Temjin.456

Ok so I received this dumpster snorkled Walmart bike last year. It's a Pacific Scorpio XS, with a front Suspension fork that needs rebuilt, and a wobbly Drive. It has the coolest shifters ever, I hate the thumb ones that radially operate, these I am told are shifter clickers. I'll let pictures and youtube show you what I mean. After putting around 23 miles on the bike this March before it decided to be cold again. I noticed that after 10 miles of riding I heard a grinding creaking noise, that only occurred under force.
I thought it was my rear hub because the noise happened when I applied weight to the frame and rolled the bike forward and backward. But this noise only happens after riding for a while, if it sits for a couple of hours the noise is gone. After telling my friend, he said it was the bottom bracket, because the noise only happened under force. he also grabbed the back tire and checked for lateral movement and said the rear hub should be replaced. He said if the hub or cranks moves laterally at all it should be replaced or checked. So I get to learn how to rebuild and service a hub. Long story short I was given a sealed Shimano BB-UN40 68, he said it might fit but would probably be too short. He also expressed concern on standard and non standard threads, and that I might have non standard threads.
Well after receiving the tools a Crank puller, and a BB tool. I was told go, turns out the tools are pretty self explanatory, the cranks came off, then I found what looks like cups but I can find nothing in the way of specialized tools to remove the cups. They look proprietary but what do I know. Youtube and the internet don't help, anything in the way of "Bottom Bracket Removal MTB". All I find are the sealed Shimano units, this does not look like a Shimano, but maybe it is. The pictures should be self explanatory.
A word of warning the pictures are large. Taken with my pops Iphone 4S. Let me know if the pictures are too large I can scale them down.

Pictures of the Bike:
https://img818.imageshack.us/img818/7963/img0052ng.jpg
https://img859.imageshack.us/img859/3646/img0053rb.jpg

Tools and Bottom Bracket:
https://img338.imageshack.us/img338/9062/img0051iw.jpg

My reason for fixing:
https://www.youtube.com/watch?v=E3h1qPDxq3w
https://www.youtube.com/watch?v=Nou_a42n390

My reason for assistance:
https://img526.imageshack.us/img526/4...g0046copyb.jpg
https://img31.imageshack.us/img31/2439/img0044copyb.jpg

JanMM

Yes! You have properly identified the cups. The fixed cup is on the drive side and is often difficult to remove - you must know/remember that it's threads are backwards - turn clockwise to loosen.
Some help from Park Tools - https://www.parktool.com/blog/repair-...racket-service

Looks like you already have the lockring on the non-drive side off. You may be able to remove the adjustable cup on the non-drive side by using a hammer to tap with a large screwdriver. The drive side cup can be removed with a tool like the larger one in the photo.

Some remove drive side cups (after removing the adjustable cup and axle) by securing the cup in a vice and then using the bike frame for leverage in turning the correct direction.

onespeedbiker

What you have is an older style loose ball bottom bracket. The outside part of both sides have races or polished surfaces for the loose ball bearings inside. You remove the bottom bracket by removing the cups separately on both sides. When you remove the cups you can replace it with a single sealed unit; the Shimano BB-UN40 you were given (if the spindle is long enough*). As mentioned the side with the exposed threads is called the adjustable cup which is held in place with the lockring you already removed. It will probably be fairly loose now, once you break it free of the accumulated grunge.The other side or drive side of the bottom bracket is called the fixed cup because it's screwed in all the way and doesn't adjust. To remove this cup you need a large crescent wrench that will fit the flats of the round top of the cup or use the tool shown above that has a large round cutout with opposing flat surfaces that will fit on the flat surfaces of the cup. As JanMM said In other words to remove the fixed cup you must turn it the same direction as if you were tightening it. Go to the Park tool site link to by JnMM. Below is a diagram to show what the inside of your bottom bracket looks like.


*If you look at the diagram above you will see the part of the bicycle where the bottom bracket (BB) goes called the "Shell"; these come in two different sizes (that you need to be concerned about), 68mm wide and 73mm wide. The sealed unit given to you is marked "68" (under the "BB-UN40" marking) for 68mm. Usually road bikes and some mountain bikes use 68mm BB while the balance of the mountain bikes use a 73mm BB. You will need to measure the width of your bicycle's shell to find out which one you need (measure the width of the shell without the BB). If you don't have a millimeter measuring device, 68mm = a little more than 2 5/8" and 73mm = about 2 7/8".

