# What do I need to switch to a compact crank?



## armstrong (Jul 9, 2013)

I'm starting a new thread cause I asked this in another thread and it's buried there.

I currently have 172.5 FSA Gossamers that are too long. My height (166) suggests I'm better off with shorter cranks so I've found 165 ultegra 6700s that are compacts, which I think are a good idea. Everything in the ad is here:

https://imageshack.us/a/img703/9818/5gbo.jpg
https://imageshack.us/a/img843/1397/vkhl.jpg
https://img826.imageshack.us/img826/1102/owdl.jpg

What other hardware do I need? Are BBs once-size-fits all? Do I also need to change my cassette? It's currently a 10 speed with a 6500 ultegra RD (not sure what chain or cassette I have, not handy right now). I want to have everything with me when I go to the LBS to get the swap done. 

Thanks in advance.


----------



## junior1210 (May 2, 2013)

Need more info before anybody can answer your question.
What frame do you have? And more importantly; do you know what size BB you have now?
Once you have that info, I'd look for crank that would work with your current BB (less work to swap out). If you can't find one (at a good price), then look for crank/BB set of proper size. As long as your new crank is same number of gears as the old crank, there's no reason to fool with the cassette unless the gear combos will be somehow untenable. Depending on the size of your current crank, you may need to shorten your chain (might be wise to just get a new chain and start fresh). Might not be a bad idea to stop in at the LBS before doing the work and discuss it with them. If the shop is decent, they can tell you what you'll need and recommend what to get, as well as give you a ballpark of the cost (so you go in eyes wide open).


----------



## armstrong (Jul 9, 2013)

It's a Cinelli Xperience. I know what I believe is the sides of the BB said "Mega Exo" on it when I looked at it this morning. Did you see the photos I linked? I think the cylinder thing is the (ultegra) BB isn't it? The ad is for everything in the 3 photos.

This is a photo I took of my bike's crankarm in the past, not sure if it gives you any additional information:
https://img13.imageshack.us/img13/2685/zwyp.jpg

I don't know what size BB I have now (I'll look tonight). Problem is, I'm travelling far away (about 4 hrs) leaving tomorrow morning and staying till Sunday. The seller happens to be out in that direction so I don't have time to visit the LBS first. It's not somewhere I normally drive so I won't easily get a 2nd chance at buying it unless we go mail.


----------



## junior1210 (May 2, 2013)

Yes the cylinder thing is the BB. The BB you have is a Mega Exo BB, however what you need to know is the BB shell width of your frame. I'm 85% sure it is 68mm w/English thread, but I could be wrong and the wrong size wont work. Until you know for sure what size you need you won't know what to get. Also keep in mind that the BB size will determine what cranks you can use (if you need a 68mm crank, a 73mm won't do).
While that crank may work (pictures only tell so much), I'd be leary of the BB. Used bearings could be a potential problem, best to have your shop check it out for you if you decide to buy it. If you still don't know what BB size you need, give that crank set a pass until you do know.


----------



## PJ352 (Dec 5, 2007)

I'd go back to the fundamental question of why you're swapping out your 172.5's for 165's.

I don't know your inseam/ femur length, but at your height (and in general) you'd probably be better off with the 172.5's.


----------



## armstrong (Jul 9, 2013)

>I don't know your inseam/ femur length, but at your height (and in general) you'd probably be better off with the 172.5's.

According to this guy, I'd be best with a 155.
How to Fit a Bicycle

I'm not tall (5'6). It makes sense to me shorter cranks should be better for me. Am I mistaken?


----------



## armstrong (Jul 9, 2013)

>junior1210

Before I go any further, thanks for your help.

OK - so I went home and checked out all the inscriptions on the BB and cranks and bike. 

On the BB, I see
- mega exo
- BC 1.37'x24T
- inscriptions regarding torque required (40-60 N-m)

On the bike (on the shell?) when you flip the bike upside down, it's on the cylinder thing housing the BB.
- 7MCL46, followed underneath it by 3124 (I'm guessing nothing particularly important)

On the L crank:
- CK-6020

On the R crank:
- CK-6020 BCD 130 

So what questions should I ask the seller? It's another hour or so drive that I have to make to meet him, so it'll help to know if it's compatible or not.

