REVIEWS DEALS BIKESHOPS TRAILS

Crankset

1223 Views 21 Replies 9 Participants Last post by Bikinfoolferlife, Jan 18, 2010

easybiker

Discussion Starter · Jan 16, 2010

Im doin once a while minor jumps (2-3 feet) with my bike but my crankset keep breaking
Its a hardtail bike so that could explain why it keeps breaking apart but im still pretty sure that if i put some better crank in it'll do the job
The problem is that i have absolutly not idea of what a great crankset is

Any suggestions of what crankset i should buy?

1 - 20 of 22 Posts

Bikinfoolferlife

· #2 · Jan 16, 2010

What exactly is breaking? What's your budget? My favorite value crank right now is the Shimano LX M582, Jenson has it for $99.

wildkyle90

· #3 · Jan 16, 2010

hmm yeah i mean idk whats breaking exactly, but if your actually snapping the crankarms or something serious, i also would reccomend the truvativ husslefelt

easybiker

Discussion Starter · #4 · Jan 16, 2010

Its actualy the square shape inside the arm that's causing troubles
After a while it gets deformed, the screw get loose and the arm eventualy fall off

Bikinfoolferlife

· #5 · Jan 16, 2010

easybiker said:
Its actualy the square shape inside the arm that's causing troubles
After a while it gets deformed, the screw get loose and the arm eventualy fall off

That's more likely a problem from poor installation, not a fault of the crank itself. Square tapers work great when installed properly. Once they're deformed, though, it is time for a new crank. The nice thing about the crank I mentioned is it comes with a new bottom bracket as well. If you just try to buy a new square taper crank you'll have to make sure it works with your current square taper bottom bracket spindle length.

easybiker

Discussion Starter · #6 · Jan 17, 2010

That's more likely a problem from poor installation, not a fault of the crank itself. Square tapers work great when installed properly.

I dont think its the installation the problem 'cause the first time the crankset broke (i'm at my 3rd one right now:madman: ) its the guy at the bike shop who changed it and it didnt make a difference. Even more when i changed it, i replaced it by the same model
And what do you call a good installation???

kapusta

· #7 · Jan 17, 2010

easybiker said:
I dont think its the installation the problem 'cause the first time the crankset broke (i'm at my 3rd one right now:madman: ) its the guy at the bike shop who changed it and it didnt make a difference. Even more when i changed it, i replaced it by the same model
And what do you call a good installation???

What crankset do you have now?

easybiker

Discussion Starter · #8 · Jan 17, 2010

kapusta said:
What crankset do you have now?

I cant remember the exact model but i know its an unexpensive shimano
It doesnt really matter because now its dead

CaveGiant

· #9 · Jan 17, 2010

I think SLX is the cheapest cranks rated for abuse.

I used Raceface Atlas and it has taken 3 years to break, but has lifetime warranty =-)
Just to put this in perspective I have broken EVERYTHING else on my bike, the cranks was the last to go, EVERYTHING.

random walk

· #10 · Jan 17, 2010 (Edited)

Are the spindles on the BB sound? Seems to me if you keep experiencing the same failure, the crank-spindle interface is compromised. My guess is your crank bolt is coming loose, followed by damage to your crank (and maybe the spindle too).

FWIW, I had a crank bolt come loose on a ride, on my (at the time) 15-yr-old Stumpjumper. A little Blue Loctite prevented that from happening again.

edit: To be clear, don't take that to mean "put your damaged crank back on your possibly damaged spindle and use Blue Loctite"

kapusta

· #11 · Jan 17, 2010

easybiker said:
I cant remember the exact model but i know its an unexpensive shimano
It doesnt really matter because now its dead

If it did not matter, I would not have asked in the first place. Do you want help with this or not?

Anyway, it does matter what you have now, because knowing what does not work will help determine what will. If it is a very low end, budget/entry level crankset, then simple buying any half decent set could solve the problem, but if you are breaking a set of quality square taper cranks, then you may need something for freeride-specific.

Also, do not dismiss improper installation. It is possible that the problem is with the bb spindle at the bb/crank interface being deformed, and that is often due to improper intallation (specifically, the torque on the crank bolt). Once that is deformed, putting a new crank on is just going to damage the new crank at the interface. Based on the limited info you are giving, I am going with a deformed bb interface as the source of your problems, and that is either a factory defect or improper installation.