The bottom Bracket also has a spindle measurement. If you remove the plastic threaded installation ring (or cup) and look at the base of the spindle, you will see the size stamped into the spindle; probably 110mm or 113mm. to measure the stem you removed from your bike measure from end to end, not counting the threaded studs. 110mm= about 4 5/16" 113mm= about 7/16". Assuming you are going to eventually replace your old BB with a new one, you will also need to pick up a pair of crank bolts, as the newer spindles do not have threaded studs; they have threaded holes that need a bolt.




An educated guess is you will need a 78x113 to fit your bike; if so the sealed unit you have will not fit.

Temjin.456

Well thanks guys, I figured I would need some crazy tools. Now I know what type of BB it is (Wicked). Whats odd about all the grunge is, the Cranks, and the nuts holding the cranks to the BB, all came loose real easy like this bike had been taken apart before, or it wasn't torqued correctly, either way I feel real lucky. I read through ParkTool's page for bike maintenance, but did not see anything about my bike's BB, so I was confused as to what to do. I came here, and got the answer I was looking for. Now off to the LBS to see if I can get a used BB or price out a new one. Oh one other thing my neighbor has grease that he uses on bikes but its not specifically used for bikes, if I remember correctly it's used for automotive parts. It's grease that comes in a tub, its dark brown or black, you can buy it at Automotive stores pretty much anywhere. He uses it to grease bearings on the older style one piece cranks. Would that be alright to use as a stopgap until I can buy the right grease, or would it be okay to just use it.

Thanks again guys.
I'll let ya now how it goes when I get up tomorrow, and work on it.
I want to get this bike ready for warmer weather.
Maybe I wont have lower gear skipping after I replace the BB wont that be nice.

Bill Kapaun

A Park HCW-4 is the wrench for the fixed cup.

A Park HCW-11 is the wrench for the adjustable cup.



Use a bit of penetrating oil and you can probably screw it off with an adjustable wrench or??

I use use automotive wheel bearing grease or boat trailer wheel bearing grease.
IF it comes in a tub and is used for cars, it'll be fine.

Temjin.456

Wicked! Looks like I'll have to see if the LBS has one I can borrow, or buy. I dont think Ive got a crescent deep enough to fit it, will look though.

Thanks again.

Reynolds 

Any good grease would be fine.
The fixed cup can be pretty tight, beware of the wrench slipping. Sometimes you have to use a cheater bar.

onespeedbiker

Not sure about the grease question. The sealed bottom bracket is just that a sealed unit that does not let you access the bearings. You may want to put a little grease on the threads when you screw it in, but besides that there is not need for any grease (some people like to use Teflon tape on the fixed side but keep the plastic ring dry). One thing that has not been mentioned is you may be able to get away with just cleaning up your old bottom bracket and putting it back in. It's doubtful considering the age and quality, but back in the days before sealed bottom brackets, routine maintenance including removing, cleaning and re-greasing the bottom bracket (this is where you need the grease). Once you get the spindle, cups, bearings and races out, clean them up and shoot us a photo; even if there is some corrosion it may be good to use again. Good Luck!

And BTW, before you worry about some tool to remove the adjustable cup, just give it a few taps with a screw driver and a hammer. The adjustable cup is not really tightened down it is just used to slightly tension the bearings so they don't rattle around and many times will come loose just by unscrewing it by hand.

Temjin.456

Yeah nothing was really tight just the Drive side gave a little issue. I took the BB to the LBS, he took one look at it in its dirty state and said yeah it just needs cleaned and regreased. So that was 2 dollars hopefully well spent. The Races looked fantastic and smooth no gouges on it at all. I took pictures of it after I had just taken it out. But I did not think to take a picture with it cleaned up. I still sounds a little grindy but nowhere near as bad. So if this can last until I get my friends Giant, then just use this bike as a learning tool. I will be happy. I am concerned about my cranks specifically the non drive side. It looks as though someone hit the crank with a hammer and gouged out the square tapered hole a bit. I'll let the pictures do the talking. When I told the LBS mech that, he said it wouldn't tighten down correctly, he used a very specific word to describe the type of damage I was describing. I can't remember it though.

