Clank sound after 10 miles

[litewerx]

[attachment=5352]I hope someone has run across this before. I have a Giant mountain bike and I have been using it on the paved trail a lot lately. Recently, I began hear a clanking sound after I ride about 10 miles. Sounds like when a pedal hits a kickstand that isn't all the way up. I can't duplicate it on a bike stand. It doesn't start until 10 miles and after 15 miles, I get an added rubber squeaking sound on top of the clank. The noise happens in the same pedal position every time and particularly when I'm pedaling hard and hardly at all if I pedal lightly. I had the derailleurs and sprockets cleaned recently. Any ideas? Thank you.

[cny-man]

Once per crank rev can't be anything with derailleurs or rear wheel in this case. "Sprockets" is not specific - rear is cassette/freewheel or cogs, front is chainwheels, but the most likely candidate is a loose tightening ring for the bottom bracket, the other less likely being a bad bottom bracket. Get the tool for tightening the rings, then back off the left side, tighten the right side, then retighten the left. Be sure to properly tighten the crank arms and pedals afterward as well. If the problem persists the BB is probably bad.

[litewerx]

Thank you for the correct terms and advice. I will look for a place to purchase the tool and give it a shot.

(09-11-2014, 11:15 PM)cny-man Wrote:  Once per crank rev can't be anything with derailleurs or rear wheel in this case. "Sprockets" is not specific - rear is cassette/freewheel or cogs, front is chainwheels, but the most likely candidate is a loose tightening ring for the bottom bracket, the other less likely being a bad bottom bracket. Get the tool for tightening the rings, then back off the left side, tighten the right side, then retighten the left. Be sure to properly tighten the crank arms and pedals afterward as well. If the problem persists the BB is probably bad.