Grinding sound when pedalling

[oaep7]

Only happens when pedalling though...

 

[We_are_Stevo]

Yes, because you're pulling on the bars! Try pedalling with no hands (don't blame me if you fall off and break something though ) and see if it still does it...

...that's why the creaking saddle was suggested; happens more often than you would think!

 

[Skinwhistle]

Have you checked the frame for cracks?? Not the question you want to hear! But better safe than sorry?!? :?:

 

[Woz]

Does it make a noise in every gear?

For example, smallest sprocket, middle ring the chain could occasionally catch on the shifting pins on the big ring when putting the pedal down.

Sometimes, new drive chain components just need to bed in; put a cassette in the Walkman and just ride a few x00 miles.

 

[FluffyChicken]

Dodgy Breathing ?

 

[oaep7]

Been out doing some testing, problem is just when in the middle chainring - inner and outer totally fine even sprinting up hill. Looks like the chain isnt freeing properly from the chainring after the downstroke which makes it chainslap the chain stay.

Time for a new chain?

 

[kaiser]

Have you checked the chain? Do you know about measuring it? If you use a rule and measure between pins 0 and 12" should line up. I.E if you measure between pins and its 12 1/8" your chains fecked.

 

[azaro]

Now thats probably more like it - haha!

+1

Make a small incision with your favourite multitool, apply a liberal squirt of WD40 into the gaping wound, spit on it, then apply a Parks puncture patch and you're done. Leave the patch on for 3 days, then remove. You won't even see the scar.
Trust me, I'm a doctor/engineer!

 

[oaep7]

Resolved!!

After some more testing / investigation it turned out to be a worn middle chainring hooking the chain up and causing the chain to jump and grind.

After inspecting the new ring to old it's like night and day.

Cheers all.