Regarding the shell, I took a pic. What I'm assuming is the shell appears to be a 68 (parallax might show otherwise)
https://img94.imageshack.us/img94/2931/i2ep.jpg


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> >I don't know your inseam/ femur length, but at your height (and in general) you'd probably be better off with the 172.5's.
> 
> According to this guy, I'd be best with a 155.
> How to Fit a Bicycle
> ...


For every 'expert' opinion on fit, you can find an opposing argument from another 'expert' . All that tells me is that fit is a sea of gray as opposed to black and white. Like anything else, what works for us is what we subscribe to, thus the followers of White, Hogg's, Friel and others. FWIW, I agree with some of what all of them say, but part on other facets. 

Again, generally speaking, at your height, you'd be sized somewhere in the 51-52cm frame range. The vast majority of OE cranks fitted to those bikes are... what. 170mm's, are they not? 

Ideally (in text book terms) you'd be running 170's, but your 172.5's are going to change saddle height less than the 165's. Something to think about, IMO. 

Remember too, that going to shorter cranks is going to change your KOPS baseline (another hot fit topic). I suspect the result isn't going to better your f/r weight distribution or power transfer.


----------



## PJ352 (Dec 5, 2007)

You have an English threaded (BC 1.37x24), 68mm BB shell.


----------



## junior1210 (May 2, 2013)

Pj352 called it. Now you need to find out if that crank you want to buy is 68mm as well (most likely is). Like I said before, if you buy that crank/BB set, have your shop check those bearings before installing. If they're no good, new BB won't cost that much. You'll also have to have your chain re-sized for the new crank, or might be better to just get a new chain and avoid hassles of an old chain with stretch issues. Your front derailleur will have to be repositioned and adjusted as well. This stuff isn't all that hard to do, and any competent shop could do the job in about an hour or so.

Since your bike will be on the stand, if cost isn't a issue, I'd just have a full tune up done.


----------



## Jay Strongbow (May 8, 2010)

armstrong said:


> >I don't know your inseam/ femur length, but at your height (and in general) you'd probably be better off with the 172.5's.
> 
> *According to this guy, I'd be best with a 155.*How to Fit a Bicycle
> 
> I'm not tall (5'6). It makes sense to me shorter cranks should be better for me. Am I mistaken?


Really? Where? I did see where he said "So how long should the cranks be? Well, that's a good question. I wish I had a good answer but I don't." but I missed the part where he said you personally should use 155 cranks.


----------



## Jay Strongbow (May 8, 2010)

armstrong said:


> *It's a Cinelli Xperience. * I know what I believe is the sides of the BB said "Mega Exo" on it when I looked at it this morning. .


According to everything I could find on the internet that bike comes with a compact.

You do realize the term 'compact' relates to the gearing and not the crank arm length, right? 
It sounds like you are buying a new crankset when you just want different length arms.


----------



## armstrong (Jul 9, 2013)

He said the 18.5% measurement. For me that measures to 155. So I'm sorry I wasn't more precise. In any case, the point is, it would seem 172.5 is probably longer than I need.

>According to everything I could find on the internet that bike comes with a compact.

I bought the bike used this summer. It's how I got it.

>You do realize the term 'compact' relates to the gearing and not the crank arm length, right? 

Killing two birds with one stone. In a few other threads, folks mentioned/recommended I consider a compact crank (I was thinking of changing it to a triple).


----------



## armstrong (Jul 9, 2013)

>For every 'expert' opinion on fit, you can find an opposing argument from another 'expert' . 

I can appreciate this, but that doesn't tell me that 172.5 is necessarily good for me, or that it is better than 165.

