gquirk77

My Salsa Fargo is making a grinding noise when I pedal hard and a popping and grinding when I'm not pedalling. If I'm lightly pedaling on a flat area it sounds fine. I thought it was the bottom bracket so I had a new one installed but it didn't fix the problem, so next I had new pedals put on and that's not the cause either. Sprayed some WD 40 and that helped for about 4 miles with the noise that happens when I'm pedalling hard but didn't do anything to the noise when I'm coasting.

I'm in Sardinia and don't speak Italian, the mechanic didn't do much (any) troubleshooting, he just installed the 2 items and when neither fixed it i didn't go back a 3rd time to him. I stopped at another mechanic type place that sold kids bikes and other sporting goods and the guy there thought it was the rear wheel (but our conversation was mostly hand gestures because he didn't speak any English and he was abrupt), but how could it be the wheel when the 2 issues are both dependent on if I'm pedalling or not? Plus, the sound doesn't seem to be coming from the wheel, sounds like it's at the bottom bracket area.

Everything is closed tomorrow so I'll have to wait till Monday to find a bike shop.

FBinNY 

The key to effective diagnosis is ISOLATING the issue.

Of course, I'm not there to hear it (though gladly would go if you paid the fare), but I suspect that you may be dealing with 2 unrelated issues. When some "grinding" (sort of) noise isn't all that rare when pedaling hard with worn chains or sprockets. Lubrication often helps, but won't eliminate it entirely.

The coasting noise is most likely coming from the wheels, or more likely, the freehub/freewheel.

So, getting back to isolating.

1- Lube the chain, and see if it changes anything for under load.
2- hang the bike and spin the rear wheel with the chain disengaged, (if you can safely hang the chain with some wire ties or bungee) try coasting down that hill with no chain on the rear sprockets. No grinding now, points the freewheel or freehub itelf. If it still grinds, it's the wheel bearings (front or rear).

Of course, other factors might be involved, line tire noise on pavement, muffled by the bigger chain noise under load, and now audible when coasting. So, do the drill, testing one thing at a time, and see where that points before spending another Euro on ANY repair or replacement.

As I always say --- ten grams of diagnosis is worth a kilo of repair.

Iride01 

Noises are quite often hard to locate. Noises that sound like they come from the BB usually aren't from the BB. Until you can pinpoint something going bad and actually interfering with your cycling, just ignore the noise. You'll spend less money fixing it when it's actually shown itself to you than you will guessing and replacing stuff that wasn't the issue.

oldbobcat

You're bottom bracket might need work or replacement, but the fact that it continues when you stop pedaling points elsewhere. When you're not pedaling, the only parts of the bike that are moving are the wheels and the freehub, If the noise disappears while start pedaling, then the wheels are OK.That leaves the freehub, also called the cassette body, which is the ratcheting part of the hub that allows you to coast. Remove the wheel, rotate it as if coasting and as if pedaling, and confirm this.

In general, I don't advocate freehub overhauls for beginners. Even freehub replacement often requires a full hub overhaul, a matter I can't resolve without examining the hub. I recommend taking the wheel to a shop. But if you insist, there are videos on YouTube and plenty of subscribers to this forum who will try to walk you through it.