Crankset change--advice appreciated!

[Ana]

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]

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]

Um...

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

Thanks so much!

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

[SadieKate]

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]

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]

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 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]

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]

I also found the original specs for my stock frame which is a Shimano 105 50-30-30

[Bluetree]

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]

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]

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

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]

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 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]

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]

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]

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

I'll look into 165mm. . .