I'm not trying to challenge your "expertise", I really am not. I've taken alot of the recommendations on this forum seriously (went and trued wheels, tune up my 2nd bike, got pedals based on a suggestion here). But the way I'm looking at things is this. I'm 5'6. I'm not tall. Average men run about my height up to up over 6 feet. Cranks go generally from 165 to 175. In general, longer cranks fit taller people. So it would seem a 172.5 would be a better fit for someone (say) 6 feet or so. I understand torque and "levers" etc. and a longer crank might/will generate greater torque, but there is more to cycling and crank-fitting than just that. So are you telling me not to switch to 165 because I won't notice the difference, or is it that you know 172.5 is better, or that since it's all a grey area, just to not bother changing at all, since someone somewhere will have a theory as to why a 172.5 is optimal for me? I'm not trying to be facetious, but I'm not a tall guy so it doesn't translate in my brain why 172.5 isn't (in most theories) too long for me. If you don't think I'll notice a difference because I'm just a noob then that's fine too, but at least explain why you seem to be disagreeing with this move.

Put another way, say I had 165s and wanted to switch to 172.5, what would you be posting in this thread regarding this scenario?


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> >For every 'expert' opinion on fit, you can find an opposing argument from another 'expert' .
> 
> I can appreciate this, but that doesn't tell me that 172.5 is necessarily good for me, or that it is better than 165.
> 
> ...


First off, let me say I'm not at all offended or put off by your questioning what I've offered. It's your money, your bike and you're the one riding it, so making changes with eyes wide open isn't at all a bad thing.

That said, on to your comments. Longer crankarms aren't really for taller people. They're for people with longer femurs, which are generally taller people. One point you're disregarding here is that given your height and assuming average proportions, you'd likely take a 51-52cm frame. If you peruse bike specs for those frames, almost invariably, the bikes are equipped with 170mm crankarms. There's a reason for this, and as I've stated, that's likely your ideal length.

Now, given the choice of a little shorter or a little longer, I'd stay with the 172.5's, because they represent the smallest deviation from your ideal (IMO). In short, adding 2.5mm's is better than taking away 5. As a peripheral advantage, KOPS is less affected.

As far as not noticing the difference, it's not because you're a noob. Almost no one would consciously be aware of such a minor change. Increase that change, and you increase the possibility that there will be a discernible effect. 

Bottom line, I'm disagreeing with this move because (IMO) you're spending money and making a change that has the potential of having an adverse affect, with almost no possibility of improving your fit or performance. If you're hellbent on making a change, go with 170's, but I'd stay with the 172.5's.


----------



## junior1210 (May 2, 2013)

Sorry I can't contribute to the fit question since that is rather outside my zone of knowledge (except for myself), but I'd think hard before doing this swap if you don't need to. FSA aren't my favorite cranks since I'm currently having issues with my own FSA cranks right now, but if they work for you why change? The Ultegra's are a step up for sure, but you already have the FSA's and if there's nothing wrong with them why spend the money? Don't get me wrong, if you're sure this is what you want go for it, just be sure this is what you need to do before changing a set up that works. Also FWIW the cranks you have are better looking than the Ultegra's IMO.


----------



## armstrong (Jul 9, 2013)

PJ352 said:


> One point you're disregarding here is that given your height and assuming average proportions, you'd likely take a 51-52cm frame. If you peruse bike specs for those frames, almost invariably, the bikes are equipped with 170mm crankarms. There's a reason for this, and as I've stated, that's likely your ideal length.


I thought 170s were the industry standard and basically went on bikes of all sizes. Maybe I'm wrong, but if this assumption were correct, then 170 isn't "my" ideal length, but a one-size-fits all size that assumes an average human (male) height. Given I'm below that, then wouldn't it mean that if I were to correct the length, it would be downwards, not upwards. So while 170 is a little too long, 172.5 would be a lot too long (even though it is closer to 170 than 165 is). Whether 172.5 is closer to my ideal than 165 is another discussion, but I'm just saying.

Do larger bikes ever have stock 172.5 or 175 cranks? Do small bikes stock 165 cranks?


