Friday, August 12, 2011

GIANT "Attraction" Re-Assembling the Bottom Bracket and the Three Piece Crank

Hello and Welcome. The heat-wave has finally passed and things are now returning to normal. Unfortunately I had to keep the outside work to a minimum while it was hot. So this week I have been busy getting the property cleaned-up. I did manage to get some shop/garage time in this week as well.
Above: The parts are de greased and ready for re-greasing and assembly. Pictured are the bracket, the drive side bearing cartridge (by itself) and the left side cup and bearing cartridge together. Also shown are the lock-ring and the crank-arm retainer nuts. I used the White-Lightning "Clean-Streak" to clean these up. I used my home made parts cleaning station. Notice: The drive-side of the bracket is longer than the left side. Sometimes the difference is not this noticeable. Might be best to mark the drive side end of the bracket.
Above: My home-made small parts cleaning station. Basically a cheap pot and strainer. I place dirty paper towels in the bottom of the pot, that speeds up the evaporation or drying process of the cleaner. It will evaporate by it self, but it does smell bad. This way I can dump the mess into a trash-can right away and be rid of the stink. There is never a shortage of dirty paper towels around here.
Above: The first thing I like to do is smear some grease on the drive-side cup which is still in-place.
Above: Now I lightly grease the bracket itself including the middle part to protect it from corrosion. After I grease the bearings I slide the drive-side bearing onto the drive side end of the bracket so that the exposed bearings surface are facing the cup (or out-wards). After I insert the bracket I turn it a few times to make sure the drive-side bearings are rotating smoothly inside the drive-side cup. Now that I know everything is feeling smooth I pack the left side bearing cartridge with grease and slide it onto the bracket with the exposed bearing surface facing out. (as seen above)
Above: Now I grease the inside of the left-side bearing cup. I slip the cup into place and thread it into place turning it clock-wise. But before I do that I have something else I want to do.
Above: Before I screw or thread the cup into place I wrap it once (counter-clock-wise) with Teflon Tape. If it were loose I could wrap it two or three times
without a problem. And I would also cover the entire threaded surface if I was not not convinced the threads were tight enough. But in this case it is being done to improve the seal and prevent possible creaking. The reason I wrap the tape counter clock-wise is so that as I thread the cup in (clock-wise) the tape will not bind up.
Above: Just like a head-set I tighten the cup until I feel the bearings grind a little, then back it off a hair. Also just like a head-set I don`t want to feel any grind or play. Note: It may never feel quite as smooth as the head-set, these are larger bearings. Once I am satisfied that is is not too tight or too loose, it is time to thread the lock-ring into place. Notice: I hold the threaded cup in position with a wrench while tightening the lock-ring. This will prevent me from accidentally over tightening the bearing cup.
Above: Here I have wiped-off the excess grease and I am now ready to install the left side crank-arm. Look closely and you will see some of the Teflon has made it`s way to the outer edge of the threads.
Above: I have slid the left side crank-arm into place. It will not slide on all the way. It`s ok, that is what the retainer nut is for. I normally start the retainer nut by hand to ensure it is not cross-threaded.
Above: Pretend my left hand is on the crank arm (it is actually holding the camera) this helps me get more leverage while tightening the retainer nut. Quick-Tip: Do not use an extension on the ratchet and do not use a deep or long socket. Keeping the set-up short will make it easier to keep the socket on the nut when tightening. After this, just screw the center dust cap into place and you are finished. (on this side anyway)
You might want to turn the bike around on the rack now. The chain-ring or crank side goes on the same way. Only one problem, this crank is a mess. I`ll have to take it apart for a good cleaning.
Above: The chain-rings cleaned-up easily using bio de greaser (the green stuff). I noticed a slight dent or bend in the bash-guard. No worries the chain-ring guard is thin and should be easy to straighten out.
Above: The chain-ring re-assembled and mounted, look at that baby spin! That went real well, or so it seemed. Once I got a chain on it, I found that not only was the bash-guard bent. The whole unit was bent. It kept throwing the chain right off the big chain-ring. Oh brother! What happened was this. The original chain was rusted badly. So I cut it off and tossed it and never spun the crank to see if it was straight. "My Bag" Well Thank God I never throw any good part away. I had another generic crank "same size" ready to go.
The replacement 3 piece crank works fine. It could use a little touch up on the flat satin black paint. I want to dig around first and see if I have a nicer 3 piece crank stashed around here somewhere. If not, then maybe I will re-paint it.
Above: This is me using the brass wheel-brush attachment on the rechargeable drill to clean-up the seat-post. I`m going to do a post in the next day or two about the brass wheel brush and how wonderful it works. After which I will post the finished project. Yes it is finished. And I think you are going to like it.
But right now it is late and I`m dog tired. So till next time RIDE SAFE and Remember to always RESCUE, RESTORE & RECYCLE !
Cheers,Hugh

