Road Cycling Essentials

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I don't understand all this gear ratio nonsense, or more specifically the supposed maximum speed depending on setup and cadence. If I choose my setup which is (at the moment) 50/34 - 11/32 which 172.5mm crank it shows the max speed even at 120rpm cadence to be 41.5mph. I've gone considerably faster than that, going downhill of course. Does this supposed maximum mean what is possible on say the flat? :confused:
 
R0B75 said:
I don't understand all this gear ratio nonsense, or more specifically the supposed maximum speed depending on setup and cadence. If I choose my setup which is (at the moment) 50/34 - 11/32 which 172.5mm crank it shows the max speed even at 120rpm cadence to be 41.5mph. I've gone considerably faster than that, going downhill of course. Does this supposed maximum mean what is possible on say the flat? :confused:
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Its not maximum speed. It's the speed you will be doing at a fixed cadence.
In your example, if you pedal at 120rpm, you'll be going exactly 41.5mph. If you pedal faster, you'll go faster. If you pedal slower, you'll go slower.
 
Russinating said:
Of course it does :p. You could be going 41.5mph with 0 cadence down a hill...

Or pedalling like a man berserk.
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touch said:
Its not maximum speed. It's the speed you will be doing at a fixed cadence.
In your example, if you pedal at 120rpm, you'll be going exactly 41.5mph. If you pedal faster, you'll go faster. If you pedal slower, you'll go slower.
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Great, thanks. Sometimes we (I) need it spelling out in simpleton language :D
 
Russinating said:
And you don't find the gaps too big (esp. after coming from a 12-25)?
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Not for me, to be honest i haven't really noticed the gaps being any bigger. The benefit of being able to smash it in the 11 and then keep going hard in the 28 when you get to a really steep hill far out weights any negative with gaps in the gears.

Also as soon as i moved to 11-28 i started setting much faster times on Strava

Only downside is i now was 11-28 on all my bikes:D
 
Going downhill you have to assume you're also doing some some freewheeling. On a fixed wheel bike there would be a definite max speed (ignoring things like air resistance) related to the gearing and wheel size.

Edit: Too slow...
 
Kimi said:
Not for me, to be honest i haven't really noticed the gaps being any bigger. The benefit of being able to smash it in the 11 and then keep going hard in the 28 when you get to a really steep hill far out weights any negative with gaps in the gears.

Also as soon as i moved to 11-28 i started setting much faster times on Strava

Only downside is i now was 11-28 on all my bikes:D
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Robzere31 said:
Me to, although I think losing nearly 2kg from the weight of the bike helped as well, along with replacing the 2 1/2 year old 2300 groupset with something a little better :D
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Sold :). Grabbing the Ultegra now.
 
Looking at that gear calculator this 11-32 the canyon came with is going to be insanely gappy. I definitely reckon I'll be swapping it for something a bit more sensible. I'll stick it back on if I know I'll be scaling any alpine ascents but I reckon an 11-28 will more than do me. Especially considering the 2 tooth smaller little ring the canyon has over my CX that has a 12-27 cassette.

Edit: Check that weather out for this weekend Manchester peeps! Definitely decent riding weather.
 
[Damien];24370192 said:
Haha, you lunatic! I reckon trying to climb some of the hills near us with an 11-23 would end up in blown knees or snapped cranks. One of the two.
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Nonsense! Rule number 5 ;) I wouldn't recommend a 11-23 on standard cranks but I find 11-23 enough on a compact, but our toughest hills are relatively short but can be quite steep.
 
Rusty_Noob said:
Nonsense! Rule number 5 ;) I wouldn't recommend a 11-23 on standard cranks but I find 11-23 enough on a compact, but our toughest hills are relatively short but can be quite steep.
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I think my knees would simply crumble if I tried to use an 11-23 :eek: I'm hoping to try Winnats Pass tomorrow and I think I'll struggle even on 11-32! Its about the steepest hill I know of around here so if I manage it OK I may consider an 11-28 when my 11-32 needs replacing.
 
Went from a 12-25 to a 12-27 and the difference is just right for me, gives the same spread as the 12-25 in the meat of the cassette with the 23-25 on the 12-25 changed to a 24-27 on the 12-27. I find I dont use the 27 that much but the 24 seems quite a good compromise over the 23 or 25.
Not tried an 11-28 but i cant see me wanting an 11 speed cog anytime soon, i'm happy enough with the 12 on my 50-34, i'm not one for really high speeds anyway....40mph is fast enough for me.
 
Rusty_Noob said:
Nonsense! Rule number 5 ;) I wouldn't recommend a 11-23 on standard cranks but I find 11-23 enough on a compact, but our toughest hills are relatively short but can be quite steep.
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How steep is 'steep' over there though? ;)

If you can climb some of our 25% monsters on a 23 cog then I might as well just hang up my bike because there's no hope of ever competing.
 
I've no idea unfortunately, I know some sections of the Val Des Terres (which is used as a national hill climb circuit) is greater than 15% in places - but that's not one of our steep hills. As I say though they're short, Val Des Terres is only 0.5 miles.
 
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