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Old 07-11-10, 08:48 AM   #1
GetUpnGo
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Need 165mm mountain crank for hybrid

Buying a 17" Jamis Coda Sport and ordering it with mountain gears. http://www.jamisbikes.com/usa/thebik...codasport.html

I have a 29" inseam. According to most sites I consulted, it seems like I would do better with a 165 mm crank. Current crank is FSA Dyna Drive Triple, 48/36/26T. I will be changing that to 22/32/44. The bottom bracket is an FSA sealed cartridge 68 x 110mm. Cassette will be 11-34.

QUESTIONS:

1. A 170mm crank is standard on this bike. How important is it that I change it to 165mm?

2. Is anyone able to find a 22/32/44 crank that would work with this bike? I did some research but I don't understand all the specs well enough. Quality should be equivalent to the FSA Dyna Drive. Hopefully discounted---the LBS is willing to do an even swap, but not if they incur a loss.

Thanks very much for your help!
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Old 07-11-10, 09:00 AM   #2
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With a 29" inseam, I'm surprised that anyone would suggest that you need or should have a 165mm crank. The practical difference with your leg length will near zero, especially for the type of riding you're probably will be doing on this bike.

As you say the bike comes with a 170 crank, which folks much shorter than yourself, all over the world, have been riding for generations. Buy it and ride it that way, and then if you still feel you need shorter cranks you can look around for them.
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Old 07-11-10, 09:39 AM   #3
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I need to choose the crank now to avoid more expense later. Here are some crank lengths recommended for a 29" inseam by various websites:

http://www.nettally.com/palmk/crankset.html 159mm

http://www.cptips.com/crnklth.htm 165 mm

http://www.myra-simon.com/bike/cranks.html 160mm

http://www.sheldonbrown.com/cranks.html "I think people really obsess too much about crank length." He says we can adjust to 5 mm up or down, but he rode 165mm.


I actually can't find a formula that recommends 170 mm for me. There seems to be a lot of agreement that crank length should be related to leg length. Sheldon Brown seems to be a lone dissenter saying we have a range of adaptability.
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Old 07-11-10, 09:52 AM   #4
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170mm will be fine... I know folks much smaller than you that ride 170's with no issues and 5mm is not going to make any noticeable difference.

Shorter cranks are beneficial for people with really short legs and for fixed gear bikes where more pedal clearance is desired for cornering.
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Old 07-11-10, 10:01 AM   #5
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I doubt I could actually tell the difference(when pedaling) of 165 vs 170.
I'm short-5'5"-probably 27' inseam-and I have no trouble with 170 crankarms.
Now I have three bikes one with 165 ,170,175 and I thought they were all 165 until 5 seconds ago when I just took a look.

You get more mechanical advantage with the longer arm, but since your knee is more bent you have less "strength" in that more flexed position-bottom line it is pretty much a wash-especially for your 29" inseam(you are 5-8 or so?)
Save your money.
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Old 07-11-10, 10:16 AM   #6
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Most websites say I should have a 190 mm crank, and I ride anything between 170 - 180. Luckily, the websites don't pedal my bike - I do!

The real test is how the 170s feel to you. If you feel that 170 is too long - like you have trouble spinning at a comfortable cadence - then try a 165.

The expense does not have to be too much and you save little by swapping earlier than later - you can sell the slightly used crankset to save a couple of bucks.

If you try the bike and feel you need it, follow this link -
http://www.speedgoat.com/Catalog.asp...108&Prod=15844

You probably also need a square taper BB to match that crank, but that is around $20. $113 + $20 is a small price to pay to correct an ill-fitting bike..
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Old 07-11-10, 10:31 AM   #7
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The 170 crank has been the standard crank for generations, and folks of all heights have been riding them for over 75 years on all kinds of adult bikes. Early on most of the crank length "science" focused on how the average height has increased since WWII and that a standard created back then was antiquated for today's taller population. This led to the creation of longer cranks, with some now available up to 180mm as standard.

But let's think about this reasonably, the range of adults leg lengths is probably over 6" or more, yet the available adult cranks vary by less than 3/4" so obviously there's lots of latitude in usable crank length. The simple fact is that for most folks, on most bikes it simply doesn't matter. If you were a competitive athlete there might be some advantage to shorter or longer cranks, but it's more dependent on riding style than leg length.

Don't let what you read on fitting sites make you crazy or waste dough. Folks well shorter than you ride 170s including top pros, (and even 175s for MTB) with no problem at all.

FWIW- I'm 5'8 with a 29" inseam and have been riding 170s for over 100,000 miles over the last 44 years.
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Old 07-11-10, 10:40 AM   #8
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GetUpnGo, My personal experiance tells me that Sheldon Brown's comments are spot on. While a 170mm crankarm may work fine if you have personal doubts go with the 165.

