Durace 10 Speed Bottom Bracket
 

The bottom bracket on my new bike seems like the bearings are tight or something. It feels and sounds kind of like it is grinding. I tried to pinpoint it, but it is hard becuse you only feel and hear it when underload. If I freewheel or try to feel if there is any play it feels fine. There are no tight chain links either. Any suggestions? I will be stopping back by the shop to have them give it the once over.

If there is no noise going backwards i would think the noise would e coming from the chain. can you derail the chain and spin the cranks as a starting point.

It's possible it is from the chain since the only time I hear and feel it is underload. I can turn the crank either direction when there is no load and it seems smooth as silk.

Take the chain off the chainrings and place it on the BB shell, so you can freely spin the cranks with no resistance. Then you should be able to tell where the noise is comming from.

If it is the BB, then you may be able to overhaul it. I have done so with the older, splined version after water and grit replaced the grease in the BB. It isn't too difficult. I imagine you could overhaul the new style, but I'm not sure.


Hope this helps.
Brian

It's a new bike 1 week old so I know it's not from use. Not sure how this BB is put together.

Dura Ace 10 is sealed bearing, I believe. It sounds like a bad cartridge bearing. Get them replaced. Shimano doesn't do the greatest job with BB bearings.

People can debate all they want about pros/cons of Campy-Shimano but Campy clearly has much better BB bearings and quality. It shows in their hubs too.

I am getting DA10 soon and I just expect the BB bearings to suck. Just a given with DA.

If I had the old DA, I would just use an Ultegra BB instead of the POS DA bb.

If it's a new bike, check the crankarm bolts, chainring bolts, and pedals. All will cause creaking when loose. Also could be loose bearing "cups" or bad bearings.

Frankly, if you bought it from a LBS you should just take it back and let them deal with it. You paid too much for the bike to have problems, too much for you to fix them yourself, whether you're capable or not.