Crank length thoughts

swampy1970

So, whilst I was pondering my navel and picking fluff out of the ol' belly button whilst watching a chick flick, I started to thinking about the age old debate on crank length and started wondering why longer cranks aren't used by larger riders. With many smaller riders using 175mm cranks without a hitch it's suprising really to me that riders with a 6 inch longer inside leg are often thought of as going to far in using 185mm cranks that are a mere 0.4" longer...

Comments?

sogood

Please concentrate on your chick flick!

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Peter@vecchios

Put 3 people in a room and ask about crank lengths and get 4 opinions.
What works for a rider is what works and changing a crank to something longer or shorter really makes little difference. The only reason to change a length is for some diagnosed injury related change recommended by a competent fit guy, IMO.

geoinmillbrook

Last thought I had about crank length was while standing at the urinal in a public men's room. The water seemed to be deep, and kinda cold.

Sorry I could not resist.

Pretty lame

I know

I am bored

oldbobcat

Eddy used 175s. By most standards 175 is large. Eddy is large. I am large. What's good enough for Eddy is good enough for me.

swampy1970

Why did Eddy use 175mm? Was that all the mechanic had in the team van?

... if it was good enough for Eddy, do you ride on a steel frame with a 5 speed block and oldschool brake cables poking through the top of the brake levers? Clips and straps maybe?

Indurain has been "said" by some to have used custom made Campagnolo 190mm cranks. Sosenka used 190mm on the track for the hour record. Neither were exactly what you'd call "slow" by any standard...

mikesbytes

If you want to spin use shorter cranks, if you want to mash use longer cranks

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oldbobcat

Aw, hell, I just defer to what Peter says. He's got the most experience and his shop always has whatever I need to keep my old steel bikes rolling.

But this forum has been through this several times ad nauseum and most of us, in our myriad little ways, came to the same basic conclusion. I'm outta here.

Peter@vecchios

Glad to hear it and I ride steel bikes as well. In about 2 weeks, come by and see my new Waterford R-32. Polished lugs(of course!!), Reynolds 953 stainless tubes, Steel fork(of course) with my 1986 C-Record/Delta gruppo on it.

geoinmillbrook

+1 or 2 , I use shorter cranks on my cyclocross bike..
tis nothing more than a lever arm. Do have to be aware of fitting however - don't want to damage the knee. May have to move seat and stem to adjust.

531Aussie

i meant to post this last week, but........................

I have a theory that one reason why many shorter riders are shit and pissweak on the flats is because that they use cranks that are too long. They just get used to 170mm+ cranks coz they come standard with very small bikes, so they persist with them, even though these cranks might be too long.

I reckon it's a farkin joke that some 5ft2/5ft3 guys (and shorter) are trying to push 170s, 172.5s and 175s on flat roads, with their feet coming up to their chins at the top of the pedal stroke. I'm 6ft with long legs, and I don't like pushing any longer than 172.5/175 while I'm on the seat.

I reckon the whole issue of shorter guys using too long cranks get overlooked, because they get away with it on hills, due to their power to weight ratio winning every time, inspite of their stupid crank length.

165s, or shorter, should come standard with small bikes.


Anyway, going any longer than 180/185, especially for guys with big feet, presents issues with heels whacking the rear derailleur (and knocking the gears out), if not the chain-stays, so custom frames have to be considered. I even know of guys with big feet having problams hitting the rear derailleur, even with 175s!!

Phill P

I have a nice white mark on my red chain stays where my right heal rubs the chain stay at times (and a nick in my shoes from the same contact)

I must ride slightly heal in on the rRHS but not on the left.

However the point I'm getting to is I ride 175s (6'2/187 long legged) but I don't think I have only large feet (size 10/42?) and have clearance issues to the chain stay, luckily not the rear D.

If I ever went to 180s, that isue would be far worse.

I guess this is one of the reasons Lenard Zinn makes bikes for tall guys so he can spec them with narrow and long chain stays, slack seat tubes, higher bottom brackets, and super tall head tubes.

What 531 forgot to mention about smaller riders and shorter cranks, is that it helps fix the toe overlap issue that short rider often get.

Would be interesting to check knee rise vs hip or seat height. Then a simple rule of thumb would be if you knees get to "x" from you hip height then your cranks are too long for you legs.

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531Aussie

Ha! I also have marks on my stays, but that's coz I ride with my heels in (toes out). I ride 43s, and I don't think that's big. I had to get rid of a Cinelli frame because of the shape of the stays.

I'm 182cm with long legs (89.5cm inseam). I tried 180s for about a year when I was obsessed with this issue, but didn't really have any extra problems hitting the stays, however, I ended up feeling a bit uncomfortable with them for other reasons. Like I hinted at above, I found it harder to push through most of the down-stroke because my feet were coming up too high at the top of the stroke, which is obviously compounded by having to drop the seat for the extra length. I had some rides where I kept getting off the saddle, due to my frustration at not being able to 'get on top of' the pedals to pound the crap out them. I also felt like I kinda had to reach forward. The day I went back to 175s I felt like Superman, so I went a step further and bought 172.5s. I'm definitely no slower with shorter cranks. The only time I miss my long cranks is when I'm off the saddle stomping over short hills, so I bought some 177.5s, but I hardly use them




Without getting into knee height vs saddle height (or, hip angle, I guess), I reckon, even though the 'percentage of inseam' method may not be the be-all and end-all of determing crank length, it's ridiculous that some shorter guys are using cranks which are 23%+ of their inside leg! I can't imagine it. That's like me using 205mm cranks!


Anyway, on the whole long crank issue (which I reckon is way overrated -- sometimes by me ), despite the increased availability of extra lengths, no pro, over about 5ft9", is riding cranks which match Zinn's recommended method, yet they're still smashing amazing times. Some guys are using 177.5s (Ulrich, Backstedt, and Boonen, I think), and we all know about Indurain using 180s and 190s for some time-trials, but they're all tall guys, with the exception of Ullrich, but I'd be amazed if 177.5 was anywhere near 21.6% on his inseam.

One of the 'infamous' long crank advocates says the main reason pros don't ride very long cranks is because of stubborness and tradition, but I don't buy it.


People usually only talk about spin/cadence and leverage when they speak about long cranks, but, in my opinion, the biggest impact long cranks have is on position.

RAH!!