Wobbly wheel after tightening cups and cones
 

I have an odd situation that people here might appreciate. BLUF:I have to improve a crappy old Trek Mountain Sport 800 from 1995. I know it makes zero sense and I could buy a better bike for half the price of parts, but just accept this is the way it has to be.

Right now I'm facing a problem where I'm trying to overhaul the real axle. It was a 6 speed freewheel and I'm moving to 7. I got new bearings of the right size, and tried to get a new axle but it seems the wrong size. When I put the old axle in and tighten the cups and cones real tight, too tight, and then put it into the frame and tighten the nuts (it's not quick release) the wheel immediately gets wobbly and loose. Once I remove it I find it loose, not tight like it was seconds before. I swear I'm tightening these as well as I know how, and locking them. I don't know why they're loosening with merely tightening the wheel on the frame, or rolling around the house for a few feet. What am I missing about this process?

You're tightening each cone against its locknut, right?

Yep. Tightening the cones appropriately, then using the cone wrench to hold the cone in place as I tighten the lock nut. Testing that it's still tight after that.

For what it's worth the bike seemed to be missing a dust cap on the drive side. I've tried using it with and without that using the extra one I bought. That other one is a little too small. But it seems I need it to not require more spacers to allow the freewheel to spin without hitting the frame.

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Take it to someone that has the Correct Parts, The Right Tools, and Experience, Before You Ruin the Hub.

I'd first suspect either too many balls, wrong size balls, or wrong cone.

Since you're missing a dust cap anyway, find a photo of what it should look like and compare. You can use a Q-tip to remove excess grease so you get a clean view.

Has the OP overhauled and adjusted a hub before? Has he watched a YouTube video of the process? Read Sheldon Brown?

6 and 7 speed use the same axle. Why did you replace the axle at all?

Sorry, I should have explained myself better. I am using the same axle. I did buy a new one in case the cones or other components were worn, and because the dust cap seemed to be missing from the drive side of the original, and because a new one was like $9. But I'm mostly sticking with the original axle.

Thanks, I'm sure it is one of those problems, I'm just not sure which. I don't doubt I could be doing something wrong, hence my question. But that is the process I'm following. But then somehow when I put it on the bike and tighten the nuts and roll it a few feet it suddenly has play in it. I'm just not sure why.

I haven't overhauled a freewheel hub before. I have adjusted hubs before though. I have watched youtube videos. I've tried reading the relevant parts on Sheldon Brown but that website is so large, it's hard figuring out which parts apply directly to my problem.

Did you have a specific recommendation as to what might be happening? It seems that the last step of tightening the axle onto the frame and rotating the wheel is what's causing the problem, for some reason.

Thanks. I did notice when I went to overhaul the hub that the old ball bearings were caged but the cage was falling apart. I did try to measure on the other side, with an intact cage, the size and get the same size. I also used calipers to measure the ball size and get the same size ball bearings. But perhaps I can use the old ball bearings without the cage and add one more, if that could potentially be the issue.

This bike is just not worth the cost of that. It'd probably be cheaper to get a new wheel, to be honest, before that.

Have you ever seen this issue, or do you have a specific idea as to why it seems that tightening it on the frame and/or rolling it a bit is loosening things? It does spin freely and seems okay, it's just when I grab the frame and move the wheel there is play when there wasn't right before putting it on the frame.

or possibly you left one ball out ? an omitted ball bearing will sometimes do this

/markp

Are you using caged bearings or loose bearings? I had this same problem with a Sachs 3 speed IG cassette hub, also with a solid axle. I speculate that I was putting the caged bearings in backwards but don't really know. When I dry fit everything it seemed correct but obviously something wasn't going well. Regardless, new, caged bearings of the appropriate size are not readily available. I finally gave up with cages after 3 or 4 attempts and reassembled everything with loose bearings and all is seemingly good so far (100 miles or so).

I don't believe so. I replaced it with a caged ball bearing, so I don't think I could have left one out. It was the same diameter as the other one, so I think it would have the right number of balls, by virtue of it being caged.

Oh, that's fascinating! Thank you! That could be the issue. I am using caged bearings. I did try to dry fit it, as you say, and see which side the cage should go on to fit appropriately and not rub. But perhaps I got it wrong. Or the dust cap being missing and replaced with a different one means it's not fitting right.

This has happened to me. As I'm threading the second cone onto the axle (after seating the first one and making sure it spins), I will accidentally roll the ball bearings out of their race so they "bunch up." When I think I'm done the axle feels snug, but after spinning the wheel it will bind or feel loose and not spin true.

Here's what I do. Unthread that cone enough to push the balls back into the cup correctly. Then, as I thread the cone back down, rotate the axle from below instead of rotating the cone. Eliminating rotation between the cone and cup will prevent the balls from crawling out of place. When you're assured the balls are in place, do your fine adjustment as usual.