Hi there,
I'm new to these boards. Been lurking here and there and decided to register as had a recent problem with my bike.
Had it for about a month after becoming interested in fixed-gear bikes, newbie you could say, i suppose, so my knowledge of mechanical aspects is limited.

But anyway, last time i was using it, after a friend had been on it, I noticed the left crank arm was loose, not at all tight.



The image on the left shows the arm when it's at it's loosest, moves around and almost feels as if it's about to fall off (don't want to try taking it off). The image on the right shows the arm when i've pushed it in as far as I can (with my hands), it's less shakey but still loose.
Not sure how to tighten it, guessing it may be these two holes at the end..



So yeah, is that where the problem is, do I need to tighten these two holes with a special tool?
I plan on visiting the bike shop tomorrow to ask/borrow tools, but wanted to ask here and know what to expect of them.

Apologies for such a long-winded post over something that may turn out to be so simple.
Thanks in advance.

The thing with two holes looks like a plastic dust cover, pull the cover off then you'll be able to tighten it up.

If it is loose, do not ride it until fixed or you will have to buy a new crank arm/cranks.

+1. do not ride it at all. alloy cranks are soft and the bottom bracket axle will irreparably damage the crank.

+1

Take of the black plastic dust cover with the two holes - use any old thing to get if off like a knife or pen stuck into one of the holes and gently tap it around with something else like a rolling pin or book.

Under this you will see a crank bolt or some description - tighten it up.

DO NOT RIDE YOUR BIKE WITH THE CRANKS LOOSE LIKE THIS, EVEN TO THE BIKE SHOP !!!

+1

Remove the black dust cap with a pen / nail and do up the bolt inside. Usually a 15 mm sometimes a 14 mm socket will do the job.

Do not ride this bike even for a short distance or you will require a new crank.

you probably already need a new crank

Do some skids!

This is bad advice - I experience what could happen from skids + sketchy cranks first hand.

http://www.recycle-y-bike.org they will help you out

[COLOR=#008000]www.recyke-y-bike.org sorry[/COLOR]