Helderberg

I have been looking at the differents offerings in the Trek line and the Cannondale line, the brand of bike I own, and found the difference in a series of bike is mostly the mechanicals. I realize this is obvious but my question is how much of a difference would a crank/chainring set offer from one model to another in a Hybrid bike? Not a road bike where ounces are king but a flat bar bike without any carbon or hidden cables but a bike of good quality. I ask as I am considering upgrading the crank and chainring set on my bike and I see that a modest up grade is only around $50.00 but to what end? Will I notice any difference or is it only a weight loss? Full disclosure, my bike is working perfectly with rear gear changes within half a crank to one third. Front gear change is at least half to two thirds but up and down are spot on. Have a little money to spend and I guess it is burning a hole in my pocket. I am looking at carbon flat bar replacement but wanted to know if the crank would be a noticeable change also.
Thanks for your patience, Frank.

DorkDisk

What specific cranks are you talking about?

Generically speaking, the best reason to upgrade a crankset is to get the gearing that you need.

After that, other improvements include: shifting quality, less weight, increased stiffness for better power transfer, and lower Q factor.

Helderberg

SHIMANO M131 Crankset (170mm, 48/38/28)

From what I can find this is the part that is on my bike. The only real complaint I have is the crank arms sweep out and I have caught the inside of my shoe on it. I have no other complaints about the piece as it is. I just wanted to know if I could expect any benefit by changing the set but you have listed the possible benefits and they really would not pertain to my riding. I will have to consider if the shoe contact is annoying enough for me to spend the money or to find a workaround. I use toe cages and really do not want to get into clips.
Thank you for your response, Frank.

hokiefyd 

You're not really going to find much of a difference between one crankset and another, especially if you're staying with square taper. Not to belittle square taper (all of my bikes have them), but it's a pretty entry level bottom bracket type today and cranksets available are generally more utilitarian than exotic or sexy. You can get some benefit by moving to a different bottom bracket type, like an external bearing bottom bracket that uses a two-piece crankset or something similar. In the square taper world, though, they'll all be more or less functionally equivalent. Like @DorkDisk said, you might change to get different gearing (going from a 28/38/48 to a 22/32/42 for example) or to a different length of crank arm...but that's probably about it.

Baboo

Helderberg

Thank you people. Message received loud and clear.
Genuinely, Thank you, Frank.

andrei_r

Personally, I would enjoy a nice new crank a lot more than a night out. A good crank will last for years and you'll feel it every single time you ride. Deore FC-M590 is an excellent choice in 3x. A bit more than $50 though.

subgrade

A couple more things to consider:

• Higher level cranksets (starting from Acera (FC M3xx), I think) have chainrings bolted to a spider, so you can replace or remove individual chainrings, thus you are able to change the gearing without replacing the whole crankset; the chainrings on lower level cranksets cannot be taken apart.
• Higher level cranksets have one (the largest) or more chainrings made out of aluminum, which means they're lighter, but wear out faster.
• Crank length may be one of the reasons for changing the crankset, but if you're happy with your current crank length, it's probably not important in your case.

dabac

Technically doable, but rarely useful.
Me, I sometimes make it work by buying rings that are on sale, and rings take less space to store than cranks.
Generally though cranks are so competitively priced compared to rings that many prefer simply to pick up a new crank when there's a sale somewhere.