I'm not actually sure what the problem is..
 

..but i'm gonna bore you all with my unknown problem.

So not last Tuesday, the tuesday before, I bought a Raliegh Explore from Halfords in England, only to return it for repair the following Saturday (because the pedal practically fell off) for repair. The guy replaced the entire bottom bracket with a new one (sr suntour i think).

Anyway, being the happy chappie I was to get it back (yesterday), I took it for a big ride around town for like 3 hours today and when I got home, I realised that the left crank arm was super loose. Looking down, it appears (NOTE: I have no idea what part I mean here) that a metal cover was protruding between the crank arm and the frame. I'm only a bike n00b so I have no idea what the problem is here. The metal cover thingy is also cracked on closer inspection.

Should I attempt to repair this myself? If so, how? I can't be bothered wheeling it all the way across town back to the store for another repair..

Any help would be much appreciated,
Tom :)

EDIT: It turned out it was the 'cup' that was cracked and was protruding.

YOu need to take it back. You'd need a crank puller and a bottom bracket tool to fix it. And that's only if something isn't cracked as you said. Not sure what you mean by the "metal cover". It looks like your bottom bracket, or the bottom bracket retainer is coming out. Since they (supposidly) replaced it, they should fix it/replace it free. Again. Don't ride it though.

Is Halfords a bike shop or a toy store?

I'm making the assumption that this was a new bike when you bought it, not used. Is this correct?

I think the guy has demonstrated that he has no business touching a tool to a bike. Any half-competent bike mech should be able to tighten a pedal or replace a bottom bracket. Having ridden it for a bit of time with the bottom bracket flopping around, I hope the frame has not been damaged. If the frame has indeed been buggered, the frame or the whole bike should be replaced.

If this problem is a result of a cracked or broken frame, or if the frame is cracked as a result of a faulty repair, you deserve a replacement bike. If by "metal cover thingy" you mean the part of the frame that the bottom bracket screws into, the frame is not practically repairable.

As has been discussed here many times, the most important difference between buying a bike at a reputable dealer and a toy store (I don't know what kind of store this is) is having a bike that is properly assembled in the first place and being able to get service and support, should there be a problem with the bike.

At this point, the only reason I would go back to Halfords would be to return the demand my money back. IMHO They have demostrated that they likely don't assemble their bikes properly and are not capable of supporting their products.

My choices would be;
a. take the bike back, demand a refund and buy a bike elsewhere. or,
b. forgo any warrantee Halfords might offer (because it ain't worth beans) and take the bike to a reputable dealer to be fixed properly and inspected for roadworthyness.

Was it a plastic or metal bottom bracket sleeve?...

Halfords are Britains "leading" car accessories & bike retailers. They may as well be a bloody toy store though!

It was the 'cup' that was cracked.

I had to walk all the way down there again after I made that post and they took it back in for repair. I regret doing that deeply. I'm a big softy at heart and I know I shouldn't take any crap from them anymore.

Get this though - The first time I actually bought it, I had to return to the store twice because they "loosen the components so customers can fit the bike into their car". Fair enough, but it would be much easier and safer if they'd have actually told me this prior to me hurtling down the main road outside. They didn't even bother pumping up the tires!

If you ever hear of anyone thinking about purchasing cycles, no, anything from Halfords in England, give them a slap for being silly.

Their puncture repair patches are good though! "loosen components so customers can get it in their car"?! Sounds like a recipe for disaster to me. I'll go to my local halfords and throw a brick through the window for that.

Hahaha you should. I could have really broken my neck thanks to that tomfoolery.

Thanks for all your help, incedentally, you've made a new member into the biking community feel very welcome and (if my bike stays fixed) I'll definetly be coming here for help again.

By the way, the guy said he'd ring me tomorrow to tell me when my bike will be ready - do you think I should tell him to take a good look at the frame, cause that may be the cause (according to some research i did on the net).

I'm not sure whether halfords would let you do this, they probably wouldn't want you see all the mistakes they make, but some bikeshops don't mind if you hang around while they fix your bike, great for learning the basics and checking they're tightening everything they should be.