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View Full Version : Crankset change--advice appreciated!



Ana
11-15-2008, 04:45 PM
So after tweaking my fit, I've decided I want to try a shorter crank length since the longest part of my leg extension is not at the bottom of my stroke.

I want a 165mm and have a 170mm. I want some advice about getting it switched since I am not yet handy (or properly equipped) to do it myself.

I only have one nice road bike and have no need for a 170mm crank (after all, I'm only 5'3" with a "long torso for my height" which translates into short legs). My bike is Shimano 105 triple and is only 18 months old and has less than 1,000 miles on it. I change the chain regularly so I think it's in pretty good shape. I want to keep it at Shimano 105 or better and I know labor will need to be done but I want to stay around $200 or less. What is the standard protocol? Can I ask for a credit for the crankset and let them keep it or should I keep it and try to sell it myself?

And if so, how much credit do you think would be reasonable?

What is the best thing to do?

Any stories of others who have had their cranks changed? It's a huge hassle for me to do this since I do not own a vehicle so I can't do a lot of shopping around but there is a shop I prefer.

bike4ever
11-15-2008, 05:51 PM
You said this was a triple - is it a compact triple (50-39-30)? Or is it a traditional triple - 52-42-30?

1000 miles on the crank set will have scratches and scuffs. A shop will not be able to sell the crank set as new. If you can get credit, I would request $150. If they aren't willing to go for credit then I would suggest you try selling it for the same amount.

Ana
11-15-2008, 06:59 PM
Um...

I think it's a standard triple (52-42-30). I didn't know they made compact triples! :D :p

Thanks so much!

Do I need to worry about the bottom bracket or can I keep the one I have?

SadieKate
11-15-2008, 07:17 PM
Your shop will be able to advise you on a compatible crankset with the existing bottom bracket.

I don't think you'll get anywhere near $150 for that crank. Look at ebay for comparative values. There is a brand new one on there with a starting bid of $89 with no bids. There is a used one with two bids currently about $27.

A question: why are you already changing the chain? You should be able to get 1,500 to 3,000 miles depending on how you clean/lube the chain and your size.

SadieKate
11-15-2008, 07:26 PM
You said this was a triple - is it a compact triple (50-39-30)? Or is it a traditional triple - 52-42-30?Compact refers more to the BCD or bolt center diameter which allows you to use smaller rings.

The two cranksets you mention are probably both 110/74 or 130/74 BCD (bolt center diameter), the same crank size but running different size chainrings.

Compact triples run smaller BCDs (such as mtb cranks and touring triples from Sugino and TA) and allow you to use much, much smaller rings (for instance 20-22 tooth inner ring).

http://www.sheldonbrown.com/gloss_bo-z.html#bcd

Ana
11-15-2008, 07:42 PM
I just examined them up close and the outer ring says Shimano 50-D (or 0, I can't tell which one it is) so I think it's a compact :) It makes sense since I'm such a small person and the bike is small.

I had no idea this was going to require so many details :p I'm learning new things about bike components every day! :)

I guess I'll be headed over to my LBS to ask them about it :)

Thanks for all your help :)

SadieKate
11-15-2008, 08:07 PM
Read my post above about compact cranks. A 50T outer ring does not necessarily mean you have a "compact" crank. Compact is the bolt center diameter.

There are and were plenty of standard triple cranks with 50T outer rings.

Ana
11-15-2008, 08:12 PM
I also found the original specs for my stock frame which is a Shimano 105 50-30-30 :)

Bluetree
11-16-2008, 03:23 AM
Be sure to get yourself fit/measured before investing in a 165. I am 2"
shorter than you (also with short legs) but need a 167.5 crank arm.

OakLeaf
11-16-2008, 03:47 AM
I swapped my 105 cranks out brand new and the LBS wouldn't give me a credit. I'm guessing the new one on eBay was the same story. Some LBS's will credit you when you're buying the bike new, but cranks aren't a normal wear item and they're pretty difficult to sell. I can't imagine a shop giving you any credit for a used one unless they sell a lot of used parts anyhow.

