A funny crunching in my BB

paul.skibum

New built bike, faced BB and tapped threads, new Hollowtech II BB with deore cranks, new DX spd pedals.

Riding along I can feel, primarily in my left foot a kind of gritty graunch at the same point every rotation (about 5 O'clock in the left foot rotation). I can feel it in right foot too but not so pronounced so I am guessing the problem is somewhere on the non drive side.

Gritty noise goes away if I am pedalling quicker but with less effort comes back if I am putting forces in at slower speeds.

Any thoughts?!

I'm probably going to drop the BB back out, clean the BB threads up, apply some more grease to pretty much everything and try again other than that I have no clue!

Anonymous

could also be the pedal bearings or pedal threads.

nicklouse

work your way through the parts.

is it the BB? is it the hub? is it the pedals? is the chain catching?

paul.skibum

pretty sure its not the chain - too specific a point in the rotation

pedals - I tried back pedalling or changing the angles and pressure with no effect

I think it is hub or bb - strip down this weekend hopefully

Turrican

Is the bb tightened correct and also are the right spacers on and is the arm correctly flush on the drive side spindle, the bit that goes through the BB it should have 2 bolts to fasten and one cup to tighten up on the non drive side arm. Use the Hollowtech 2 bb cup tool to make sure the cups are tight as oi got newish ones on and started making a noise when put power down and i tighten the bb cups up a smidge.

BigStu2

I had the same problem. Had the BB faced and it then appeared that all I needed were washers fitted between the pedals and the cranks, once fitted it runs sweet no more noise.