How to fix loose crank arm.

['Ross]

Hi, my mongoose pro mischief has 3 piece cranks and the non drive arm often comes loose. No matter how much I tighten it or put lock tight on it always comes loose. I think I have either grinded away part of the crank or bb. Any idea as to how to fix this? Or a good bmx shop in Melbourne that can fix it? thanks

[user name]

Can we see a pic of the arm? this will help tell what kind of setup you have, so we can advise you on it.

Try to get ole Grip to help....

[E-thugin]

by the sounds of it,, you will probably need to get a new left hand crank if its just a generic crank set..

if its alloy & u have ridden it while its loose it will wear out the crank arm..

[shmeado]

if its alloy & u have ridden it while its loose it will wear out the crank arm..

i would have to agree with that. I rode around once at my local bowl. i decideed to stop because i was tired then looked down and saw that the end nut thing had come off my LHS crank arm. i was like WTF? now i pay close attention to such details.

They are probably just cheaper cranks so you need to look after them better, or they will die on you.

[derelikt]

Get a new set of cranks from your LBS. ou could do that.

[bowzaa]

Or maybe its just the bolt...

[derelikt]

You could try some loctite on the bolt maybe?

[taylor-91]

Hi, my mongoose pro mischief has 3 piece cranks and the non drive arm often comes loose. No matter how much I tighten it or put lock tight on it always comes loose. I think I have either grinded away part of the crank or bb. Any idea as to how to fix this? Or a good bmx shop in Melbourne that can fix it? thanks

You could try some loctite on the bolt maybe?

i think he has already tried:rolleyes:

[derelikt]

I seem to have missed that bit, sorry.

[shmeado]

We all make mistakes, we're only human.

[Red Rocket]

Sounds like the interface is worn. Not really a quick fixable, unless you replace the crank/bb or both if needed.

['Ross]

thanks for the help so far, but is there some sort of putty or super strong adhesive to hold it all together? It is fairly cheap so I just want it to work and not fall apart not get outstanding performance. A mate suggested plumbing tape? has anyone else used this or know if it will work?

[BMXR']

sorry mate but theres not much you can do about it, if the bike is still under 12months old or if your really close with your local bike store, sometimes mongoose will replace it for free as it was a known problem that if you rode on it loose for even the shortest of time it would stuff it, but that also happens to most cranks. if all else fails just but a new set there about 100-150 for sealed cromoly nowadays.

[E-thugin]

Loctite do make a putty-like product... but it is fairly expensive.
it sets that hard, that you are able to drill it & machine it..

is it a square taper crank arm?? coz if it is left hand cranks only cost about $20.

[user name]

We all make mistakes, we're only human.

Or are we? im a humanoid i dont make mistakes...EVER! not raelly

[melbourne rider]

buy a new bike

['Ross]

buy a new bike

Thanks for the help, not. If someone has a cheap and simple idea to fix a cheap and simple bike that would be appreciated, if you want to say something stupid keep it out of this thread. thanks

[E-thugin]

Thanks for the help, not. If someone has a cheap and simple idea to fix a cheap and simple bike that would be appreciated, if you want to say something stupid keep it out of this thread. thanks

I dont wanna sound rude BUT.. eveyone has given you all the possible options that you can take...

i.e repairs & replacement.

20 bux is a cheap repair to me.

[julianwisbey]

use plumming teflon tape and pack it on the hammer the crank back on the spline or use electrical tape doge but it works

['Ross]

thanks thats the sort of helpful answer I was looking for, ill try it.

[E-thugin]

use plumming teflon tape and pack it on the hammer the crank back on the spline or use electrical tape doge but it works

its a very quick fix..... that will last a week if ur lucky...

u can do it if ur into ghetto repairs.. but with parts like cranks ya dont really wanna half ass around with stuff..

Harsh BUT true..

[melbourne rider]

Thanks for the help, not. If someone has a cheap and simple idea to fix a cheap and simple bike that would be appreciated, if you want to say something stupid keep it out of this thread. thanks

well what i meant is that this is all you can expect from a mongoose bmx, i have owned many ( only because i can get things cheap ) and they were all horrible bikes "unless you are just riding them to school" parts break and you end up spending more and more on repairs untill you could have just bought a good bike in the first place..

dont bitch just take it to your lbs "or use a heap of super glue so you stack"

either way i dont care

-=PR=-

[Red Rocket]

use plumming teflon tape and pack it on the hammer the crank back on the spline or use electrical tape doge but it works


Dude, I don't think you should be offering technical advice. One decent ride, and I will guarantee thats going to be f***ed by the end of it. Repairing stuff with a compressable polymer in a high stress application is just asking for trouble.

[Az]

well what i meant is that this is all you can expect from a mongoose bmx, i have owned many ( only because i can get things cheap ) and they were all horrible bikes "unless you are just riding them to school" parts break and you end up spending more and more on repairs untill you could have just bought a good bike in the first place..



Mate, buy parts and bikes that a appropriate to your riding style and maintain them correctly and you won't tend to have to many issues. Mongoose bikes arent bad, but many of these are only entry level bmx and need to be treated us such.

and FFS check your crank bolts are tight!!