Really, any halfway decent set of xc cranks nowadays should handle an occasional 2-3 foot drop with no problem unless you are very heavy (something else you have not let us know yet). The suggestion of the LX cranks for $99 sounds like a great idea to me:thumbsup:

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easybiker

Discussion Starter · #12 · Jan 17, 2010

kapusta said:
Also, do not dismiss improper installation. It is possible that the problem is with the bb spindle at the bb/crank interface being deformed

So basically if the bb interface is the problem i gotta change the whole crankset?

Sorry for the "limited informations" i gave you
My budget is around 100-150$ and im not super heavy so i think i'll buy the Shimano LX
except if you have a better suggestion

Ken in KC

· #13 · Jan 17, 2010

No...

easybiker said:
So basically if the bb interface is the problem i gotta change the whole crankset?

Sorry for the "limited informations" i gave you
My budget is around 100-150$ and im not super heavy so i think i'll buy the Shimano LX
except if you have a better suggestion

What he's saying based on what you told us:

1. You're rounding out the inteface between the crank arm and the bottom bracket.

2. You've replaced the crank arm 3 times for the same problem.

3. You really shouldn't be having this problem.

4. You never mention replacing the bottom bracket.

5. You still haven't answered the questions asked.

It sounds like improper installation because it seems like your bottom bracket needs replaced. If your shop has replaced the crank 3 times and each time you have the same problem and they haven't suggested a $30 bottom bracket replacement, shame on your shop.

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kapusta

· #14 · Jan 17, 2010

easybiker said:
So basically if the bb interface is the problem i gotta change the whole crankset?
[/QUOTE
Yes, if the bb spindle is deformed, then you need to replace the bb, and if it has already damaged the current crank arm, then that also should be replaced.

Sorry for the "limited informations" i gave you
My budget is around 100-150$ and im not super heavy so i think i'll buy the Shimano LX
except if you have a better suggestion]

Click to expand...

Yes, that sounds like a good idea:thumbsup: It even comes with the required bb.

FWIW, I agree with the comment made that your shop really screwed up not replacing the bb after the 2nd arm fell off. That should have been a heads up that there was definitely a problem with the crank/bb interface.

motoxkfx123

· #15 · Jan 18, 2010

this is what i did run the race face diabolus you will not break it or there is the shimano saint also bullet proof.

Photobucket

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easybiker

Discussion Starter · #16 · Jan 18, 2010

Ok the LX seems to be the most suitable for mu budget (100-150$)
But i remember when i previously searched on the inter for a crankset that there're 2 types of shape on the last gear (the one facing the inside of the bike)
One is curved and the other is not
Will that be a problem?

To be clear, don't take that to mean "put your damaged crank back on your possibly damaged spindle and use Blue Loctite"

For the blue loctite, i already tired a similar product and it didnt work

It only stopped the "squeeking" sound

Bikinfoolferlife

· #17 · Jan 18, 2010

easybiker said:
Ok the LX seems to be the most suitable for mu budget (100-150$)
But i remember when i previously searched on the inter for a crankset that there're 2 types of shape on the last gear (the one facing the inside of the bike)
One is curved and the other is not
Will that be a problem?

For the blue loctite, i already tired a similar product and it didnt work
It only stopped the "squeeking" sound

Two types of shape for a granny ring? There's different sizes, in terms of tooth count, but they're all round.

easybiker

Discussion Starter · #18 · Jan 18, 2010

Bikinfoolferlife said:
Two types of shape for a granny ring? There's different sizes, in terms of tooth count, but they're all round.

Yeah thanx man i knew about that:thumbsup:
What i mean is the shape of the last gear will modify the distance between the crank and the bike

Also something i forgot to ask:
The speed? This LX is a 7, 8 or 9 speed?
It think my bike is 7

Bikinfoolferlife

· #19 · Jan 18, 2010

easybiker said:
Yeah thanx man i knew about that:thumbsup:
What i mean is the shape of the last gear will modify the distance between the crank and the bike

Also something i forgot to ask:
The speed? This LX is a 7, 8 or 9 speed?
It think my bike is 7

Are you thinking about chainline? It's not the shape of the gear, it's the specific setup of the crank/bb. An external crank is typically 50mm chainline, older square tapers more likely 47.5mm; the change is not likely going to be noticeable but possible. The LX is a "9 speed" but it'll work fine with your 7 or 8 speed chain.

CHUM

· #20 · Jan 18, 2010

just buy my Saints for $80.....they won't break....

outboard bearing included....

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