[crank lenght] Better leverage ??

"le-sheq" (clip) is the leverage benefit big enough to justify extra money
spent on the longer (175) crankset?
^^^^^^^^^^^^^^^^
175/172.5= 1.4% I hardly think you would notice it. It would be equivalent
to half a tooth change on a 34 tooth rear cog. (Please don't tell me you
can't change less than one tooth. ;-)

le-sheq said:

is the leverage benefit big enough to justify extra money spent on the
longer (175) crankset?

Save your money. That 2.5mm difference is extremely tiny, and the
"benefit" even with something much longer (or shorter)might be zero.

Studies on the effect of crank length on performance have not been able
to find any meaningful correlations. Practically all riders can perform
optimally with the standard lengths, unless they are very short.

BTW, this has been discussed many times on this newsgroup... and
recently, too. Do a search if you'd like some light reading...

le-sheq said:

After reading alot about cranks, I still have doubts which lenght is best
for me. I'm around almost 6' tall and my inseam is 86 cm (33.88 inches). Now
I have crank 172,5 mm long. Ocassionally I participate in amateur road races
where the terrain is very hilly, with steep (+10%) climbs. I thought of
swithing to 175 mm crank, which, according to this
http://www.airborne.net/eready/janette/store/sizing_step3.asp is right for
me.

I suspect that Airborne has more 175 cranks to sell, so they say that.
Put 4 people in a room and ask about crank length, get 5 opinions. I
use 172.5 for anybody in your height range. 175s won't make any
appreciable difference. Climbing 10%+ grades is hard for everybody. A
crank 2.5mm longer won't make it any easier, "may" make your knees
complain.

le-sheq said:

After reading alot about cranks, I still have doubts which lenght is best
for me. I'm around almost 6' tall and my inseam is 86 cm (33.88 inches). Now
I have crank 172,5 mm long. Ocassionally I participate in amateur road races
where the terrain is very hilly, with steep (+10%) climbs. I thought of
swithing to 175 mm crank, which, according to this
http://www.airborne.net/eready/janette/store/sizing_step3.asp is right for
me. As a rider, I like low cadences and I'm build more like a sprinter (80
kg) than an up-hiller. I've read that longer crank is useful on uphills

That's widely repeated nonsense.

Quoted message said:

but is the leverage benefit big enough to justify extra money spent on the
longer (175) crankset?

Absolutely not. If you want more "leverage" use a smaller chainring in
front or a larger sprocket in back.

Crank length does affect leverage, but that's not a reason to select a
crank length. Select a crank length for biomechanical reasons.
Especially, if you get sore knees, shorter cranks can sometimes
alleviate the problem.

There would be zero performance advangage from swapping out your crank
to one an eensy bit longer. You would be throwing money away for nothing.

See: http://sheldonbrown.com/cranks for more details on this.

I'm about your height and generally use 165 or 170. Tried 180s but they
made my knees hurt. Tried 150s but I had to set my saddle too high, but
otherwise they were OK.

Sheldon "Cranks" Brown
+--------------------------------------------------+
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| --Don Hebb |
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Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
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