Main crank freewheeling?

TempestSabre

I've an old British Eagle Mountain bike thats not had much use and I've recentlly got back on the road with it. The main crank has suddenly developed a problems. Its making odd creaking noises and then every so often its freewheeling in the wrong direction. Obviously something is failing in there. Never taken one apart before. So I'm wondering is this something I can fix myself or do I need special tools or anything?

Mucco

Creaking can be a sign of a loose crank or loose bottom bracket. By 'free-wheeling' I assume you mean it spins without driving the wheel. This is probably because it's loose. It might just need tightening (special wrench required), but it sounds like you've rounded the crank and/or bottom bracket. In which case they'll need replacing.


M

TempestSabre wrote:

I've an old British Eagle Mountain bike thats not had much use and I've recentlly got back on the road with it. The main crank has suddenly developed a problems. Its making odd creaking noises and then every so often its freewheeling in the wrong direction. Obviously something is failing in there. Never taken one apart before. So I'm wondering is this something I can fix myself or do I need special tools or anything?

TempestSabre

It only started today.

rob1891

I think that if the bottom bracket axle is rounded I think the crank would be very loose and move obviously. Also, after moving the two crank arms would no longer be in the same relative position. It is more likely that the freewheel on your rear wheel is worn out. These can be replaced, but there are a number of different types, so you'd have to examine it to find out what it is or post a photo of the wheel, removed from the bike.

If you want to remove your crank and see if there is anything wrong with it, this article gives a good rundown of what you need to do:

http://www.parktool.com/repair/readhowto.asp?id=103

The only specialized tool you'll need is a crank extractor:

http://www.chainreactioncycles.com/Models.aspx?ModelID=7963

Other general tools are described in the article.

A creak can come from the fitting of many different parts of the bike, bottom bracket -> frame, crank -> bottom bracket, pedal -> crank. Work backwards by removing and greasing the threads of each part. Though it's hardly worth the trouble as removing cranks and bottom brackets are both difficult jobs (even pedals can be a bitch!).

Rob

TempestSabre

On reflection logically it has to be the freewheel on the rear wheel. Though the creak in the crank doesn't sound good. I'll have to have a look at the rear wheel based on those photos.

Thanks for that!

scubagit

Hi There,
Speaking from experience, the creaking sound is more than likely coming from the bottom bracket. On some models the bottom bracket bearings are set in a cage for speed of assembly. What happens is, when the cage gets rusty it falls apart and generally causes havok. The bits of cage get caught in the bearings and cause wear on the bottom barcket cups themselves. It's these bits grinding together that causes the creaking. This will need to be replaced.
Now about the freewheeling problem. It would appear that the rr block is also shagged. They operate the same way as a ratchet. A small spring mounted pin causes the block to spin one way and not the other. What is happening is the pin is not engaging sometimes and this causes the slipping. More people have lost goolies by falling off their peddles from this.
Any way if the block is screw on, then depending on wear, the chain may have to be replaced and slight chance of the chain wheel too.
Both jobs will need to be done by a store as they need the proper tools.
Good luck, hope this helps.
P.s. worked in a bike shop for 6 years when I was an innocent young man. That was 13 years ago but I don't think they have changed much.

TempestSabre

Thanks for the info. Sounds like whats happening alright. Haven't had free time to get it sort yet. Perhaps over the weekend. Thanks everyone.