I just took the chainrings off my 170mm crankset and gave the cranks away. What I would've been able to get for the crankset brand new with the chainrings, was less than new chainrings would've cost me when it came time.

And yeah, why are you changing the chain already, and what do you mean by "regularly"???

Ana
11-16-2008, 07:00 AM
Be sure to get yourself fit/measured before investing in a 165. I am 2"
shorter than you (also with short legs) but need a 167.5 crank arm.

I heard 167.5 is hard to find so I didn't really consider it as an option :p

My geometry is such that I have to put my seat farther back than I thought but I'm sort of avoiding getting fit because I don't want to make a huge investment right now (fit = $150-$200 + components =$200-$50). Plus it's winter and my beauty is on the trainer :)

I think I would ride my bike more if it was more comfortable. The trainer is easier to be comfortable than on the road (plus I can get off at any time).

Maybe it could be my early holiday present to myself...

Ana
11-16-2008, 07:03 AM
And yeah, why are you changing the chain already, and what do you mean by "regularly"???

Oh right, that. I was advised to change it by my LBS....so I did :p Since then I researched it myself and am monitoring it (Sheldon Brown's handy 0.5" between the links) since I do not have a chain tool.

I just thought I'd mention it so you knew there would be minimum damage to the teeth :)

Cataboo
11-16-2008, 01:52 PM
I'm 5'1, 29 inch inseam, and I ride 165's. I haven't tried a 167.5, but I definitely don't like 170's - they hurt my knees.

You can sell your old cranks on ebay or via your local craigslist. I wouldn't expect to get more than $100 or so for them if that.

Crankin
11-16-2008, 02:55 PM
I've always had 165s. Also am 5' 1" with 28.5 inseam. When my Kutoa got built up, they "tried" to convince me I would become a "wild devil" and climb like the wind with 170s. One ride with those cranks, sent me right back to the shop. I felt like I could barely push the pedals. I like to spin and I guess they couldn't believe that. It took 2 weeks to get my 165s, but they did it.

Ana
11-16-2008, 04:02 PM
My inseam is about 28.5 inches too! :) I'm not a good climber and I feel like it's a bit difficult to push the pedals :p

I'll look into 165mm. . .

aicabsolut
11-16-2008, 07:09 PM
since the longest part of my leg extension is not at the bottom of my stroke.



Just swap out the crank arms. Keep the same rings, spider, and BB. Get your LBS to locate you some Shimano 165mm crank arms. That's your cheapest option. You're not going to get any rebates at the shop from a crankset with 1000mi, and selling a 105 crankset isn't going to get you much.

Ana
11-16-2008, 07:53 PM
Just swap out the crank arms. Keep the same rings, spider, and BB. Get your LBS to locate you some Shimano 165mm crank arms. That's your cheapest option. You're not going to get any rebates at the shop from a crankset with 1000mi, and selling a 105 crankset isn't going to get you much.

Thanks for the input! I was uncertain whether only changing the crank arms was an option :) They are difficult to find online :p

I always feel better knowing what I want before I go in so I don't feel like they are trying to sell me something I don't need :p

aicabsolut
11-17-2008, 08:48 AM
Yeah it's no problem. They may have to order them for you, but they should be able to do that. My bike came built with the wrong sized crankarms for the frame size, and the shop just ordered a pair in the right size and installed them. Then they dealt with the bike manufacturer about getting reimbursed (because the bike was sent to the shop with the wrong parts).

You don't even have to go with Shimano if you don't want to. I believe FSA crankarms are compatible. Maybe you'd need an FSA spider too, but your current Shimano BB and rings will definitely work. Of course, FSA will probably be more expensive, especially if you go with carbon. With a 105 crankset, I wouldn't really worry about upgrading parts of it. Either keep it the same and save cash or upgrade the whole thing. I just rode a new 105 crankset a couple weeks ago, and the thing is so flexy compared to Dura Ace or my old FSA crankset that it's not really worth the cash, IMO, to put nice crankarms on flexy rings.