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> I thought 170s were the industry standard and basically went on bikes of all sizes. *Maybe I'm wrong*, but if this assumption were correct, then 170 isn't "my" ideal length, but a one-size-fits all size that assumes an average human (male) height. Given I'm below that, then wouldn't it mean that if I were to correct the length, it would be downwards, not upwards. So while 170 is a little too long, 172.5 would be a lot too long (even though it is closer to 170 than 165 is). Whether 172.5 is closer to my ideal than 165 is another discussion, but I'm just saying.
> 
> Do larger bikes ever have stock 172.5 or 175 cranks? Do small bikes stock 165 cranks?


Sorry to say, you are wrong. Check out the geo chart below. IME it's representative of what you'll find elsewhere. What do you see for crankarm lengths across the frame sizes?

Specialized Bicycle Components


----------



## armstrong (Jul 9, 2013)

PJ352 said:


> Sorry to say, you are wrong. Check out the geo chart below. IME it's representative of what you'll find elsewhere. What do you see for crankarm lengths across the frame sizes?
> 
> Specialized Bicycle Components


I see that crank arm length increases with larger frames.

I have a 48 cm. What does that tell you about what is the best crankarm length I should have? Using your argument that 172.5 is closer to 170 than 165 is, but absolute value isn't everything. 171 is the same amount of "error" as 169, but for a short person, 169 is a better fit. So absolute error really doesn't tell the whole story.


----------



## OWSI (Mar 11, 2009)

I would ask yourself what are you trying to fix? Do you have a specific problem that you are addressing with fit by going to a shorter crank arm?
I am no expert by any means but I do believe that changing the length of the crank arms will effect the saddle position. To keep the same knee over pedal spindle position you will need to move the saddle aft and to keep the saddle height position you would raise the seat post. These changes would then change the saddle to bar drop and reach, and also change your center of gravity and f/r weight ratio. So give some thought to how the total fit comes together.
Back to your original question though.... I don't know enough about the various BB configurations, so if I were considering making this change I would visit my LBS and get their input into what my options were for changing to a different BB or find a crankset that used the same BB as what you currently have.


----------



## armstrong (Jul 9, 2013)

OWSI said:


> I would ask yourself what are you trying to fix? Do you have a specific problem that you are addressing with fit by going to a shorter crank arm?


No I don't. I bought the bike "as is" this summer. I realize "as is" isn't always optimal for me, so I've read up on various fitting guides etc. and it seemed logical to me that crank arms was one area where it probably wasn't the best fit to me. I still haven't seen a single compelling counterargument to the height-related perspective I've brought forward in this thread. 172.5 is greater than average. i'm below average height. ergo, cranks too long. whether 165 is too short is another argument, but according to at least one theory, even 165 is 10 mm too long.

I have the opportunity to get the ultegra cranks you see in the first post at well below market value, and I can always sell the FSAs I have on Kijiji (and very possibly at a cost exceeding what I have to pay for the ultegras). So i'd only be paying an LBS for labour. so given i already have all-ultegra drivetrain, i thought it wasn't a bad move to do. it seemed like the right purchase to come along for a lingering issue (too long cranks). 

anyways, i'll investigate and research further if any changes should be made.


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> I see that crank arm length increases with larger frames.


Yes, and maybe more importantly, it decreases to 170mm's in smaller frame sizes. 



armstrong said:


> I have a 48 cm. What does that tell you about what is the best crankarm length I should have? Using your argument that 172.5 is closer to 170 than 165 is, but absolute value isn't everything. 171 is the same amount of "error" as 169, but for a short person, 169 is a better fit. So absolute error really doesn't tell the whole story.


I don't *know* what the best crankarm length is for you, but going by best practices, I think 170mm's is a good starting point, making your 172.5's a second best - and better than 165's. 

In this sea of gray called fit, absolute error doesn't tell the whole story, but following established standards is generally a good starting point. 

Similar to what OWSI offered, assuming you've had a proper fitting, remember that if you go with 165mm crankarms, both your saddle height and fore/ aft will change 'some'. The latter _may_ change f/r weight distribution enough to matter, but no way to tell for sure.


