pgjackson

My bike is making a grinding/scraping noise on the downstroke on both sides. If I coast and pedal lightly the noise stops, When I start applying pressure to the pedals again the noise comes back. Does this sound like a BB issue?

Bigbus

Try wiggling a crank arm and then the pedals. If nothing wiggles (no play) then I would be looking at the chain and cassette. Have you lubed the chain lately?

pgjackson

I recently got it back from a full tune-up at the LBS. I assume they lubed everything up. But you know what they say about assuming... I'll oil the chain again just to make sure. It only makes the noise on the down stroke.

Bigbus

Other's may chime in here and correct me, but I would be really surprised if a bike shop included lubing the bottom bracket, hubs, or headset in a tune up. My experience has been derailleur adjustment, brakes, and if you're really lucky, chain and cables lubed and checked for wear. I should add, they might check wheel true, but that will be an extra charge if needed.

If it's the Rossetti you probably have sealed bearings.

Chandne

This was happening to me so I changed the BB from the plastic Shimano one to a Works with angular bearings. Noise gone, thankfully! I was rather sure it was the BB. I lube the chain often and clean the pulleys. The chain was good, and the rear derailleur was rather new. The noise was coming more when putting down power on the uphill, so I was pretty sure it was the BB.

Outrider1

In my experience, that's indicative of the bottom bracket. I do know from another post that the OP just had the bike thoroughly gone over though if I'm not mistaken. Could be a myriad of things not tightened or overly tightened. I'd take it back to the shop and have them look at it.

Kimmo 

What sort of BB? How much wear on the chain?

pgjackson

Well, it turned out to just be a dry chain. Lubed it up, put a couple drops between the cranks and BB, and it's just about silent now. I guess it just shows that sometimes those LBS tune ups aren't very thorough.

veganbikes

At least at my shop a lot of the techs are huge fans of Triflow which is way too light of an oil to be using for chains ATMO. Your shop could be in the same boat. I prefer to use wax lubes or a wet lube personally but especially for customers who may not lube their chains often.

pgjackson

I just used Finish Line Dry Lube.

zymphad

I had the same. I had some dude telling me it was cause chain was rubbing on the FD due to frame flexing. Yeah that was BS.

I took the crank off and tightened up the chainrings and replaced the BB Bearings, they were 3 years old. Grinding noise stopped. He was right the chain was grinding on the FD, but not because of frame flexing.

Edit: Glad you fixed it.

zymphad

Not at home so don't know brand, but it's a blue can. It cleans and lubes at the same time. I'm lazy that way but it's worked out really well, chain does look clean and lubes really well.

pgjackson

Yeah, my first thought was that the FD was rubbing (that was a huge problem when I had Sora triple on my first road bike). I kept a close eye on it and the FD was dead center and there was no flex of the frame. I guess sometimes it's the simple solution that gets the job done. "Have you lubed it" is the biking equivalent of "have you rebooted your computer".

veganbikes

You cannot really clean and lube well. Degreasing agents don't play well with lube hence why we use degreasers and then we wipe off and use lube.

I am curious what they are using. Jeff Bezos sells a 55 gallon drum of sex lube that is blue and there is a smaller spray lube for motorsickles and Finish Line makes a bike product that you can spray which they claim is one step but was mentioned above as not really working.

The cleaner is going to remove the lube so how exactly can you now in the same spray also lube with a cleaner?

Bigbus

I'm OCD about waxing my chain. I even dip parts like spare cassettes, sprockets, you name it if I'm just throwing them in the parts bin and don't want them to rust. But all BS aside, I enjoy waxing my chains. It's like down time and very relaxing. While I wait on the wax to melt in the crockpot I will put on some tunes and shoot a few games of pool. It's all good.