53/39 or Compact
Comments
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gears are a personal thing ... there are some anti-double fundamentalists on this site I've noticed! "no, you'll never get up a hill with that gear" etc. etc.
I like the 50-36 compact. Campag make them but you might have to phone a shop as they are not always listed on websites, if you are buying that way. Mated to a 11-25 block, I can apply the power at 40+mph (talwind / downhill), and get up 25%+ hills. Done lots of big euru sportifs with this combo.
the nearest double is 53/39 with 12-27, which i have on another bike, but it is heavier, and you end up cross-chaining it more b/c 53 is such a big gear. A 50 tooth ring allows you to keep a failrly straight chainline while still firing up hill.0 -
juggler wrote:
likewise exercised the 53/12 on the way to work today, but maybe that was me trying to prove a point..... mostly a nice long gradual slope for the final couple of kms, turning the gear nicely and getting well over 50 kph... the other side of the hill before that is a different story ... but no need to go near the big cogs, 39 and somewhere near the middle of the cassette is fine...
I hit 40 mph twice a day on my commute.....but I can also grind back up the same hills on a 52/23. I probably shouldn't, I'm just too lazy to change the front ring!!0 -
I'm left a bike in 55x11 for the rest of year just to prove a point.
fortunately i don't ride that bike anymore0 -
It's weird how some people seem to think that a compact necessarily means lower gearing. It will if the cassette is the same, but assuming you are running a 53 chainring with a 12 tooth smallest sprocket, you just need to change to an 11 tooth smallest sprocket to entirely compensate for the change from 53 to 50 biggest chainring (actually a 50-11 is minutely higher than a 53-12, but effectively they are the same gear). A compact can give you some lower gears of course if you can't get a large enough biggest sprocket for your needs with a 39 ring, but IMHO one of the most significant things in deciding between, say, a 50/36 and a 53/39 is not total range of gears but how it will influence the way you use the front shifter. In general, you don't want to be shifting at the front any more than you have to. I use a 50/36 with an 11-23 cassette and on flattish to moderately rolling terrain I am in the big ring nearly all of the time. I only really change down to the small ring for substantial hills or if I am really tired, going into a constant stiff headwind and want to get off the larger sprockets. If I had a 53/39 with the same sprockets I would be changing at the front a lot more I think. On the other hand, I could probably choose a cassette for a 53/39 that would allow me to change at the front exactly as I do now. Both the chainset and the cassette would be physically larger and marginally heavier however (although sprocket and chainring wear would theoretically be slightly less).
An important thing to bear in mind is the difference between the smallest and largest chainring and how this influences the magnitude of the "jump" between the two. Between both 53/39 and 50/36 is 14 teeth, but the standard 50/34 compact has a 16 tooth difference. Surprisingly, the extra 2 teeth do make a significant difference; I find the jump between 50 and 34 annoyingly jarring compared to 50/360 -
Very good post, neeb.
I agree with you on the sixteen tooth gap on the usual compact setup being annoying. I run 50/36 on my best bike and 48/34 on the winter hack.0 -
eh wrote:50-12 @ 110 rpm is 37mph
If you race this it too slow. However, if you just ride for fun etc. it should be more than fine.
In an ideal world you'd change your gear ratios depending on ride, race, course, etc., but most of us can't be bothered with the fuss and so have to compromise.
Race what? You leading out Elite calendar or first cat sprints on a downhill with a tailwind?
I've got a 12-26 on my winter race wheels and 11-26 on my summer ones. Never spun either out properly apart from coming off the top of Port De Bales when I thought 80km/h and 50/11 might be quick enough.
And there's a few Premier Calendar riders who might disagree about compacts not being quick enough. IIRC there's crits that have been won on them in the last few years.0 -
Neeb is spot-on.0
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Comparing 53/39 with 12/25 to 50/34 with 11/23...
On the big chainring, the 53/39 can go down to 12.5mph and the 50/34 can go down to 13mph. This assumes going down to a cadence of 60 and going down to the third largest sprocket.
So change the cassette and you can stay on the big chainring longer on a 53/39 than on a 50/34.
Neeb is right!0
