7 speed freewheel - internal nut loose - clicking?
 

My dad picked up a barely used 1997-ish Mongoose Crossway 450 on CL. I think he got it for $70, and by the looks of it was probably ridden by the original owner a few times and put away in a clean dry place. No wear anywhere. Original tires have no wear but a bit of dry rot.

But - when you pedal the bike, in any gear, there is sort of a click or gentle knock in the drive train somewhere. Almost like the kind you get when you put a new chain on and leave the connecting link too tight and it doesn't go around the cogs smoothly.

I'm ALMOST certain it's not a crank issue. When the chain is off and you spin the crank it's quiet and smooth. No wiggle. I'm also pretty sure it's not a chain or cog issue.

So tonight I took apart the freewheel. The cogs look almost new. I've never taken apart a freewheel, so I'm not familiar with exactly how tight things should be in there. But in taking it apart from the freewheel side, first there's a narrow 17mm nut, a wide bushing, a narrower bushing/washer, and then the last nut that is a cone type that snugs up against the ball bearings.

That last nut was loose - not snug against the bearings. Probably needed to be tightened by about 3/16 of an inch. Could that cause the click/knock? I packed a bit more grease in there and snugged it down gently but not overtight. Haven't put the cogs back on yet.

Sounds like you took the axle apart, not the freewheel. Is the clicking regular with each wheel rotation, or pedal rotation, or random ?
All the axle nuts should be tight, with the axle spinning smoothly, and with no loose wiggle.

Freewheel info: http://www.sheldonbrown.com/freewheels.html

Assuming you actually have a freewheel and not a cassette:
You can try oiling the freewheel a bit. With the wheel off the bike, hold the wheel horizontal on your lap. Slowly spin the freewheel cogs backwards, and dribble in a little motor oil, like 10w-30 or whatever you have between the rotating part and the stationary part. About a teaspoon should do it. I usually dribble it in until I hear the clicking sound change to a more dull sound, meaning the oil has worked into the pawls.

Each pedal rotation, all gears. I know that sounds like the crank/bb - but there's not even a hint of it when you spin the crank with the chain off.

Yes, took the axle out, and had taken the cogs off...but correct, did not take the freewheel off/apart.

Sound like maybe you have a cassette, if the cogs slid off, and the body remained on the the wheel.

Anyway, it could be the crank/bb that only happens under load. Or the pedals. Sometimes saddles, fork or bar/stem can cause creaking that sounds like it's coming from somewhere else. With each pedal rotation, all those different parts get stressed. Ride slowly, and try to really pay attention to when it happens. You can also stand next to the bike with the brakes on & step on each pedal separately. Or straddle the bike, feet on the ground, and lean on the handlebars left to right.

In other words, try to make the noise one part at a time. There are lots of nuts & bolts that could be the tiniest bit loose.

If it happens reliably with each pedal rotation it is unlikely to be the freewheel/freehub. You say you've ruled out the crank/bottom bracket. What about the pedals?

Still a suspect in my opinion.

Just ordered a bb tool to take it apart...do'nt have the one I need. If nothing else, I'll end up with another tool in the box...

I think the bike has a cassette and freehub (by 1997 it should have) and the lockring is loose or missing.

HillRider - I think it's a Shimano HyperGlide Freewheel. From SB's pages:

http://www.sheldonbrown.com/free-k7.html

If you look at the pictures under "Identification: Freewheel or Casette" it looks just like the second picture from the left. I realize now that there was no reason for me to remove the retaining ring that holds the cogs on. The retaining ring itself was tight, with no play in the cogs.

What seemed loose was the nut deep inside - one side of which is basically a bearing race.

Homebrew has a point regarding the crank. Just because it doesn't make the noise when there is no load on it doesn't really eliminate the possibility that the problem is there.

JDT - doesn't seem like the pedals.

Billyymc:

If you have a FW, then I might suggest the following:

Step 1. Try to get a Shimano FW removal tool. Insert into FW, clamp other end in a vice or get a long handled crescent wrench find a big honking socket w/ half-inch drive wrench. If this isn't in a vice, have someone hold the tire, and then unscrew (lefty-loosey, rightey-tightey), the FW and remove it.

Step 2: Check the axle. Remove the nuts on one side of the axle (or loosen them completely and push out the cone to the point where you can see the bearings inside. Count them. All there? Repeat on other side. Spin the axle also. Is it straight? Check the the cones for pitting as well. If all is okay, then squeeze some more heavy grease into the bearings, and tighten cones and nuts. Secure one side first (e.g. the drive side). Then hand adjust the other side, and then tighten cone/locknuts. Spin the axle again to check there is no play, but it spins smoothly and lightly.

Step 3: Check the freewheel for spin. Use fingers and hold the center and spin the outside cogs. If it binds, then you need to lubricate or adjust the FW bearings. Sometimes the grease sets and freezes after many years of non-use. Soaking in solvent, then drying, and then grease-injecting (I use a Phil Wood FW injector) works wonders on my FWs and makes them stealthy and quiet too.

If all checks out, re-attach FW to hub, and re-install the wheel. I'd check the tire/rim/brake for clearance once installed just to make sure you don't have a wheel out of true or a tire that has a failed sidewall, or defect that is thumping the brake or the ground each rotation. And loose spoke can do that too.

That should clear the rear-wheel and FW as the culprit. The fault is likely to be elsewhere if things check out.