Grungy Bottom Bracket:
https://img4.imageshack.us/img4/1134/img0054wd.jpg
https://img404.imageshack.us/img404/2050/img0055xa.jpg

Rusty inside:
https://img851.imageshack.us/img851/8513/img0056psy.jpg
https://img717.imageshack.us/img717/157/img0057wtx.jpg

Funky Crank damage:
https://img851.imageshack.us/img851/9038/img0058mv.jpg
https://img850.imageshack.us/img850/9148/img0060wr.jpg

Thanks again guys.

Temjin.456

Well everything is back in, very little grind noise, prolly after the grease gets in real good to the bearings, the slight grind will stop. Going to take some tools with me and go ride the paved trail. See what 10 miles does and see if the creak/grind noise comes back. Hopefully it wont, I'll be glad if it doesn't do it at all. Another quick question, it can prolly be found in the Parktool's maintenance info. When should I take the BB back out and re-grease and check for wear. If it is, just tell me and I'll take a gander when I get near a PC again. Can only do so much on my phone.

Thanks again.

zukahn1 

If you have a big enough wrench you can often get the BB cups off if they are not to tight or stuck I would try this before getting special tools.

dabac

There's really no set interval. Some would happily ride until the need for service becomes self-indicating, others would service yearly. Some would service when the bike has gotten good and wet.

Temjin.456

Well it wasnt the bottom bracket. The noise came back only after about a mile in. I dont know what it is. When i get a camera that records decent sound. I'll post a vid.

Bill Kapaun

IF you tightened the adjustable cup even slightly too tight, the bearings will feel gritty. It's a pretty fine line between too tight, just right and too loose.
Be generous with the grease. There's no reason to expect it to "work in". The problem is that it "works out".

You can remove the chain off the rings and spin/turn the crank to isolate it for noise, grittiness etc.

You did use new balls didn't you? For $.05 each, don't mess with the old ones.

Temjin.456

Uh no the LBS just cleaned and re-greased the BB. He may have put in new balls but I was too busy looking at his Trek 950 he wanted 125$ for. The grind noise was there after the cleaning and re-greasing. But is very faint, and barely noticeable. The gritty feeling I felt, is nice to know that I can loosen the adjustable cup, to make it go away. Tomorrow I will take the BB back out and put more grease on it, just to be on the safe side. The LBS had already greased it after cleaning it and placed it in a zip-loc bag to keep dirt off the unit itself.

Thanks Bill.

bobotech

If you grab the crank arms and try to rock them firmly back and forth to and from the frame, do you feel *any* play at all? if so, then the bottom bracket wasn't tightened down all the way.

onespeedbiker

What Bill was referring to is how tight the adjustable cup is. When you thread it on it should be tight enough so that the spindle doesn't rock but not so tight that the spindle binds or feels gritty. This is a touch thing that usually takes a few tries. When you first tension the bearings the spindle may feel free to spin, but when you tighten the lock ring it sometimes over tightens the cup. You then need to loosen the lock ring and try again. Even if you manage to hold the cup in place when tightening the lockring, the mere force of tightening down the lockring will change the tension; it usually takes me a few tries before I get the tension (or preload) where I want it. See if you can let off some of the cup tension to quiet down the bearings.

UnsafeAlpine

What part of Michigan are you in?

Temjin.456

In reply to "bobotech" I made sure to follow the instructions I found on the Maintenance guide, there is no crank side to side movement what so ever. I made sure to lean the bike against something and push and pull with some force, but did not wrank on it.

In reply to "onespeed" that tidbit of information is nice to know, I haven't been outside today to adjust the cup.

In reply to "UsafeAlpine" I am in Mecosta County.


Thanks again guys for all the info!

Reynolds 

You must assure the adjustable cup doesn't move while tightening the lockring. If you can't get an exact, free-but-no-play adjustment, it's better to err on the loose side.

UnsafeAlpine

Ah, cool. My wife and I were up in Manton last weekend.

I have no helpful info for you, though. Good luck with your problem.

Temjin.456

I did the adjustment yesterday and everything is fine, no gritty feeling, and no grinding noise after a re-greasing and new ball bearings. Everything spins nice and easy. All in all it wasn't as hard as I thought it was going to be. Now on to diagnosing a very annoying noise, but that is for another thread.

Thank you again guys, I'll be sure to point others in your direction. You have helped me immensely.

JanMM

Now that you (and the LBS) have an adjustable BB overhaul under your belt, you should be able to handle most other bike tasks.
Ride on.