Brad
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Old 07-11-10, 10:55 AM   #9
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I assume you are talking about leg length. Mine is 33.75" and I ride 172.5s. Peter White has an interesting take on it. http://www.peterwhitecycles.com/fitting.htm
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Old 07-11-10, 10:57 AM   #10
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Quote:
Originally Posted by GetUpnGo View Post
1. A 170mm crank is standard on this bike. How important is it that I change it to 165mm?
If you can't feel a 10mm difference in your saddle height, then the difference between 170 and 165mm cranks is absolutely nothing. Don't fret over it.
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Old 07-11-10, 11:27 AM   #11
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I really like my 167.5mm cranks.

Good luck finding some..
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Old 07-11-10, 11:57 AM   #12
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This is another example of how newbies and casual riders can get worked up over something that more serious riders simply ignore.

There might be theoretical benefits of one crank length over another, and it might be germane if the OP were riding at a competitive level on a bike at a similar level, but the fact is that he's a casual cyclist, riding a mid-level bike and any subtle difference is irrelevant for the his/her purposes.

The irony is that folks on this forum engage in long debates on issues that professional competitive cyclists don't care about. Pro's routinely accept sponsor or team supplied equipment, knowing full well that in the final analysis riding is more about the engine than the vehicle.

I'm not invested in your bike, and don't care what you end up with, but if you want the advice of someone with 40+ years experience at all levels within the bike industry, buy the bike and ride it as is, and forget you ever went to these fit sites. Once you have it you'll wonder what all the fuss was about in the first place.

BTW- has anyone noticed that this bike has a suspension seatpost with travel greater than the difference in crank diameters.
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Old 07-11-10, 12:11 PM   #13
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Originally Posted by joejack951 View Post
If you can't feel a 10mm difference in your saddle height, then the difference between 170 and 165mm cranks is absolutely nothing. Don't fret over it.
I can definitely feel a 10mm difference in my saddle height. I can easily feel a difference of 5mm.
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Old 07-11-10, 12:14 PM   #14
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I switched from 175 to 170 mm cranks on my commuter sometimes last year, and best I can tell it keeps my knees happier. I have no problem riding my MTB which still has 175 mm cranks, and I'm still faster on the MTB than on the commuter. I get more sore though.

Not entirely certain how general this is though, the commuter cranks also have a higher q-value, and I have a previous issue making my knees sensitive.
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Old 07-11-10, 12:22 PM   #15
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This is another example of how newbies and casual riders can get worked up over something that more serious riders simply ignore..
Your difinition of "newbie"? Have done my obligatory 2000mi/year + century + 1000 mi tour of Europe + biking for the last 48 years. Not really a newbie---just very thorough. I think crank length becomes important on long days in steep terrain, which describes where I bike. A shorter crank might make that type of terrain a bit easier. Would also like to minimize impact on the hip joint.

Serious is a relative term. Biking is pretty important to me, hence my thorough search for the right components.
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Old 07-11-10, 12:47 PM   #16
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I'm sorry if I offended you, but I'd expect that with your experience you'd already have determined your favored crank length, and not be hunting around on various fit sites.

If you'd simply said that you were an experience rider and preferred to stay with 165s, we wouldn't be debating the importance, and would simply have tried to help you locate them. BTW- if all this experience is with 170mm cranks you might want to stay with them, experience and habit trumps theory.
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Old 07-11-10, 01:38 PM   #17
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Wellll . . . title was "Need 165mm mountain crank for hybrid ." I think that if I could find the right 165 mm crank, it would be preferable. I cited both sides of the debate, so I'm not strongly committed to one side or another. I chose 165 for my last road bike and liked it a lot. I just checked my current hybrid and it's got a 175, to my great surprise. So I guess 170 will be an improvement.

Not really offended, just filling you in on my specs. :-)) Back in the early 70s when I first started riding seriously consumers didn't ask many questions because there were so few choices among bike models and components. Plus there was no internet so we were much less informed about components. The vast majority of people were on the totally wrong bike anyway ("10-speed racer") so components didn't matter much. Just saying that most of us spend time "hunting around on various sites" to improve our knowledge.

I posted because I think the FSA Dyna Drive is available in a 165 with the gears I desire, but I can't find one for sale on the net. Was hoping someone might know where to look. Jenson's has it in 170. Also I wanted to test my assumption that 165 would be better, and I appreciate the variety of opinions, based on people's idrect experience. If I can't find a 165 I won't worry about it.
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Old 07-11-10, 01:57 PM   #18
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Originally Posted by GetUpnGo View Post
Wellll . . . title was "Need 165mm mountain crank for hybrid ." ... I chose 165 for my last road bike and liked it a lot. I just checked my current hybrid and it's got a 175, to my great surprise.