As you have noticed, it may be hard to find 165mm cranksets anyway, stock. So ordering the cranks separately and sticking with the same level of componentry is probably the way to go unless you want to go all out with the upgrades. In that case, you can see if your shop can custom order you a new triple (in Ultegra or DuraAce 7800 (old DA), say) with 165mm arms or swap out whatever stock arms they can find with 165mm ones for free.

lunacycles
11-19-2008, 04:35 PM
My geometry is such that I have to put my seat farther back than I thought

Hi Ana,

Hearing this, plus the fact that you have a 28.5 inch inseam tells me a 165mm crank may not be the best idea for you.

Why do you have to put you seat further back? If it is to achieve the standard "knee over pedal spindle" position, then changing to a 165mm crank will mean you have to push your saddle back even further to attain the same position.

Shorter cranks are a good idea if you tend to ride at a higher cadence and have relatively short femurs. They can cause problems if you don't and/or if you have any front of the knee kind of pain. Just a heads up.

Also, presently Shimano offers cranks in lengths of 165 or 170mm, and no longer in 167.5mm. I don't know of any manufacturer who does offer that length at present.

Good luck whatever you decide.

Ana
11-20-2008, 04:36 PM
Just to clarify, I have to move my seat back in order to have a bearable weight distribution between my saddle and my handlebars :)

I'm seriously considering going in for a professional fit as an early Christmas gift to myself...I just feel wimpy because my endurance has been so low. I think that if I eliminate the pain and discomfort from my ride, I will be more apt to hop on my bike :)

OakLeaf
11-20-2008, 05:05 PM
Wait, wait, wait. After reading that I just re-read your original post.

"The longest part of your leg extension is not at the bottom of your stroke?" Your saddle was probably already too far back. Adjust your weight distribution with the stem (length, rise, height if you have room for more spacers) and possibly the TILT of the saddle. Depending on your preferred riding position, different handlebars might help too. Set your fore/aft saddle position to set your knee in the correct position over the pedal spindle.

You should be able to get a professional fitting done for about the same price as a new crankset...

VeloVT
11-20-2008, 05:19 PM
Just to clarify, I have to move my seat back in order to have a bearable weight distribution between my saddle and my handlebars :)

I'm seriously considering going in for a professional fit as an early Christmas gift to myself...I just feel wimpy because my endurance has been so low. I think that if I eliminate the pain and discomfort from my ride, I will be more apt to hop on my bike :)

Don't be intimidated by your fitter... you're paying them.

Otherwise, I think Oakleaf has the right take on this.

Ana
11-20-2008, 08:15 PM
You should be able to get a professional fitting done for about the same price as a new crankset...

I know, I'm just dreading the possibility of having the expense of both the fitting and a new crankset... :p

And I'm generally intimidated by fitters...I don't like someone telling me about things that are beyond the scope of my knowledge. I don't like to be misinformed and/or manipulated by sales people :( I guess they've already sold me on the fitting but I feel somewhat undeserving since I do not race or ride a gazillion miles :p

I will readjust my saddle... Thanks, Oakleaf! Back to square one I guess. Oh, I wish the pain would go away.

VeloVT
11-20-2008, 08:41 PM
So you don't deserve a bike that fits unless you race :)?

Take someone you trust with you, and don't feel obligated to buy anything that day. Then you can discuss what the fitter said with your friend and have a second opinion. I had two fittings (and I don't race, though I'd kind of like to try), and took my bf to the first one. He has no intention of ever racing but he has also had at least one fitting (he was having some hand pain issues), and I went with him. Even if you like your fitter it's always helpful to have a second set of eyes and ears.

Sorry. My bf tells me I have a habit of pressing my point a little too hard sometimes. :rolleyes:. Suffice to say, I think you deserve a fitting :D. You may learn that you have the option to spend money on new components, or make smaller modifications with what you have until you feel comfortable spending more... Alright, I'm done!

