Hope XC bearings - galled the shell. Solutions?
Blundered. What was a great set of Hope XC hubs (early 2000s generation) had a rear bearing that wasn't smooth anymore. Researched a bit on line, and happened to have a new set of ABEC5 Enduros here, so I went for it:
Removed the freehub, and with more effort than I would think necessary, I was able to knock the axle and bearings out. Double & triple checked the new bearings, and they match what came out.
Went to press in the inner bearing, and at ~1/2 way mark, the bearing seating went from straight to cockeyed. I backed out the press and removed the bearing, and it seems I've galled the inner hub where the bearing seats.
Other than this, the hub is in great shape with low miles. What can I do at this point to get a bearing to seat properly? Anyone run into this before? Suggestions?
Carefuly remove any raised up burr in the hub body. Lightly lube with grease. Stick cartrige bearing in freezer for a while. Heat up hub body with hair dryer....not so much as to damage anything.....Grab that bearing and work fast!!!
It might help to use a socket just smaller than the hub bore but large enough to push on the bearing outer ring and tap it into place. That way you might be able to see it better and avoid getting crooked.
Just make sure your not pounding the bearing in by its seal or inner race.
Thanks for the advice. I spent most of this morning working down the high spot, and tried to install again. And again, the bearing went crooked on me. Thankfully, my calipers just arrived in the mail today, so I think I will be better able to measure any high spots now.
I'm really surprised at how tight it was, starting with removing the old one. The tolerances seem non-existent, or perhaps negative even. Had I not knocked out the old one myself, I'd at this point have doubts that it could fit. My Hadleys have been far easier to work on.
I like these hubs when they work, so my fingers are crossed...
Originally Posted by Entrenador
All press fit are an interference fit. Meaning that tolerances are negative. The ID of the shell is smaller or at the very least equal to the OD of the bearing and you want it to be like that.
Headset cups, frame pivot bearings and some BB bearings are press (interference) fit.
Maybe you got a shell with the minimum ID allowable and the largest OD bearing allowable. That makes the interference even tighter.
At any rate, thanks for the heads up. My old Bulb rear hub is doing the same. Tight bearings (not notchy or anything, just too tight) and they don't want to come out easily. It means that drive new ones in will be a challenge.
E; the other thing you can do is wrap the bearings in a ziplock bag and throw them in the freezer over night. This will "shrink" the bearings slightly maybe enough to press them in easier. I too would agree to warm up the hub with a hair drier or a heat gun(careful with that one).
Man, that was a b!tch.
Calipers showed 27.8mm ID on the hub shell, and the bearing was 28.1. I still had some slight galling after the third attempted install, so I used some 200 grit emory cloth and went about 10 passes all the way around. Then I hit the ID with a tiny wire brush on my rotary tool, which brought back the smooth finish. Meanwhile, the bearing was in the freezer. Cleaned the area thoroughly, added a bit of grease, and gave it slow, careful & light try again: tighten the press, wiggle, repeat. Finally got it in on the 4th try (yeah, yeah... that's what she said!).
Originally Posted by Warp
On the non-drive side, the same issue came up -- the outer bearing wouldn't seat all the way. No galling this time because the axle shaft kept the bearing from seating cockeyed. The difference here was a hair over .2mm, so I hit it with just 5 passes on the emory cloth, rotary polished, greased, and pressed it in. The bearings felt notchy after putting it all back together, but I tapped the axle from different angles on both sides, and now it's smoother than it was originally when new.
With the metal being so soft, I was concerned that I was only making things works. I was perhaps on my last attempt to save this wheel set from being disassembled, so I'm happy it finally worked out - climbed out of yet another "oh sh!t, what have I done?" ditch.
Thanks again for all the help y'all.
Glad it all worked out. That's what friends do when one is down in the "oh sh!t" ditch; we jump in with them ;-))
Happy to see it went in.
Wow....! .3mm is like .012" thats crazy. I thought an the bore in that kind of fit should be something like .0005" to .001" smaller.
Still it is done and should last you a while.
Don't quote me, but I think 1 1/8" headsets have an interference of 0.1mm or 0.004". The diameters are similar. 34mm for the headset cups and 27mm for the hub bearings (or just around that, you get the idea).
Originally Posted by fermenter
Nicolai goes as far as specc'ing their headtube to headset cups with 0.3mm interference on purpose for a tighter fit.
No reference point
Strangely I've been a bike wrenching hobbyist on my own since 2003, and only two days ago used a set of calipers for the first time. Until now, I guess I've been lucky that everything has just fit well enough not to bother measuring.
Originally Posted by Warp
With that said, I don't really have a frame of reference to know how much interference is too much. In my oversimplified brain, a good fit would be equal ID & OD, with any interference being just about impossible to work with. Probably played with one of these too much as a kid:
I'll keep your .1mm as ~normal in my noggin for future reference.
Wow. I just got some new ABEC3 bearings off fleabay for my Pro2SS hub. I'm a little afraid to pop it apart, now.
I did my Hope XC hubs a couple years ago, and that wasn't bad. I just did my Real hubs, and they were pretty easy.
So, you use a press for this? Nice! I just used a socket, extension, hammer and wood block on mine.
My guess is you measured under size. Dial calipers are not the right tool for precise ID measurement.
Originally Posted by Entrenador
I bought the bearing press kit for the Blur frame from SC a while back, it came with a long threaded bolt (3/8" I think) and a bunch of various spacers and such. Between the three different factory press tools I own (can't recall what the others are for at the moment, lol), I've been able to rig something up for just about every bike application so far.
Originally Posted by pimpbot
I sandwiched the proper 13/16" socket on the bearing side of the press, and used an old loose BB bearing cup on the other end, with some requisite washers between it and the nut at the end. You're welcome to borrow it if yours uses 6001rs bearings. Worked fine for the inner bearing - so well you might think that's what it was sold for. Had to tap the non-DS side bearing in with a socket and a soft mallet.
I expect your ProII hubs will be easier than my oldie but goodies.