----------



## OWSI (Mar 11, 2009)

I am not going to be the one to give you a compelling argument. I will however share my opinion.... If it were me (and it's not) with no real issue that I was trying to correct I would consider the following.... If I could comfortably maintain a cadence of 90+ RPM, I wouldn't make a change. If I could not maintain a comfortable cadence of 75 RPM I would consider changing to a shorter crank. If my cadence was comfortably between 75 and 90 RPM, I am reasonably sure with some concentrated training I could get it up to 90+. In only a few weeks time I have taken my comfortable cadence from 70 RPM to 85+ RPM. Doesn't mean the same would be true for you though.


----------



## armstrong (Jul 9, 2013)

Since we seem to be here picking apart each other's arguments, I'll just point out the following.

>Yes, and maybe more importantly, it decreases to 170mm's in smaller frame sizes. 

You have to therefore concede 172.5 is going in the wrong direction. 

>I think 170mm's is a good starting point, making your 172.5's a second best - and better than 165's. 

I think you would hopefully agree that 165 is 3rd best and not 175. Both are 5 mm away from 170 are they not? But using the same logic you've brought to this thread, both 175 and 165 should be tied for 3rd best.

So I think what we can agree on is this: Whether 2.5 in the wrong direction or 5 mm in the right direction is better becomes a matter of opinion rather than a matter of fact.


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> Since we seem to be here picking apart each other's arguments, I'll just point out the following.
> 
> >Yes, and maybe more importantly, it decreases to 170mm's in smaller frame sizes.
> 
> ...


I'm not picking apart your argument. I think your logic is fundamentally flawed.

You're contemplating making a change when no problem exists, with the end result _possibly_ having an adverse affect on your fit. More likely, having little effect at all - but at a financial cost. Makes no sense to me.

And yes, 172.5 is going in the wrong direction from what I perceive as your best starting point, but 165 strays more significantly, necessitating more significant fit changes. IMO, 175 would be worse (for you) than 165. I've never said otherwise. 

This brings us back to the fundamental of... why do this?? Research? Theories? As I've mentioned, where talking a sea of gray here, with most cyclists making fit changes when warranted, based on their riding experiences. Cycling is, after all, a physical activity. 

So, rather than make points/ counterpoints, maybe my best advice to you should be_ ride more, research less_. :wink5:


----------



## PlatyPius (Feb 1, 2009)

165 cranks are for mutants with stubby legs. Pretty much every bike on the planet that is a 48cm comes with 170 cranks. My inseam is 29". Technically, I should have 170mm cranks. I use 172.5 cranks because: a) It doesn't f-ing matter. b) Bikes in my size come with 172.5 cranks. On my mountain bikes I use 175 cranks. How much difference do I feel? None.

You'd have to have an inseam of 26" to "need" 165mm cranks.


----------



## Mike T. (Feb 3, 2004)

PlatyPius said:


> You'd have to have an inseam of 26" to "need" 165mm cranks.


Or ride a 50 degree steep banking like I do


----------



## OWSI (Mar 11, 2009)

OP.... What measurement are you using to apply the 18.5% to? Are you using your inseam measurement or top of femur to floor? My inseam is 31.5 inches (~ 775mm) and my Top of Femur to floor is about 36 inches (~ 915mm). Make sure you are using the correct measurement.


----------



## armstrong (Jul 9, 2013)

PJ352 said:


> Sorry to say, you are wrong.


Just want to point out that 165s do act as stock cranks on some bikes.

https://www.giant-bicycles.com/backoffice/_upload_au/184_Print_quality2013_SB_print_single_pages.pdf

Not trying to be a prick or whatever, but given the certainty with which you declared me to be wrong on this matter, it really behooves me to show that in fact, you were wrong in the matter.

This is neither here nor there though as I have decided just to stay with the cranks I have.


----------



## armstrong (Jul 9, 2013)

OWSI said:


> OP.... What measurement are you using to apply the 18.5% to?


I'm guessing I'm doing the measurement wrong. The measurement was made according my interpretation of what I read, and I came up with a length, that when multiplied by 0.185, gives me 155.5 mm. I figure the measurement was wrong cause though I'm not tall, I'm not THAT short among the world's population. If I need a 155, some folks shorter than me would need 145s and I really don't buy that.