OakLeaf
11-21-2008, 03:03 AM
Where are you having pain?

I think all of us just assumed you were having knee pain because of your wanting shorter cranks... but even if that's the case, there are a lot of kinds of knee pain. Some call for shorter crankarms and some don't. As you've found, cranks are about the most expensive component that you would replace for fit reasons alone, and it definitely isn't the first thing I'd try if I wasn't sure where my problems were coming from.

Have you read through the threads about fitting in the Health section? I personally haven't read Andy Pruitt's Complete Medical Guide for Cyclists, but a lot of people here swear by that book. It would probably be a good place to start with fit questions.

And honestly... if your LBS was telling you to replace your chain every 500 miles without measuring it... OR if it really was worn to the point of needing replacement after 500 miles and they never helped you investigate why... I don't know if they'd be the ones I'd trust with fitting, either. Unless possibly you misunderstood their advice and they were telling you to take it off for cleaning??? (I don't do that either but some do...)

Ana
11-21-2008, 05:50 AM
So you don't deserve a bike that fits unless you race :)?


Yes, you are right I do deserve a proper fitting. Thank you for supporting me :D Sometimes it's clearer when someone clarifies the situation ;) :)

Well, the place I'm considering getting fit (http://www.rideboutique.com/) is not where I've ever had any service before but they guarantee their fit and they are down the street from me :) I e-mailed the fitter there and he fits up to 6 fits a week during peak season (Jan-March) and about 30% of his clients are women :) Which is very promising :)

I have since stopped going to the LBS where I bought my bike that told me to change my chain every 500 miles. I measure my own chain now :)

I guess I'm a bit traumatized by my initial experience of buying my bike and feeling like they are less than helpful. They did not really do even an informal fitting and I had insist on a fitting 8 months later when I had persistent neck/back pain (the pain I'm having trouble getting rid of. I'm also having some weird knee pain but it's difficult to pinpoint since I haven't been riding a lot).

When I went in for that fitting, I felt like they were using me as an opportunity to sell things :p I did walk out with a new saddle (which I probably needed) but I didn't feel that the person helping me get fit was very engaged. I was largely unimpressed. The only perk is that since I got my bike there, the maintenance is free so I try to bring it in annually to get it tuned up. Whenever I go there, though, I feel like they're not taking me seriously because I do not have a really nice bicycle and I do not race :p :confused: :(

I do have another LBS that I really like because they are so helpful but I am kind of meticulous and their fits are a little informal for me :p I love them for everything else but they are far away and I want a more experienced fitter.

I guess I have to mentally prepare myself to go :) It's off season though and I keep going back and forth whether I should wait until the spring :p But I'm realizing more and more that I should probably just do it :p

aicabsolut
11-21-2008, 01:29 PM
ohhh... I assumed that you were having knee pain too.

Don't buy new crankarms. Get to the bottom of the cause of your neck and back pain first. That's unlikely to be the cause of the upper body pain. If, when you are in the proper position to fix that (by moving your saddle or whatever), you start developing pain in other areas or lost a lot of power or get dead spots in your pedal stroke, then maybe it's time to investigate crank length.

If you're sitting really far back, then I'm thinking not only does your saddle need to move but so do your bars. Your bars may in fact be too high or too close to you, because by moving your saddle back, you have 1) put your feet in front of you, which helps with your balance, but 2) increased your reach to the bars by a lot. Maybe you're more hunched up than you think when your saddle is in the right place so that you're putting too much weight on your hands rather than being in a position where you are actually going to fall on your face without the bars.

So, maybe it's time for a lower or longer stem. I don't know, but your fitter should be able to help. The best part is that they are going to guarantee their work so you can go back there if you keep having problems instead of being back to square 1 and out the cash.

Cataboo
11-21-2008, 01:53 PM
I could be wrong - but I'm 5'1, use 165 mm crank arms, get knee pain with 170mm crank arms, and I usually have my saddle all the way back on the seat.

