7700 BB Saga/Rant

[oldpotatoe]

Originally Posted by 11.4

I've had to work with a horde of Octalink bottom brackets and found that the source of the corrosion (and from an electrogalvanic standpoint there has to be one) is almost always the bolt securing the bottom bracket cable guide. Most people use a bolt that rusts -- even if they choose stainless, it isn't necessarily good stainless (your Ace Hardware stainless bolts aren't the same stainless that you'd get in a high-quality sheave on a racing sailboat). That bolt rusts and the oxide flows to one point on the edge of the alloy and starts eating there.

I found some high-quality nylon bolts and started using them in bottom brackets to secure the cable guide and guess what? ... bottom bracket corrosion stopped. I've also gobbed the inside of that stainless bolt up with anti seize and that's done a pretty good job of preventing it as well.

I agree with Spud about the needle bearings in 7700's. They come in a plastic clip and work fine at first, but as the clip wears, they fall out. You can retrieve them, stick them in with grease, and everything continues to work fine, but if you lose one, you're hosed. It was indeed a great bottom bracket, but it didn't have a long lifetime. On the track, where you can install it and simply not open it for several years, it's simply superb. I'd never ride one on the road.

Some track guys mention 'lash' with octalink, pushing against both sides of the aluminum notches of the crank.

[ultraman6970]

Mark you did great with the tool, your are really crafty dude.

I been successful using the tool vice technique, the tool - quick release - friend with a hammer technique and what I been using lately is a tool that is similar to the bolt and nuts technique/tool that is moving around, the problem is that it doesnt work with BB as the one you are talking about.

It is so simple, a lot of grease and teflon tape and the threads will be safe from rust forever.

I dot have to agree, since long time ago i was wondering why the cups dont use hexagonal notches, still can't understand how in the world did you cut the metal, that thing was just perfect. Bet you built your own 32 headset tool hehehe

[josephr]

thanks to oliver1850 for inspiring this rigging work to remove a Shimano Octolink BB --- since I didn't have a bolt/washer long enough, I got out the bearing press with a box wrench on the BB tool. Did an Old Patatoe no-no and whacked it with hammer --- broke loose with a few good hits.

[miksibis]

i feel so inadequate after reading this post!

the shop guys once made me leave the building before they broke out the cheater bar to remove an old bottom bracket from my landshark. no witnesses!

[pbarry]

Serious tenacity! Big props for the effort and ultimate victory.

[TBDSeattle]

Love the story, and love the photos even more.

We had a cheater bar in the corner of the shop where I was working while an undergrad. We wouldn't use it in front of customers either, as I recall. I was there a couple of years before I learned that I should be clamping the tool and turning the frame.

Oh, and once we cut out a seized aluminum bb from the bb with a dremel tool. It was careful work to cut just the bb cup and not the threads of the bb. I remember sweating a bunch while performing the cuts (had to do 3, so I could tap out the sections one at a time) but it worked perfectly. I don't see myself doing that job again!

[buldogge]

Nice work Mark…

I have had to stick TWO frames up on the mill so far to remove stuck BBs…both ITA threaded. My Chesini came to me, from France, with a free DA BB…jeez, thanks! My Reus had an older Athena BB…same issue…that one I rode for years until I went to swap UT cups in.

We milled out all the bearings/guts and pulled the spindles and then milled the cups close and chiseled out the remains…have to tread lightly as you get closer to the shell threading.

PITA

-Mark in St. Louis

[ultraman6970]

At least you have tools close to you, the problem is when you have nothing around...

[cderalow]

i replaced the splined square taper shimano on my hybrid recently.

i ended up using my pneumatic impact gun to break it loose.

damn drive side did not want to budge.

[Gummee]

Originally Posted by oldpotatoe

Upgraded many to the far superior 6500 BB...

Had one. Realized that it needed re-building and promptly paid the 50g penalty for the 'install it and forget it' Ultegra version

M

[texbike]

The most proper way to handle a 7700 BB is to be extremely careful when removing the BB from the shell, wipe it down gently with a rag once it's removed, and then pitch that cursed piece of crap as far as you possibly can into the nearest large body of water.

What was Shimano thinking on that design????

Texbike

[tumbler]

Originally Posted by 11.4

I found some high-quality nylon bolts and started using them in bottom brackets to secure the cable guide and guess what? ... bottom bracket corrosion stopped.

This sounds interesting. Where did you find the nylon bolts?

[Grant McLean]

Originally Posted by texbike

What was Shimano thinking on that design????

Pretty sure they were thinking mechanics would use the proper technique.

All you need to do is secure the tool to the splines with a nut that holds the
tool tight against the cup, and it can't slip because the BB axle
holds everything in place. I would recommend that for any tough to
remove cup. Slipping on the edges is the downfall...

I love both the XTR and 7700 octalink BB's. My 1997 mountainbike
is still going strong, have 3 in service on road bikes. They are easily
cleaned and serviced, which is I suppose the reason for the hate,
since people neglect them, and then rant about how they suck.

[Look585]

Originally Posted by Grant McLean

Pretty sure they were thinking mechanics would use the proper tool (TL-UN96).

That is not the tool needed for a 7700 Bottom Bracket. The 7700 fixed cup and the adjustable cup lockring have a 6 prong design. I believe there is a Shimano tool, but I cannot find the part number. The Park tool version (which is crap) is BBT-7. It should be used very carefully and only with a stack of washers and 15mm bolt threaded into the BB spindle so it doesn't slip and trash the cup/lockring notches.

They spin very well when properly maintained. For me, track use only.

[Grant McLean]

Originally Posted by Look585

That is not the tool needed for a 7700 Bottom Bracket. The 7700 fixed cup and the adjustable cup lockring have a 6 prong design. I believe there is a Shimano tool, but I cannot find the part number.

Agreed, i realized that after my initial post. With the proper technique
of securing the wrench (something I do on every cup and lockring)
it's really not any issue to remove them.

Of course, the other important factors with (any) aluminum cups are to
1) use a proper anti-seize compound on the threads.
2) turn it the correct direction when trying to remove it!

-g