Bike Problem - what is it?

AlanD

I have an almost new bike.....aluminium frame, hybrid style, bottom end of the bike range meaning it wasn't expensive, so expected some problems.

First problem that cropped up is the pedals or maybe the crank between the pedals. When I push hard....say going up a hill, I hear a knock from the pedal. It's hard to pin point, but I think it's from inside the crank housing. You can feel this knock on every revolution too. Any ideas what it is? Just want to be able to either fix it myself or know what to tell the shop who will fix it for me.

Other issue.....there are 3 cogs on the front. I have a quick shift shimano shifter but when trying to go to the inside cog it never goes. I have to kick chain in with my foot. If I adjust the mechanism that moves the chain down to the inside cog, will it affect how the chain gets moved to the outside cog?

Your help would be greatly appreciated.

Ciaran500

I had a similar problem with my bike when I got it new. The big bolt in the centre of the crank had started to come loose and the gear were wobling and banging off the derailer on the front. It was a simple fix for me, just get a big allen key (8mm) and tighten it.

The sencond problem is another simple fix. There will be two screws on the derailer that adjust how far it moves. Turn them a little bit at a time till its right. This can be a frustrating job as when you fix it for one gear another one can be off. Just keep at it a little bit at a time and you will get it.

Ghost Rider

The problem could be in the crank bearings or in the bottom bracket. If it's either, the relevant part will probably need replacing.

The person in the repair shop should be able to establish this, but I have found that crank bearing problems can go unnoticed by professional mechanics. I think it's because simply rotating the cranks on a workstand may not put enough pressure on them for the problem to be audible. Taking it for a cycle might be the only way to establish it.

First problem that cropped up is the pedals or maybe the crank between the pedals. When I push hard....say going up a hill, I hear a knock from the pedal. It's hard to pin point, but I think it's from inside the crank housing. You can feel this knock on every revolution too. Any ideas what it is? Just want to be able to either fix it myself or know what to tell the shop who will fix it for me.

Morgan

It's almost impossible to tell what the knocking sound is without hearing it - there are several possibilities.

Adjusting the front mech is easy though - details here:
http://www.parktool.com/repair/readhowto.asp?id=75