8 comments:

  1. That's a clever idea using teflon tape on the bearing cup. It'll make it so much easier for the new owner to remove. I've just been using a tiny dab of grease. Next time, I'm going to use the tape. Thanks for that tip!

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  2. Hey Bill,
    Your very welcome. I first heard about using Teflon tape as a cure for a "creaky crank". But
    my thinking now is, why now just use it all the time? Especially on the "entry level" road bikes that have lesser quality threading on the bottom bracket shells. Three cheers for whoever though of this one!

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  3. Timely Post Hugh I am just about to tackle the BB on a 70's Raleigh Grand Prix project. Rather than go with the original cottered crank I am "upgrading" to a used cotterless alloy crank & bb. In part because I am not enamored of cottered cranks and in part because I destroyed the drive-side crank removing the $%^& stubborn pin! Oh Well. Let me know if you are ever short a non drive cottered crank arm for a Raleigh ;-)

    The teflon idea on the BB is a one I hadn't seen before so I will echo Big Oak and say thanks for the tip!

    Ryan

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  4. Hi Hugh, thanks for posting this, it helped me figure out that I had made the bonehead move of putting my bearing cages in backwards. I know, I know, I've done it the right way before, but this time I just did it wrong and of course couldn't get them to adjust right...then I read this, and thought, uh, OK, I put the cage wrong way in. Now headset and BB are much smoother. :)

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  5. Hey Ryan,
    I think anyone who tells you that cotter-pin cranks are "No Problem" has never ran across a tough one. I have gotten fairly proficient at removing them and usually they are not a problem. But every once in a while you run across one.... well you know the rest. lol
    I should do a new post about how I remove those stubborn b%$#&@*$. I have refined my technique somewhat since I last posted about it. (You may have to remind me though)
    Yeah the Teflon trick is pretty cool. I wish I could say it was my idea, but it was not.

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  6. Hey John,
    I think everyone is entitled to doing that once.
    (at least) One time I caught my self putting the left side crank-arm on the "drive side" of the bottom bracket. Apparently I had forgotten that I had turned the frame around on the work-stand. Sometimes you just have to laugh at yourself and move-on :)

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  7. Glad I found your blog, you have given me a lot of good info. I too was having troubles with the direction of the cages in hubs and bearings. So when I came across my current bike, which I rescued from an apartment dumpster, I was pleasantly surprised to find the wheel bearings were uncaged. After servicing the hubs I made use of an old parts bike and uncaged the BB as well. I dont recall how many ball bearings I had to add to fill the void but I'm pleased with the results. Teflon tape will be added at next overhaul.
    By the way, the bike is a 76 Powerking and I havent been able to find much on the web about it. Seems low end but well made Korean.

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  8. Thanks John,
    It is good to hear you found some useful information on the blog. I know the bottom-bracket bearings can be confusing to someone who is not familiar with them. I prefer caged bearings on the head-set myself. Seems like when I open up an older headset that has not been greased "in like forever", Some of the bearings always end up on the floor. But for hubs and bottom brackets I would think that free bearings would be superior.
    Power-King, that is a first for me! Maybe you can post a pic of it on the face book page. You can link to the F.B. page from the link section in the right column. I would sure like to get a look at it.
    Also, Yes the Teflon tape on the cup-threads on a bottom bracket is a good idea. I have made it part of my routine when over-hauling a bottom-bracket. It is especially useful on the less expensive bikes which tend to have lesser quality threads.
    Good Luck with the rest of your project. Cheers

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