My experience with small bike frames is they usually adjust the seat angle to 74 or more degrees which makes it so that if your seat isn't all the way back, it feels like you're really sitting right over the cranks... and while short people are shorter, their femurs are usually not that short that it's comfortable to sit right over their cranks. I usually have my seat all the way back to compensate for the seat angle and I just use a shorter higher stem to bring the handlebars closer to me.

I just bought a frame with a 73.5 seat angle and I find the positioning of the seat to the cranks much more comfortable and natural.

Ana
11-21-2008, 02:02 PM
Wouldn't it be wonderful if we could tweak the geometry of our frames too? :D

Okay, so I'm dreaming big....can you blame me? :D:p;)

I will report back (perhaps in a new thread, we'll see) after I get fit :) I'm excited to get fit (except for the spending money part..) :)

If they tell me the geometry is all wrong, does that mean I can get a new bike? ;) :p I'm so drooling over those Seven Gateway Program (http://sevencycles.com/gateway/gateway.php) bikes!!!

Must...divert...attention...

aicabsolut
11-22-2008, 09:02 PM
I could be wrong - but I'm 5'1, use 165 mm crank arms, get knee pain with 170mm crank arms, and I usually have my saddle all the way back on the seat.
.

Yes, that makes total sense. However, the OP isn't complaining about knee pain, so I'm not sure the crank length is the problem. Maybe the seat tube angle is part of it. Maybe she needs to adjust her reach shorter unlike my first guess, but I still think it's more likely a reach issue causing back and shoulder pain than a crank length problem. The cranks could be wrong for her build, but I don't think that's related much to the pain issue here.

Bluetree
11-23-2008, 05:35 AM
Ana, I have to echo the posts about getting a proper fit, especially with a fitter who has access to a Fitcycle.

Like I said earlier, I'm also 5-1 and needed sub-170 cranks. I always thought I needed 165s but when I was thoroughly measured, it turns out I needed a 167.5 because of the length of my femurs. Since I was making a substantial investment at the time (Red cranks + ceramic BBs) I wanted to make sure -- and I'm glad I did!

Also, I suggest you hook up with some local cycling clubs. Their members can be a treasure trove of good information (finding the most reputable shops/mechanic, how to get parts in your neck of the woods, borrowing/trading components, etc). Most have a forum or email list that is handy to get information out. My club is a tremendous support group for me and have always responded if I wanted to try out a new wheelset, saddle or stem. No need to go it alone when working on a bike fit! ;)

Ana
11-23-2008, 07:17 AM
Yes, that makes total sense. However, the OP isn't complaining about knee pain, so I'm not sure the crank length is the problem. Maybe the seat tube angle is part of it. Maybe she needs to adjust her reach shorter unlike my first guess, but I still think it's more likely a reach issue causing back and shoulder pain than a crank length problem. The cranks could be wrong for her build, but I don't think that's related much to the pain issue here.

Yeah, I guess I have to approach one problem at a time ;) :D

Also, I'm looking into joining some sort of bicycle club. I am also intimidated by bicycle club people with their sweet bikes and speed ;) So...yeah, hopefully I'll find one this coming spring :)

VeloVT
11-23-2008, 01:24 PM
Yeah, I guess I have to approach one problem at a time ;) :D

Also, I'm looking into joining some sort of bicycle club. I am also intimidated by bicycle club people with their sweet bikes and speed ;) So...yeah, hopefully I'll find one this coming spring :)

I can so relate to this. I have been riding for almost three years now, I have a reasonably nice bike and some clothes *I* think are cute, and I"m pretty fit. But I'm still chicken to show up to one of the 2-3 club rides around where I live. I'm pretty sure I'd be able to keep up with at least the B group, but I'm totally afraid I will either be not one of the cool kids (wearing something just a little too fred, seatbag too big, something stupid like that), or my group riding skills will be judged not up to snuff (of course, that's a big catch-22 because you can't really get group riding skills without doing some group riding)...

Sigh...

It seems so much like high school.

Maybe if we try it we'll find that people are more generous and mature than we expect :cool:.