noisey crank
 

hi guys am new sorry if this has been asked 1000 times.use bike to get to work over last couple of weeks the crank has started to really make a grinding noise when pedling.have tried couple of diff oils and laid bike down so oil could run down through to other side but its not worked i guess its time for new crank or have u any suggestions

Are you sure it's the crank? Its most likely old chain & chainrings or bottom bracket. Descrbie the problem further? What type of noise? Can you FEEL it while pedaling?

hi well it sounds like it just needs some oil but have tried that.i can feel it grinding when i pedal as well as hear it.to start with if i sat on seat it made noise but if i stood up and used more power it wouldnt but now it makes noise whatever.if i pedal backwards its quiet or so slow that hardly move its quiet

Ok, assuming its not rubbing against your Deraillure then it probably does look like a drive train issue.
One final question. How old is the bike? Or more importantly how old is the chain and crank?

bike and all parts are about 18 months.so what do u reckon?

Worn out chain and/or chainrings on crank. If the bike wasn't that expensive (under $400 ), then I presume the parts have just worn out.

Of course I cant be sure, but if you ride the bike a lot, and its not an expensive bike my best guess would be a worn out chain and/or chainrings.

You can test chain for wear by measuring the length of it. There is a site somewhere that tells you how to do it.

link - http://www.sheldonbrown.com/chains.html.

Usually you replace the chain and chainrings together. A new chain running on old chainrigs will wear quicker then if the chainrings are new. Visa- vera with the chainring.

thx for help bike was £130 which is quite cheap it gets used every day to go to work and out and about at weekends do 20 miles a week

Dont take my word about replacing the chain/chainrings though, go to your bike shop and have em check it out aswell. Your crank could easily be loose, which would explain the 'rough' contact. To check this, give your pedals a good shake in and out, and if they wobble then your crank is loose or your bottom bracket is f****d.

first thing i checked was to c if pedals wobbled had that on old bike and they dont. will take to shop got day off work anyway cheers for your help if u ever in southend i will buy u beer lol