crankset length

Discussion in 'Cycling Equipment' started by wangatang, Feb 9, 2005.

  1. wangatang

    wangatang New Member

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    I bought an aero seatpost for my specialized S-works E5 frame and I'm afraid that it might be too long because of the aero part. Should I get a shorter 165mm crankset to compensate or get a regular 170mm and just get a different seatpost? Is there any downside to a shorter crankset. I'm a shorter rider 5'5" so i'm not sure which way to go with the crank. Another question, is there any advantage from a double to a triple? aside from getting more gear combos for climbs. Is the weight difference significant? and what is the main quality difference between an ultegra crank and a 105 crank? please help... Thanks
     
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  2. Doctor Morbius

    Doctor Morbius New Member

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    If it were me, I'd get the crank length that best fit your leg length and cadence style.


    The downside to a shorter crank is less leverage to the pedals. Shorter cranks are sometimes used by riders who prefer a high cadence, i.e. spinners.


    Tripple cranksets are usually marketed to the more casual rider as they do add some weight and some of the gear combinations are redundant. Except for the MTB crowd, I've never seen the pro's use them.

    If you live or ride in a hilly area then you could get a tripple to help with those hills until you get conditioned enough to tackle them on the middle ring. You could also use a double crankset with different gearing on the rear cassette. It all depends on what type of rider you are and what is important to you. If you're into saving some weight and shaving grams, then go with a double up front and get a cassette with larger cogs for hills and get a second cassette for riding on the flats. If you live and/or ride in a flat part of the country there is no need for a tripple.


    It is to some, especially if they already have a pretty low percentage of bodyfat. Climbing hills fast requres a good power to weight ratio and since you're carrying that bike up the hill it becomes part of the equation. The best bang for the buck when it comes to weight savings is in the wheels and tires. Shaving grams off of your rotational weight will make the biggest difference.


    There are now two types of Ultegra cranks - the newer integrated and the older Octalink that uses a seperate bottom bracket.

    I recently purchased a set of each, a 172.5mm non-integrated Ultegra 9-speed Octalink and a 175mm 105 9-speed Octalink. Both polished, of course (I hate the painted 105 stuff). I haven't installed either of them so I can't comment on whether one is stiffer (better power transfer) than the other. However, just holding one in each hand I can't tell any difference between their weight. They both appear to be very well made.

    I would expect the 105's to be available in an integrated version pretty soon as the Deore grade integrated cranks are already available.
     
  3. dhk

    dhk New Member

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    Agree that if you live in the flatlands, a triple isn't necessary. I rode a double with 39/23 low for many years in the midwest, but it didn't take long after moving here that I realized a triple was what I needed. For those of us who live in the mountains, it's not something just for beginners, until we "get used to the middle ring".

    The fact that Lance and the pro's can race up 8-10% grades in 39/23 at 14 mph has nothing to do with what us mere mortals need. I have about 1/2 his sustained power output (on a good day), so I need a gear a lot lower than his to maintain good cadence on a long climb. My triple has a 30/25 low, and on the 15-20% pitches, I could use lower gearing still.

    Believe the weight difference between a double and triple is around 150 grams, maybe 200 grams max, but that's running the same rear cassette. If you go to a 12-34 XTR cassette and RD with a double, you've probably eaten up a lot of the weight savings anyway....a 34 rear cog alone weighs more than a 30 inner chainring.

    No need to just stay with Shimano either. I use the FSA Team Carbon triple crank with Ti ISIS integrated BB, which may be lighter than the Ultegra double setup with the cartridge BB. At any rate, wouldn't let a few grams determine what gearing to run for best performance.
     
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