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> Just want to point out that 165s do act as stock cranks on some bikes.
> 
> https://www.giant-bicycles.com/backoffice/_upload_au/184_Print_quality2013_SB_print_single_pages.pdf
> 
> ...


Nowhere in this thread did I state that 165's were *never* fitted to any frame sizes. Since the thread was yours, and you take (IIRC) something around a 49-51cm frame, my 'argument' was that if you checked sizes in your range, almost invariably, they're fitted with 170mm crankarms - and they are.

All your chart shows me is that some nominally sized *43cm frames* are fitted with 165mm crankarms. If anything, it proves me right, and I thank you for that. :wink5:


----------



## armstrong (Jul 9, 2013)

I wrote:
>_I see that crank arm length increases with larger frames._

To which you wrote:
>Yes, and maybe *more importantly*, it *decreases to 170mm's in smaller frame sizes*.

I'm glad you remain the optimist (narcissist?) and view this exchange as somehow *proving* you right.


----------



## armstrong (Jul 9, 2013)

PJ352 said:


> This brings us back to the fundamental of... why do this?? Research? Theories?
> 
> So, rather than make points/ counterpoints, maybe my best advice to you should be_ ride more, research less_. :wink5:


Since you're so smart-aleky, then I might as well.

Good thing Peter White didn't take up your advice otherwise he would never have discovered a fix that led to an "immediate improvement in power and endurance" and become the expert he is on bike fitting.

How to Fit a Bicycle


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> I wrote:
> >_I see that crank arm length increases with larger frames._
> 
> To which you wrote:
> >Yes, and maybe *more importantly*, it *decreases to 170mm's in smaller frame sizes*.


All accurate, except that you ignored where I previously wrote...
_Since the thread was yours, and you take (IIRC) something around a 49-51cm frame, my 'argument' was that *if you checked sizes in your range*, almost invariably, they're fitted with 170mm crankarms - and they are. _

I never said the _smallest_ frame sizes. I said _smaller_, as in, your size range.

Some of the bikes listed on the chart are women's. Unless you're a woman, kinda irrelevant. 

/pj


----------



## armstrong (Jul 9, 2013)

PJ352 said:


> All accurate, except that you ignored where I previously wrote...
> _Since the thread was yours, and you take (IIRC) something around a 49-51cm frame, my 'argument' was that *if you checked sizes in your range*, almost invariably, they're fitted with 170mm crankarms - and they are. _
> 
> I never said the _smallest_ frame sizes. I said _smaller_, as in, your size range.
> ...



I understand that. It's just when you wrote what you did, I thought you were telling me that 165s just didn't exist on bikes. Re-read the thread. You can't fault me for being mistaken about that. That's what I read and digested. It wasn't my communication or comprehension error. That is what was largely implied, particularly by your "more importantly" highlight. That was the point of your post, and it certainly seemed to imply cranks stop at 170.


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> I understand that. It's just *when you wrote what you did, I thought you were telling me that 165s just didn't exist on bikes. Re-read the thread. * You can't fault me for being mistaken about that. That's what I read and digested. It wasn't my communication or comprehension error. That is what was largely implied, particularly by your "more importantly" highlight. That was the point of your post, and it certainly seemed to imply cranks stop at 170.


I just reread each one of my posts. Again, I say _nowhere in this thread did I state that 165's were never fitted to any frame sizes._ 

Anyway, I'm glad you stayed with the cranks. I think that was a good choice.


----------



## armstrong (Jul 9, 2013)

PJ352 said:


> I just reread each one of my posts. Again, I say _nowhere in this thread did I state that 165's were never fitted to any frame sizes._


We can disagree but I would opine that your 170 statement implied that. Cranks were proportional to frame size, but MORE IMPORTANTLY, 170 was found on smaller frames. Your argument was why I should not use 165 - it's because 170 was found on smaller frames.

I'll also opine that if you have to resort to technicalities to prove that you didn't contradict yourself, then you weren't proven right by those remarks but were very close in fact to being proven wrong.


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> Your argument was why I should not use 165 - it's because 170 was found on smaller frames.


My argument was that 170mm crankarms were generally OE'd on frames in your size range, thus your ideal, at least 'on paper'.

