Cracking/Clonking noise when pushing hard on pedals...

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karlt
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Joined: 15 Jul 2011, 2:07pm

Cracking/Clonking noise when pushing hard on pedals...

Postby karlt » 16 May 2012, 8:24am

...bottom bracket? :(

Brucey
Posts: 39436
Joined: 4 Jan 2012, 6:25pm

Re: Cracking/Clonking noise when pushing hard on pedals...

Postby Brucey » 16 May 2012, 9:35am

pedal bearings, chain, freewheel bearings, hub bearings, bottom bracket bearings... any that are breaking up, have water in, or have had water in them and are slightly marked will likely make such a noise.

BB/pedal may make the noise if you just stand up and backpedal slowly. If it is the hub/freewheel they may be noisy (rumbly) whenever they are turning, even on a workstand.

Given the weather we have had recently, water in the bearings seems quite likely to me.... :roll:

oh, and clonking can be loose BB parts in the frame if it is once per pedal stroke, but if it is more often than that it is more likely to be the rear wheel.

cheers
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Si
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Joined: 5 Jan 2007, 7:37pm

Re: Cracking/Clonking noise when pushing hard on pedals...

Postby Si » 16 May 2012, 10:19am

knees?

crack in frame?

But I'd say Bruce is most likely right. Especially if you've a big tubed Alu frame - IME they seem to amplify any slight knocking something awful.

DevonDamo
Posts: 338
Joined: 24 May 2011, 1:42am

Re: Cracking/Clonking noise when pushing hard on pedals...

Postby DevonDamo » 16 May 2012, 10:47am

I just had this at the weekend. In my case, it was happening once every pedal stroke, so I knew exactly what it was: the nuts that hold my bottom bracket in place had loosened, so it was moving around inside the frame.

2 minute repair job - extract the crank, tighten nut up, replace crank, job done.

Chris_C
Posts: 41
Joined: 24 Jul 2009, 7:59pm
Location: Bangor, North Wales

Re: Cracking/Clonking noise when pushing hard on pedals...

Postby Chris_C » 16 May 2012, 11:44am

I had this recently too. In the end it turned out that I needed to take a 15" spanner to one pedal and tighten it VERY HARD. Definitely worth trying before you extract your bottom bracket.

noel.shearer@uuplc.co.uk
Posts: 70
Joined: 21 Aug 2007, 8:36am

Re: Cracking/Clonking noise when pushing hard on pedals...

Postby noel.shearer@uuplc.co.uk » 16 May 2012, 12:25pm

also check that your rear axle hasn't snapped. This has happened twice to me and it was only the skewer holding everything together :shock:

fatboy
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Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Re: Cracking/Clonking noise when pushing hard on pedals...

Postby fatboy » 16 May 2012, 12:32pm

Si wrote:Especially if you've a big tubed Alu frame - IME they seem to amplify any slight knocking something awful.


Do big tubed steel frames do the same? My tourer transmits noise around in a way that my hybrid does not. The tourer has a toblerone shaped downtube (520 steel) vs an "old fashioned" narrow downtube made of CroMo steel (unbranded). I find that noise from the chainset/chain etc is really noticeable in a way that my hybrid does not despite the fact that I look after the tourer and abuse the hybrid.

Anyhow back to the OP. Could be any of the following (or others too :D )

BB loose in frame (my latest clonk/creak was this)
Pedal bearings; always a prime suspect in such cases
Saddle clamp etc (does it do this only when you are seated or only when out of the saddle)
Handlebars/stem (as you tend to push/pull more on the bars)
If it is at start-up/honking I've had it that it was creaking in the seating of the gear cables in the downtube cable stops/adjusters!

Good luck!
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly