My crank arms seems a bit loose, and its hard to catch speed on it (fixed gear). How can I fix this problem? I checked my friend's fixie and his crank arm is tight and doesn't budge if you move the crank arm left to right. While my crank arm it can be moved left to right like 3 cm which is a sign of looseness. Help me please!!

edit: I've retracted my response. LoRoK is right.

Take your bike to a shop. You clearly have no idea what's going on with your bike, or how to maintain and service it, and therefor there could be a multitude of problems besides your crank moving 3cm.

I don't have the money to take my bike to the shop

Well then, you're screwed.

Assuming you mean looseness of the arm on the spindel and not of the BB
If you really have to do it yourself you probably need to tighten the fixing bolt should be either an allen (8mm?) or a 14mm socket. don't tighten it down too far though, although your crank may already be ruined from riding it loose, cranks are made from aluminum and they sit on steel spindels which will deform the arms quite easily if mishandled
Read this before attempting any maintenence, also verify that your crank arm is moving independantly of the oposite arm (the loose one moves and the other does not) if they both move do not tighten the fixing bolts
https://www.sheldonbrown.com/tooltips/cotterless.html
This all assumes you have a cotterless crankset
edit: afterthought, just read the entire https://sheldonbrown.com/fixed.html article
"and its hard to catch speed on it (fixed gear)"
I don't really know what you mean but if your saying what I think your saying (can't go fast enough) you need to change your gear ratio.

Reading through your post again I'm actualy not sure what kind of looseness your talking about if theres a nice LBS around your area take it in and see if they will diagnose your problem for free, they might.

Maybe he meant 3mm?

Haha, awesome!

LoRoK, you should think about learning how to communicate if you're going to litter these forums with you thoughts.

Apparently you don't know the definition of communicate.

You might get better results reposting this with a more detailed description of the problem in the mechanics section

I'm willing to bet the looseness you're experiencing is chain slack, and has nothing to do with your cranks. To check if your cranks are loose on the bottom bracket spindle, you would try and force them towards each other (ie, push them both downwards), if you feel any play you have trouble. I'm willing to bet this is not the case and that what you're dealing with is a loose chain.


You other guys that offered nothing but condecension suck. If you monkeys knew basic bike maintenance yourselves you'd have been able to give him a starting point to diagnosing his problem within 2 minutes

I guess this could also be your problem, more clarification really is needed before we can help you, but as I said you would have better luck in the mechanics section

Then you definitely don't have the money to buy a replacement crank if you've rounded that one out by not keeping it tight. Take it to a local shop and tell them what's happening, explain you're on a budget, and see what they suggest. If it's just tightening your crankbolt, they can probably tighten that for a minimal fee, if any.

Of course, you can tighten your crankbolts as well.

tighten BB, tighten cranks, fix ur chain tension, retighten ur pedals. If it's still broken, it's ur goddamn bb.

Apparently I should apologize here. I was wrong to want the OP to have a bike that worked and wouldn't be at risk of some sort of failure that could injure him. I was further wrong to consider that I didn't have full knowledge of the problem, thus recommending him to visit a professional that could help him; when instead I personally should have picked any one of a myriad causes for a problem I don't understand for him to monkey around with, regardless if that would actually help or in fact make matters worse still. I'm such a jerk.

Can I use this for my sig?

Actually, I think elTwitcho is probably right. My guess was a slack chain, but I fail to see how that will affect the OP's speed. To make matters worse, the OP has utterly failed at communicating what his issue is. A crank can turn forward and backward, and wobble side to side. "Left to right" is pretty damn vague.

You own and ride a bike. You have no money to bring your bike to a shop, yet no knowledge of bike repair/maintenance whatsoever. I'm assuming you don't own any tools, let alone proper ones. Did you really think you'd be able to ride your bike for your whole life (or at least until you lose interest in it) without ever needing to tighten a bolt? I'm not trying to be mean here but come on!

One piece crank - right?

If that's the case, there will be a locknut and a cone on the left crankarm. They'll be a left hand thread. Tighten the cone (closest to the bike) until the crank stops wobbling but still turns smoothly. Then tighten the locknut up against the cone.

Good luck.




Incidentally, the other posters, while rude, were right. Learning to communicate clearly is a useful and necessary skill to learn. Your original post doesn't provide very much information to work with.

Everyone's bike is at risk of some kind of failure, it's called riding a bike. You just didn't want to help and while you might be comfortable with never learning how your bike works beyond understanding which end faces forwards, there's no reason to discourage other people from bettering themselves.

And your whole melodramatic "I was rude to him because I want him to be safe!" Crap was ridiculous, give me a break. There's no reason why your belief in not learning about your own bike should translate into rudeness, so give it up

Why do you put those bikes in your sig if you don't own them?

^ I thought that same thing when I commented on one of them in another thread.

Says the guy riding the creamsicle.

Since when are Creamsicles glittery gold? At least the bike in my sig is my bike.

I see more orange than gold. You need new grips.

20+ posts. Epic troll win?