shelbyfv

To be fair the bikes have gotten nicer. A few more tries and we may have a keeper. Not much progress regarding fit, don't know why it has to be so difficult.

mstateglfr 

Zinn is a smart dude, I dont think anyone here would argue otherwise. There are no hard firm rules for fit though and what he has found to work for him doesnt make it gospel. Same for Rivendell and their PBH algorithm, KOPS, and whatever LeMond's algorithm is. There are multiple fit styles for a reason- none are fully right for all.

As for Zinn specifically, I dont need a 200mm crank arm. I just dont. I have no need or interest in one, and that is on the low end of what you say the Zinn method shows I should have so I for sure dont want one thats even longer yet still in the range of the Zinn recommendation.

I have 170mm cranks, 172.5mm cranks, 175mm cranks, and even a 180mm crank. The 180mm is on my least used drop bar bike and I used it since I had it and wanted to see if I liked it. Ends up I cant really tell at best and mildly dislike it at worst. Tough to say what is real and what is imagined due to knowing Im riding something different.
Ive ridden thousands of miles each year with 170mm, 172.5mm, and 175mm crank arms on my bikes due to simply not feeling like paying for crank arms that are all the same length. 0 negative effect on my body or riding in spite of apparently using crank arms that are 3cm shorter than Zinn recommends.

Eric F 

So, because the article doesn't have one specific piece of information you want, you're going to ignore the whole thing? Oy.

As has been mentioned, there are lots of different ways to determine crank arm length, and your inseam length is not way out of the range of usual. When considering options, I tend to look at what the best in the world are doing, how they are doing it, and what they use. I would bet a medium sum of money that zero riders in the World Tour are using 190mm cranks. Not even the tall guys.

Your stubborn refusal to accept any information that doesn't justify your own conclusions is likely going to cause you more problems in your progress as a cyclist. Good luck with that, drippy.

Koyote

Is he actually buying these bikes, or finding them in dumpsters?

Reynolds 

My road bike has 170, my MTB 175 and my hybrid 165 (because I built it from used parts and that's what I had at the moment). I must be very insensitive, because I can't feel any differences.

shelbyfv

Looks as if Moisty has a bike fit soul mate. https://www.bikeforums.net/classic-v...l#post21962159

Germany_chris

That guy KNOW'S but moisture here is still learning.

Eric F 

I can feel a difference between the 170s on my '77 Nishiki and the 172.5s on my other road bikes when I first get on it, but that feeling of it being different doesn't last very long. I've always been pretty sensitive to small positional changes on my bikes, and getting a new bike sorted out to feel "right" can take a while. That's just me.

Moisture

How useful is that link without mentioning inseam? Come on now. I read through the whole thing. They concluded that crank arm length is mostly a fit thing which I agree with. But what is it supposed to fit with. Your legs, right? This isn't the only factor to consider, but it certainly is a good starting point.

mstateglfr

On a regular bottom bracket height, I really wouldn't want anything past 190mm at the very max for pedal strike clearance anyways. But you can't knock it until you try it! I guarantee you'd be extremely happy with correctly proportioned crank arm lengths.

At the very least, I wouldn't be conclusive until you give it a fair try. It undoubtedly the best decision I ever made within the world of cycling and I would not hesitate to do it again.

I've gathered that with my current crank arms, there are zero penalties in over exaggerated range of motion which may compromise an efficient pedalling cadence. If I went any further than the upper limit of what Zinn recommended (2.18x inseam in CM,) I think this would be problematic. But going too small can be equally so unless you ride very casually.

To conclude, I find that Zinn's calculation is actually quite accurate, and is very good as a starting point. from that point onwards, its purely up to you to decide based on experimentation whatever works optimally.

I'd look into the KHS Flyte 747 which comes stock with 200mm ANDEL crank arms. I assure youd be exceedingly happy with the performance.

PS. I got up to roughly 97 revolutions during a brief mild incline yesterday. I wouldn't of been able to coordinate myself spinning like this with my old 165,170 or 175mm crank arms even with toe cages
.

Eric F 

Clearly, you missed the point. With willful intent, no doubt.

Your conclusion is flat-out wrong. In the short term, you're compromising endurance. In the long term, you're very likely compromising the health of your joints - especially your knees.

Also flat-out wrong. Track cyclists typically use short cranks. Some of those guys and gals put out a LOT more power than you or I ever will.

I hit a max of 135 on a ride recently without even realizing it until I looked at my data after the ride. Rolling along for extended periods at 95-100 isn't difficult at all. It doesn't take a lot of practice to be able to do this. You're trying to convince yourself that you can move through a greater range of motion across multiple joints with higher frequency than you can with a shorter range of motion. 100% drippy bull$#!+.

Moisture

You still didn't tell me how you know my crank arms are too long.

Rage

Best take care when approaching the event horizon of a black hole lest ye be pulled in.

Eric F 

Yes, I did, but it really doesn't matter. You - very clearly - aren't going to be swayed from your own misguided conclusions, no matter what anyone says. As I've said before...good luck with that, drippy.

Koyote

Are you familiar with the quote attributed to Mark Twain? "Never argue with stupid people. They will drag you down to their level and beat you with experience."

shelbyfv

C&V was once a bastion of sanity....

Koyote

And then it got all wet.

As far as the bike goes, I don't think the crankarm length is what's holding back old Moisty. That's sort of like the 500 pound guy who wonders if his moustache is the reason why women aren't interested in him.

Germany_chris

There are a lot of penalties to longer cranks with “an exaggerated range of motion” there’s been half a dozen university studies done on it since the 90’s.

you make the same power all the way down to 130-140 so that’s not a real argument either.

if you comfortable and it doesn’t make your knees hurt that really all the justification you need

Eric F 

Ahhh...yes. Thank you for reminding me.

Eric F 

I have serious concerns about the long-term effects on the knees. Just because it feels okay now doesn't mean it will continue to do so. On that topic, there was a thread in the "50+" section with people talking about how switching to shorter cranks relieved issues with knee pain. We all feel bulletproof when we're young.

Reynolds 

Somehow this discussion reminds me of the guy who found how to make bikes faster - using a taller gear, like a 60/11!

Moisture

I specifically changed my crankset because I was beginning to experience knee pain with the 175mm crank arms I was using. I always felt like I had to push hard on a spirited ride. I think the fact that I was pushing on the pedals with my toes by using the strap ins only exaggerated this. I realized that I had no choice but to ditch the whole biopace toe cage setup with the 175mm arms and stick to the basics. I have very strong joints; this is the first time I ever felt impingement in my knees so I knew I had little other choice. I was limiting my riding and not enjoying the ride nearly as much as I wanted to.

The 190mm crank arms have been significantly easier on my knees, especially when sprinting hard or climbing hills.

Germany_chris

Remember I brought up Q factor somewhere in this or another of your threads, Q factor has as much if not more effect on knee health than crank length. There are many things that affect bike performance and body health no amount of science will narrow it down to one thing read Phil Burt "Bike Fit" it'll give you more than a couple things to think about and is available as a kindle book

Eric F 

Going with longer cranks is an interesting way to fix an issue with your pedaling mechanics. Have you thought about getting some decent cycling shoes and clipless pedals?

aniki

So you were 'pushing on the pedals with your toes; seriously your damn TOES!!!' and you experienced knee pain (surprise, surprise!!) and you thought the problem was the crank length? What on earth led you to this conclusion?

Yes; it's nonsense if you take it as the difference between the 'correct' crank arm length and the 'incorrect' crank arm length. Why do you still not get it? There is no scientific basis behind 'correct' crank arm length; only what works for you. Zinn speaks a lot of sense and has done some amazing things for super tall cyclists but on this subject his method has no scientific or proven basis whatsoever.
Bottom line; if you can't spin your cranks at an efficient cadence they're probably not working for you!
Don't you realise how backwards this is? By lengthening your crank you've just made it harder to spin efficiently; you've increased the range of motion required by your leg joints which may or may not result in injury but why take the chance for no proven benefit? and closed your hip angle which will also probably discourage you from adopting an efficient position. Oh but wait; before your ban you were trying to explain how an upright position on a road bike was optimal because it's how you ride while all the millions of cyclists in the world who ride leaning forward are damaging their bodies....

Power is generated through either torque or cadence; by lengthening your cranks you will generate a little more torque for the same amount of effort but any advantage is then countered by the loss of cadence.
You should have stuck with 175 cranks and concentrated on the position of your foot on the pedal and learning to pedal properly. Instead you've just made another bad decision and tried to justify it to yourself by telling everyone else that they're all doing it wrong.

George Hincapie and Chris Froome both have longer inseams than you and they use 175mm cranks. Do you think their cranks are 'incorrect'?

Fahrenheit531 

If we could just get Rydabent and Moisture into the same thread at the same time...