Conference noted::bicycle

I'm 5'5" (I know you asked for taller riders input...) and I use 170mm cranks 
53 tooth chainrings (52 in the spring).  I've always ridden 170's, and the one 
time I tested a bike with 165's (what some makers think I should be riding) I
wasn't comfortable (there were other reasons as well).

I was a bit surprised that I could stay on top of a 53, but I apparently have 
the power.

The point of this is that shorter cranks and smaller rings are good for spinners
and longer cranks and bigger rings are good for a somewhat lower cadence and 
more power.  (I still spin my setup at 100rpm).

I would think that you'd benefit from longer cranks, given your size.  Do you 
find yourself spun out at times that you'd rather not be?  What cadence do you 
ride?  Do you like to spin or mash gears?  How are your knees?

Kevin

    
    I would think that you'd benefit from longer cranks, given your size.
    Do you find yourself spun out at times that you'd rather not be?  What
    cadence do you ride?  Do you like to spin or mash gears?  How are your 
    knees?
    
    
    I find that I'm most comfortable riding at about 80 rpm and prefer
    pushing a higher gear I therefore find myself as you put it "spun
    out" quite frequently. I have tried to increase my cadence but 
    although I can manage it for a while I always slip back to around
    80. I guess my legs just don't have the required fast muscles. My
    knees caused some problems once during a particularly hilly and
    heavily loaded tour but rest and exercising the "other" muscles
    neglected by cycling cleared the problem. Nobody locally carries
    the longer cranks or a bike equiped with them so I guess if I want
    to try them I'll have to buy them. 
               Thanks for your reply
                                     Rich.
      

    
             Rich, I asked the same question about a year ago in note
    # 1115. The responses seemed to go off on a tangent for the most
    part, but there were a couple of opinions there. I believe it's
    stated that there are other notes which discuss the same thing.
          To update you on what I've done since then, I did take the
    risk myself and change. First I called around to several nationally
    known bike gatalouge sales, they were out of the 172.5's I wanted,
    so I wound up jumping to 175's (Dura-Ace). I just installed them
    about a month ago so I really don't have a significant amount of
    road miles on them yet (maybe 100), and from the indoor trainer
    I don't think I'll get a true picture of how they'll be. I'm not
    particularly tall at 5'11, but I can squat some fairly major
    league weight on the off season (400-500 lbs.) My intent is to 
    try and capitalize on leg strength. Tho it's real early in the 
    season, I have  to say I'm very pleased with the better leverage
    I'm able to put into the pedal. It will be an adjustment learning
    to spin those babies where I'd liketo be, 90-105, but I don't see
    it to be too big of a problem. With some time in the saddle and
    concentrating on keeping the cadence up, I'm sure I'll be there.
    Now to see how much more dog tired I'll be on a century ride 
    remains to be seen....my opinion so far is .....go for it.
    
    Dave
    

    I've read in many places that one should not switch back and forth with
    different crank lengths. This means that if you have several bikes that
    you ride, they should all have the same length cranks (although a 2.5
    mm difference may be too small to notice). Also, if you switch to a
    longer or shorter crank, stay with it. If I recall correctly, the
    reason cited was possible tendon damage. This can also result from
    making a drastic change in the seat height. Generally, though, riders
    over 6' benefit from 175 mm cranks. Keep in mind that 175 mm and 172.5
    mm are not always available in all brands and models.
    
    roger

    To the point of going to bigger crank. I am 6'2 I just move to 175.
    You will have the lever you need to push the big gears. I have A 53
    chain ring now for the spring. but I have a 55 for the summer. I would
    go with the 180 But I need the connering when I race in Crits.
    
    Mike

I believe I've read that the pros (some, all?) will change crank lengths 
depending on the type of event there in: short for crits (for spin) longer for 
road races (esp hilly ones).  Also late in a stage race they may also change.

I think as long as your seat position is adjusted to keep your knee in the same
place relative to the pedal axle you wouldn't have a problem.  Not that I would 
do this.

Kevin

    Thanks for all your advice. After weighing up the pros (possibly
    more leaverage allowing larger chainrings) against the cons (the
    cost of it all) I have decided to purchase either the Shimano Ultegra
    or the Campagnalo Athena chainset with 175cm cranks. If I feel there
    is an improvement in my performance then its either get busy with
    the crank puller or save up to change the chainsets on all four
    bikes. Any advice on which of these two chainsets I should go for.