BB axle races pitted, sand or not?
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BB axle races pitted, sand or not?
Doing a BB service on a square taper BB. Cup races look good, but the axel is rough on both ends. Should I lightly sand the pitting with emery paper or leave it? Should I replace the ball bearings regardless? I didn't remove the fixed cup, but may later as I may not be totally happy until I replace with a sealed unit. Just wondering if a light sand will help or if it will just make the axel more out of spec.
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Doing a BB service on a square taper BB. Cup races look good, but the axel is rough on both ends. Should I lightly sand the pitting with emery paper or leave it? Should I replace the ball bearings regardless? I didn't remove the fixed cup, but may later as I may not be totally happy until I replace with a sealed unit. Just wondering if a light sand will help or if it will just make the axel more out of spec.
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Yes, I realize that. What I am asking is, is there any benefit to doing a light sand? I will eventually replace cup and cone with a sealed unit, but I am going to assemble now until I get the parts and tools necessary to get the fixed cup off. I just wondered if I could do it any good with a light sand. I know what it would take to completely remove any scaring, and it would be too much IMHO.
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If you need to ride it while waiting on tools/parts, just throw it back together.
Where I am tools/parts takes 2-3 days. We don’t know where you are, YMMV.
Barry
Where I am tools/parts takes 2-3 days. We don’t know where you are, YMMV.
Barry
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Well Barry, I'll buy the park fixed cup tool, but I have to learn what to order for the sealed unit. Nearest bike shop is an hour drive one way so I can't just run by and ask them. The axel says 68=W=116. If you can point out the unit, I need perhaps I can get everything together in about a week. If not then I need to post and learn I suppose.
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You really only need to worry about pitting when the pits are in that very thin shiny line that goes around the race. That's where the ball bearings touch the race. And usually that is when it's time to toss the part for a new one. Change your lube more often if you are pitting. Don't confuse pitting with just minor etching that discolors the race in a blotchy way, but is probably a sign that pitting is about to happen if the lube isn't cleaned out and changed.
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Well Barry, I'll buy the park fixed cup tool, but I have to learn what to order for the sealed unit. Nearest bike shop is an hour drive one way so I can't just run by and ask them. The axel says 68=W=116. If you can point out the unit, I need perhaps I can get everything together in about a week. If not then I need to post and learn I suppose.
Posting the bike Manufacturer, Model and year will help someone identify it.
Barry
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You really only need to worry about pitting when the pits are in that very thin shiny line that goes around the race. That's where the ball bearings touch the race. And usually that is when it's time to toss the part for a new one. Change your lube more often if you are pitting. Don't confuse pitting with just minor etching that discolors the race in a blotchy way, but is probably a sign that pitting is about to happen if the lube isn't cleaned out and changed.
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I didn't know I needed a photo to ask the question. I know the races look rough on the axel. I'm not on my phone. I do have one. It stays beside my bed most of its life. I did take a picture of the axel for myself, but I would have to get my phone, log on this forum, and see if I could transfer my picture to this forum. I used to post internet pictures back when we loaded everything from photobucket. That's how anti tech I am. I don't like that a phone always with you is taking all your attention. My wife keeps one in her face all day and I hate it. It's like being plugged into the Matrix from the movies. A smart phone sucks all your life and feeds you a false reality. So, yea, I could figure out how to post a picture, but there's no concerted effort on my part to avoid it, I just didn't think it was necessary to go through the effort.
#14
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Pitting (otherwise known as “galling”) is not repairable. You can clean, re-grease, and keep riding, but your bottom bracket won’t be as smooth as it should be. You can’t really sand off the galling, you would just make things worse. Bottom bracket axles are usually heat treated, case hardened, or hard chrome plated, in either case, sanding removes the hardened surface of the steel. Square taper bottom brackets aren’t especially expensive, and not that hard to install.
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First step is to determine if the cups are pitted. If not, you could find a donor BB or BB spindle and replace the bearings and ride it for years without a care.
While cartridge BB are an easy fix, cup BB’s have endured for decades. A co-op or even eBay might be worth the effort.
The sanding might be moot, as you are not precision grinding it. If you use a lathe it might be better than trying something by hand, but I’d just put it back together and find a replacement.
John
While cartridge BB are an easy fix, cup BB’s have endured for decades. A co-op or even eBay might be worth the effort.
The sanding might be moot, as you are not precision grinding it. If you use a lathe it might be better than trying something by hand, but I’d just put it back together and find a replacement.
John
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I didn't know I needed a photo to ask the question. I know the races look rough on the axel. I'm not on my phone. I do have one. It stays beside my bed most of its life. I did take a picture of the axel for myself, but I would have to get my phone, log on this forum, and see if I could transfer my picture to this forum. I used to post internet pictures back when we loaded everything from photobucket. That's how anti tech I am. I don't like that a phone always with you is taking all your attention. My wife keeps one in her face all day and I hate it. It's like being plugged into the Matrix from the movies. A smart phone sucks all your life and feeds you a false reality. So, yea, I could figure out how to post a picture, but there's no concerted effort on my part to avoid it, I just didn't think it was necessary to go through the effort.
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#17
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OP: The pitting you have described is not "galling" as some have mentioned, but "spalling". If you want to get the bike back together right away, you may be able to use it. Usually, spalling happens on part of the rounded portion, but not most of it, and that part will be when that part is facing DOWN, when you are applying pedal force on that side. To use axle for now, clean it well, do not sand, and then mark on the end of the axle with red nail polish or any paint or marker, the orientation of the spalled portion. Grease and reassemble bottom bracket, preferably with new bearing balls. When you put the crank arm back on, orient the spalled area to be facing UP when the crankarm is in the forward-most position, as that is when the axle experiences its greatest load on that side. If you have spalling on both ends of the axle, that will also reverse the spalled portion on the other side. Adjust the bearing tightness before putting the crank arms back on, so you can spin the axle with your fingers; You want no slack, and a bit of preload on the bearings; Tighten bearing cup until spinning the axle feels "notchy", then back off ever so slightly until that goes away; When you spin the axle, you should feel the engagement of all the balls, not quite as easy as with no preload, but not notchy. Replace with a bottom bracket cartridge when you are able.
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Ball bearings are self tending. The rolling balls circulate grease, crush or push to the side dirt, and maintain the ball track the same way trains keep rails polished and rust free.
Other than periodic cleaning and refreshing the lube they neither need nor want your help.
Other than periodic cleaning and refreshing the lube they neither need nor want your help.
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Ball bearings are self tending. The rolling balls circulate grease, crush or push to the side dirt, and maintain the ball track the same way trains keep rails polished and rust free.
Other than periodic cleaning and refreshing the lube they neither need nor want your help.
Other than periodic cleaning and refreshing the lube they neither need nor want your help.
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#20
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Ball bearings are self tending. The rolling balls circulate grease, crush or push to the side dirt, and maintain the ball track the same way trains keep rails polished and rust free.
Other than periodic cleaning and refreshing the lube they neither need nor want your help.
Other than periodic cleaning and refreshing the lube they neither need nor want your help.