful' is better. My question still stands though, some people seem to put such low gears on their bikes I struggle to see how they could ever need/prefer them, regardless of fitness.
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2lo8
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by 2lo8

themidge wrote:
Tue Apr 24, 2018 8:59 pm
Yeah, I should have been more clear about 'need', 'helpful' is better. My question still stands though, some people seem to put such low gears on their bikes I struggle to see how they could ever need/prefer them, regardless of fitness.
It's really simple:
10% grade or more
70 rpm or more
FT or less
3w/kg or less

If a cyclist has half the w/kg as a pro, then they would probably find the same gear useful on slopes half the grade. These people are also relatively less adapted to make anaerobic efforts, mash through things, and not skin and bones which hurts their w/kg, I know lots of people here are very strong capable riders who dedicate their life to cycling, especially since dropping $10k+ on a bike is not unusual here. I don't mean to offend but it is a little mind boggling how much people can be unaware that there are many, indeed most cyclists, are considerably weaker than them and also do not make their life revolve around bicycles or training, even certain kinds of people that buy super record (because they can).

I also personally have great difficulty turning 39x25 on 20% without momentum carrying me through. I beleive is not just an issue of fitness, but also has to do with the way steep grades interact with pedaling using gravity, in other words, climbing by standing on pedals, not climbing by pulling on the bars.

If you plot out:
sin(2pix/d)*c+gx
sin(2pix/d+pi)*c+gx (for the other side of the crank)
where:
d = meters of development
c = crank length in meters(165mm: c=0.165)
g = grade (20%: g=0.20)

Let us do some common sense checks to make sure the plot is accurate. d=5, c=0.170, g=0.00. It takes 5 units of x for one complete cycle, y tops out at 0.170, and -0.170, so far so good. d=5, c=0.000(tracking bb axle), g=0.20. When x=5, y=1. That seems reasonable, 1m rise over 5m run is 20%. Any engineers are free to correct me if I made a mistake.

Let us qualify dead zone where the slope for both plots is 0 or positive. At 0%, the only dead zones are TDC.

For me on 39x25 on 25mm on 20% is:
sin(2pix/3.29)*0.165+0.20x/100

1 full sin cycle is 3.29m. Between x=0 and x=3.29, slope is equal to 0 at (1.183, 0.364) and (2.107, 0.294). Note that there is a negative slope between these two points, meaning the pedal is traveling downwards.

The difference between y values, the distance the pedal moves downwards in one sin cycle, 0.364-0.294=0.070. Only 70mm, compare this to 0% grade where the pedal would be moving downwards 330mm. That is quite a large difference. Remember that work = force (gravity in this case) * distance.

Let us also consider the parts where both plots have positive slope, in other words, both pedals are moving upwards. I'm just going to cheat here and double the value I get from my previous 2 points 2(2.107-1.183)=1.848. This is the x range that one of the pedals is moving down. 1.848/3.29 = 0.5617. Only 56.2% of crank rotation has a pedal moving down. 43.8% of crank rotation or forward movement, both pedals are moving up. 43.8% of standing on the pedals dead zone.

Doing the same analysis with 34x32:
sin(2pix/2.24)*0.165+0.20x/100
Gives us the points (0.719, 0.293) and (1.521, 0.155). The pedal moves down 138mm, nearly twice as much as 39x25. 71.6% of crank rotation or forward movement has one of the pedals moving down. Only 23.4% is standing on the pedals dead zone.

This second component has absolutely nothing to do with fitness, except that you can compensate for it by pulling on the bars. I am curious what effect an oval chainring might have on these figures, but I am in no mood at the moment to attempt calculation, or create a spreadsheet for every gear combination until I have some time to check my math again. I may have fudged the numbers somewhere, but I beleive this is correct in principle. Note that longer cranks would help, indeed because of more leverage as people have said in the past. I remember one time trying different gears on the same short climb from a stop at the bottom, and there was a point where it seemed like the pedal was actually pushing me back when I tried to stand on the pedal.
Last edited by 2lo8 on Tue Apr 24, 2018 11:52 pm, edited 1 time in total.
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themidge
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by themidge

Fair enough, maths is the answer! :D
I can appreciate that people's cycling abilities vary greatly, although I haven't spent 10k on my bike. Obviously some people do need/want very easy gears, after all, we've all seen a MAMIL grinding up a hill, haven't we.
I think my grievance is with the current (and future) state of affairs in the industry, which seems to be pushing all this 1x, super low geared, decidedly un-race-like stuff, which many people (especially on this site) don't want or need.
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