Crank tapping noise

by Blackstone   July 28, 2011  

Hi guys,

after years of loving cycling i finally got myself a 2008 Trek 1.2.

It had only limited use when i brought it and i've done 450 miles.

I have noticed a tapping noise when i put pressure on the peddles, mainly the left hand peddle.

I'm not a bike techy yet so not sure on the cause or possible remedy.

Any help would be greatly apreciated

Cheers

Glen

14 user comments

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Have you checked if your pump is hitting the crank...that used to happen to me about once a year, I'd forget why it had happened the time before, and spend an inordinate amount of time looking at my feet. Come to think of it, this was on a 1200D, the predecessor of the 1.2.

It can happen when you apply more pressure because you bend the crank a bit (so doesn't show up when you spin the pedal by hand). There are other things down there that can tap, like the bit of cable jutting out of your front derailleur.

posted by bazzargh [137 posts]
28th July 2011 - 15:50

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Thanks for replying bazzargh,

gone through all that, its not my pump and no cables it could be.

I can ride along casually and not hear the noise. As soon as a put the power down, climb a hill or get out of the sadle i get the tapping on the left peddle.

wondering if everything is as tight as it should be down there?

Glen

posted by Blackstone [38 posts]
28th July 2011 - 16:00

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Could be your bottom bracket isn't as tight as it should be - I had the same problem with my Trek last year. Apparently they work loose really easily when brand new, especially if you've been riding lumpy roads. Pop back to the shop and ask them to take a look, unless you've got the right tool to tighten it up yourself.

posted by griffinvulture [2 posts]
2nd August 2011 - 12:42

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Cheers Griffin,

I was working on the theory that that was the case.
Might get myself the tool and tighten it myself.

Probably due a service so might just do that Smile

posted by Blackstone [38 posts]
2nd August 2011 - 14:05

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Bottom Bracket or a pedal bearing would be my guess. If you apply pressure (ie. weight) to the pedal, then there may be a tiny amount of play in the bearing which is causing the clicking noise.

If your bottom bracket is creaking or clicking, then apply some plumbers tape (PTFE Tape) to the bottom bracket threads before re-inserting it. This eliminates any slight movement in the threads which might cause the sound.

posted by Barneyballbags [32 posts]
2nd August 2011 - 16:58

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Had the bike serviced and they said everything is/was all tight and as it should be down below.

Not had the tapping noise since the service so they must have done something to sort it!

Cheers

posted by Blackstone [38 posts]
7th September 2011 - 12:24

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i had a prblem with a Trek 1.7c i had the tapping noise from the bottom bracket, i then took it to my local bike shop and they found that the left side of the BB shell hadnt been faced off properly allowing the cup to move sligthly , once this was rectified it stayed tight.
Hope this helps

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posted by andrew miners [46 posts]
8th September 2011 - 10:51

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I had a similar problem once and had to take the bike to bits to find the problem. turned out to be a headset spacer :-S

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posted by Dave Atkinson [6974 posts]
8th September 2011 - 12:34

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Hi guys and gals,

Tapping problem returned in the bottom bracket.I dont feel any movement through the peddles when the tapping is happening.
I dont want to leave it so that something gets damaged down there so i was thinking about changing the bottom bracket.
But, i dont know firstly what i've got, what i would need to get and how to change it?

I've a 1.2 Trek 2008

Any advice for a bottom bracket novice would be greatly recieved!

Many thanks

Glen

posted by Blackstone [38 posts]
18th February 2012 - 12:32

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Check your chainring bolts are tight- mine were loose and causing a lot of creaking on my bike...

posted by samg123 [16 posts]
18th February 2012 - 13:01

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check the pedals as well...

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posted by Fringe [1079 posts]
18th February 2012 - 13:16

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Just been and checked. Chainring bolts tight but left hand peddle bolt slightly loose
Tightened it so I'll see if it was that when I'm next out

Cheers

Glen

posted by Blackstone [38 posts]
18th February 2012 - 14:48

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I had a tapping noise on my bike last year, I only heard it when I put pressure on the pedals, mainly hill climbing. It only tapped when I moved the pedals around too. It was annoying. The local shop couldn't find anything. Anyway, I took it out in the rain one time, and I've never heard the noise since!

posted by humpyg [15 posts]
21st February 2012 - 12:31

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also to throw something in the mix, it could be your seat/post. i have had this before, the noise seemed to be crank/pedal based but turned out to be an issue up top!

posted by russyparkin [546 posts]
22nd February 2012 - 15:21

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