Also I wanted to test my assumption that 165 would be better, and I appreciate the variety of opinions, based on people's idrect experience. If I can't find a 165 I won't worry about it.
I think the first part of your post makes my point that it doesn't make a material difference. You've been riding longer cranks and didn't even know it.

But here's my more serious point. I post on forums out of a moral sense of obligation to help newer riders, and share the benefits of knowledge and my 40+ years of experience. I've little or no interest in debates with people who've already made up their minds, which is why I never debate politics, religion, or chain lube (which is my business).

If you'd simply asked "where can I find....." I would have let someone with specific knowledge answer. But you came on as (seemingly) a newbie, and others and myself endeavored to save you time and money by saying that for your purposes it didn't matter.

If you want advice, ask for it, if you want to start a debate on the relative merits of something say, "I've been using ... and am considering a change to ... because I want to improve .... . Then folks can write to that point if they want to, and others can pass and give their time to help someone who genuinely needs it.
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Old 07-11-10, 09:12 PM   #19
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"I post on forums out of a moral sense of obligation to help newer riders, and share the benefits of knowledge and my 40+ years of experience."

I'm speechless. Are you the welcoming committee for Bike Forums? I sure hope not. Do you really think you can dictate to others what they can and can't post and how things should be phrased?

How about you refrain from bullying out of a moral sense of obligation to respect others?
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Old 07-11-10, 09:22 PM   #20
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Originally Posted by GetUpnGo View Post
"I post on forums out of a moral sense of obligation to help newer riders, and share the benefits of knowledge and my 40+ years of experience."

I'm speechless. Are you the welcoming committee for Bike Forums? I sure hope not. Do you really think you can dictate to others what they can and can't post and how things should be phrased?

How about you refrain from bullying out of a moral sense of obligation to respect others?
Don't quote me out of context. The next sentence was "I've little or no interest in debates with people who've already made up their minds, which is why I never debate politics, religion, or chain lube (which is my business)."

In two of your threads where I posted, you opened with what appeared to be a newbie question, got advice then started to debate the advice and move it to another direction. The advice is free, but I prefer to help those who actually need it rather than those who come back claiming enough experience not to need it in the first place.

I'm not bullying or censoring you. It's very simple, you're free to post anything you wish, and I'm free not to bother responding.
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Old 07-11-10, 09:51 PM   #21
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I have to say I agree, in part. The OP seems to have made up his mind before he hit the post button. Thus, I don't see the point of posting questions when one isn't interested in anything anyone has to say.
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Old 07-11-10, 10:19 PM   #22
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personally, I prefer 165mm cranks, even though I'm 5'7 with 31" inseam.
I can't quite put my finger on it, but I'd guess it's a flexibility issue.
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Old 07-12-10, 12:30 PM   #23
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If anyone has managed to read this much of the thread and miss this statement (possibly including the OP)

Quote:
Originally Posted by GetUpnGo View Post
QUESTIONS:

1. A 170mm crank is standard on this bike. How important is it that I change it to 165mm?
...

Thanks very much for your help!
For what it's worth I have a 29" pants inseam, a 31.5" bike inseam, am 6'1", and prefer 165mm cranks for road and I'm happy with 165 or 170 for mountain. The difference between 170 and 175 isn't huge but it is noticeable.

I think Sheldon had a pretty good grip on this. It's not that crank length doesn't matter, but like walking up really tall (or short) stairs may be uncomfortable/sub optimal, but workable and generally non harmful, the right crank length (for your build, bike type/geometry, gearing, riding style, and terrain) will be more comfortable (and possibly more efficient), but minor variations will often go unnoticed, and people will generally be most comfortable with whatever they've gotten used to.
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Old 07-13-10, 08:00 AM   #24
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My goal in posting this thread was twofold:

1. To get others' viewpoints on my thinking that a 165mm crank would fit me best. I received enough helpful replies on that to decide that although 165mm would probaby be best, it is not crucial and I will most likely be able to adapt to a 170 mm crank.

2. To find out where to obtain a 165 mm mountain crank. No answer to that yet.

I have no idea why my wanting to engage in discussion of this question would lead to so much animosity. I'm looking for a friendly, helpful biking forum where I can engage in peaceable back and forth discussions to learn more. My brief passage through this forum has not been that much fun and I think I will continue looking for the right forum. Would appreciat suggestions for other forums. Thank you.
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Old 07-13-10, 08:17 AM   #25
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GetUpnGo, In any large forum there will be quite a personality pool for yours, or mine to clash with. Enjoy your new bike.

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