I also said "rather than make points/ counterpoints, maybe my best advice to you should be ride more, research less". 

I'll stand by that statement as well. 

And.. feel free to carry on with your rant.


----------



## armstrong (Jul 9, 2013)

I've thought about what you posted and yes you don't contradict yourself.

But look at the crank length of the smallest bike described in the link you shared, and see why there was a misunderstanding.

Anyways - I'm not looking for a fight but given some of your smart-aleky remarks I'll be happy to take the last word. But you'll have to cooperate as well. It takes two to tango.

Regarding your advice, I already addressed that above but you seem to have missed it. It's here:

What do I need to switch to a compact crank? - Page 2


----------



## PJ352 (Dec 5, 2007)

armstrong said:


> Regarding your advice, I already addressed that above but you seem to have missed it. It's here:
> 
> What do I need to switch to a compact crank? - Page 2


Already stated my viewpoints re: the 'experts'/ fit in post #11. It's perfectly acceptable to me that you disagree.


----------



## armstrong (Jul 9, 2013)

I'm not disagreeing with your position that there is no consensus on fit. What I wrote was the following.

You wrote:

_This brings us back to the fundamental of... why do this?? Research? Theories? _

_So, rather than make points/ counterpoints, maybe my best advice to you should be__ ride more, research less.







_

To which, I wrote: 

Since you're so smart-aleky, then I might as well.

Good thing Peter White didn't take up your advice otherwise he would never have discovered a fix that led to an "immediate improvement in power and endurance" and become the expert he is on bike fitting.
How to Fit a Bicycle


----------



## Jay Strongbow (May 8, 2010)

armstrong said:


> I'm not disagreeing with your position that there is no consensus on fit. What I wrote was the following.
> 
> You wrote:
> 
> ...


I suspect you have no idea how silly you sound but trust me it's extreme.
You clearly feel you know everything you need to know about this topic so perhaps picking petty arguments with someone who actually does know what they are talking about isn't necessary for you.


----------



## jpick915 (May 7, 2006)

Just buy the damn thing.


----------



## armstrong (Jul 9, 2013)

Jay Strongbow said:


> I suspect you have no idea how silly you sound but trust me it's extreme.
> You clearly feel you know everything you need to know about this topic so perhaps picking petty arguments with someone who actually does know what they are talking about isn't necessary for you.


Oh believe me I realize how elementary-school this all is. I don't need to come on to these forums to feel good about myself. But he started all the narcissism I know better and you don't, and and I'm more than happy to oblige.


----------



## loxx0050 (Jul 26, 2013)

Maybe I missed this reading through the thread progession, but I realize you have bought a used craigslist bike and are trying to get the thing to the right fit. Which I completely understand as my main road bike I bought used off of craigslist also and still mess with the settings here and there to get the perfect fit (mainly it is stem height and cleat position now as I have new shoes I am trying to figure out). 

But, you never really mentioned how the bike feels with the crank it currently has? Does it feel too long and do you feel it puts more stress on your knees than it should? You mention according to research your ideal crank length is shorter than what you have but never mention (again, I may have missed this) if the current crank feels fine or not. Also, your frame size you mentioned (48cm from what I saw) seems a bit small for you based on your height alone but we don't know the whole story (i.e. inseam, leg length portions, torso length, arm length, flexibility and the list goes on). I would've guess you would be a 50-51 (52 on some bike frames depending on the geometry). How does the rest of the bike feel? Have you gotten a proper fitting or are still messing with it on your own? 

Just trying to understand better. I've tried out some of those other websites that calculate which sized crank you should use and it also says I should use around a 165 but some up to 170 or so (which varies from site to site). But bear in mind I am taller than you at just over 5'9" and ride a 54cm frame with a 30.5-(just under) 31" inseam roughly. But, my road bike has 175 cranks and it feels fines most of the time (some knee pains on the toughest gears but working on cleat position currently still). I also pick up another bike that has 172.5 cranks and have ridden it yet with my clipless pedals yet but on the test rides I didn't notice a difference with the cranks personally.


----------

