Triple vs Compact crankset

Discussion in 'Cycling Equipment' started by Andrepaul, Sep 28, 2005.

  1. Brothrmark

    Brothrmark New Member

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    I tried an experiment this weekend. I swapped the outer and middle rings of my triple [52/42] with the biopace rings [50/40] from my old double. I locked out the granny gear altogether. After some adjustment for trimming etc; here's what I know...

    It was like upgrading my tiagra shifters to Ult or DA. Crisp, no nonsense shifts. I rode several miles of "Jamestown Pave" [brick roads] and some of our adirondack foothills. I'd be halfway up a long hill thinking "this was a mistake" and look down to realize I still on the big ring. I'd move to the small ring and fly the rest of the way. I did that three or four times. It was my best ride this year.

    I suppose I should look at swapping the crank, BB, and all eventually, but this was so sweet. I really am a fan of the biopace rings. They were on the bike when I bought it used, and I ran them for a full season before I even knew what they were. The 50/40 is super combo. I think 40 is the smallest BP ring made in the 130 bcd.

    My suggestion would be to try new rings first if you have some mechanical know-how. It was pretty easy to do, and rings can be purchased on ebay for half their retail price.
     


  2. Andrepaul

    Andrepaul New Member

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    Thanks to everyone regarding triple vs double compact cranksets...I took the plunge and went with a Campy Chorus Carbon Compact and I'm finding that it suits me fine compared to the triple. In other words I have enough gear choices to help me on the flats as well as on steep climbs.
     
  3. RPatterson

    RPatterson New Member

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    You can first run the numbers, by looking up the gearing ratios of the two different candidate setups, on a gearing chart. This will give you a chance to make logical comparisons, and consider the pluses and minuses. You can chart the distribution of ratios for each of the setups and compare them, side by side. It will be helpful to think about the setups you've used most often in the past, as well as whatever you're currently riding. You will be attempting to basically choose between the compactness & minutely simpler operation of the double ring, or the closer ratios & wider range of the triple. It may be that if you need some lower gears to go easy on your knees,you might prefer the triple, but that is depending again on the comparison chart. You may not really need so many close ratios. If you choose the triple, I feel that you won't be hammering away on the big ring all that much, and the double gives you a smaller big ring. I don't happen to know much about the new wave of double-ring setups, except perhaps as a marketing move intended to offer a plausible alternative to triple setups. If these "new" doubles are available with fewer teeth as an option, you'd have more gear-ratio comparisons to sort out. I roadraced in my thirties until I blew out a knee, and I'm in my 60's, so we may be sharing many of the same concerns. If I decided to run the double, I'd see if I could get maybe a 30-tooth or smaller front ring, and a 48-tooth for the large, which is typical of an old-school mountain bike triple's big ring, and the older compact mountain triples were usually 44-tooth big rings, which might also be large enough. Then I'd go with large-ish rear cogs, with the largest being at least 32 or 34 teeth and the smallest at around 13 or 14 teeth. Even when in my prime, I didn't spend a lot of time flying down roads on my big ring, and I had almost always wished for a smaller one when I did use it. I'd be looking to use a 44-tooth for the big ring on a double. I'd stay with the same sizes on the rear for either setup. I'm guessing that you and I likely would have little use for highest gears of the Chorus, they're for fast downhills and closing sprints. One of the main ideas to emphasize is to see that the largest rear cog is larger than the smallest ring on the front. Before you can decide, however, you have to make a good assessment of the road conditions wherever you intend to do most of your riding, what types of rides you intend to go on, and what types of bike buddies you intend to go riding with. Do you have to ride uphill a lot? Are you going to commute with it? Are you looking to improve your fitness? Are you going to encounter any hills? Do you ever try to ride at high speed? Do you shift as often as is practical, and adjust your speed when conditions change, or do you tend to stay in one or two gears most of the time? Hopefully, when you answer these questions, you will have a way to progress considerably towards making the choice. Based on the most obvious difference between the two setups, the decision will depend on whether you can deal with larger jumps between gears on a double, and whether you can get at least one ultra low gear on either setup (critical for climbs, the bike will gather rust at home if it kills you every day on that hill down the street). Even without having had a chance to try a new double setup, I have to confess that I don't see too many practical advantages to using it, compared to a triple. There are numerous examples of attempts to reinvent bike parts, from decades of bike refinement, that exemplify the phrase, "Worked so good, it had to go!".... With that phrase in mind, I admit I am having some difficulty gathering a list of good reasons to believe that a double is any real improvement over a triple, at least perhaps for everybody who doesn't race. Both setups still need two shifters, two derailleurs, and two cable runs, and you will still need to be able to "trim" the derailleurs as you shift. If the industry is trying to "dumb down" the entire matter of shifting gears, this method of doing so isn't really making much of a dent in any of those aspects! At best, the only advantage to be gained by having a double crank setup would come by way of saving a few ounces of reciprocating mass at the crank, plus a small decrease in wind resistance.. But you will wear out chains and teeth faster, and you will have to clean & maintain almost all the same components as you would with a triple, too. About all they've accomplished by undertaking this development effort is to have taken an old-school double crank design, and slightly modified it to carry smaller chainrings, as a way to trim production costs. When most of us had to settle for nothing but doubles in the old days, we didn't wish for smaller rings. We wished for triples!! We were very pleased when triples became popular, and we could finally obtain them! At this point, I'm about ready to vow to use a triple for the rest of my life, as a statement to the industry. Gee, next thing you know, they'll be going back to clips & straps. And leather helmets. In fact, IMHO, the industry might be hoping that we will all think they are giving us something more, by taking something away. Since I haven't seen these new components, I haven't looked at prices, but I'll predict that we're not going to be enjoying any significant price cuts. Remember, these new double cranks are "better", and so we have to pay more for them!! Do you recall spring-loaded seatposts, and Biopace rings? At least those offerings were clearly intended to enhance our riding, and in fact a lot of us still like to use a Biopace on the granny ring. I'm sorry for being so wordy, but I hope that I've given you a few helpful ideas. Just remember (another old phrase): It ain't the bike, it's the rider!
     
  4. oldbobcat

    oldbobcat Well-Known Member

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    I think this issue was resolved almost 9 years ago, Patterson. But thanks for the tips.
     
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