So I found a nice vintage steel Bianchi in the trash that had been really poorly assembled by the so called "mechanic" or a previous owner and decided it needed to be rescued and put back on the road.

The frame has no rust and looks like it was stored in a warm garage all year round, but there were a couple issues. The first of which was the aluminum seat post (which was installed without grease into the steel frame decades ago) which I somehow freed using a 6 foot steel pipe, vice grips, lemon juice, and lots of determination.

The second issue was the old school bottom bracket (also installed with no grease) with a right side shell that actually cracked in half on the last owner (probably why this bike was tossed). I knew the threads were going to be in rough shape as pieces of the BB cup were grinding against the edge of the BB shell for only god knows how long. The shell was also never faced, which could have been why the BB cup cracked in the first place.

I used a Dremel to thin the wall of the old broken BB cup, cracked it, and removed it (as there was nothing for a wrench or tool to grab on to) which worked beautifully. When I finally got a look at the thread damage, it wasn't as bad as I thought, but still pretty bad.

The first few threads are the only damaged ones. They're cross-threaded in a couple spots and there is some slight damage to the edges of the BB shell, so I figured I have 3 options.

1. Get my LBS to try and chase the existing threads & face BB shell

2. Ream & rethread to italian and face BB shell

3. Do nothing to the threads, face the shell, and get a threadless BB (like the one from Sunlite)

What do you guys think I should do?

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From your description it sounds like all that is required is option #1.

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Chase and face to the existing thread. Make sure the BB you intend to use engages enough clean threads to make you comfortable using it.

Thanks! I wanted to post a few pics but I'm a newbie so it won't let me yet.

I'm going to one of the most reputable shops in the city this afternoon so they can check it out, but it will be nice to go in there knowing there is some hope for the existing threads (it's ISO threaded currently).

Will be nice to get this beauty back up and running!

I just went thorough this and have saved almost all of these I have ever encountered over the years. I always start with a through cleaning, then I use a right angle pick and start from the inside and work out thread by thread using pressure to clean and straighten the threads as best I can, next I take a spare correct BB cup and cut rethreading slots in it with a small Dremell cutoff wheel to make a chaser. Then carefully by hand if possible run the chaser in using tools and force only as necessary. Success rate is near 100% over the years as a fomoco and ASE Sr Master technician, at the dragstrip, in the driveway and on the side of the road, requires patience, the right tools, steady hand and now days close up glasses.

Agreed with a good thorough and proper chase of the threads and if the shell needs, a facing, done accurately. If you can perform the chase with the needed precision that Merziac detailed, then the majority of the work is done.

But since you decided go to a shop be sure they have the proper tools for the work. With the proliferation of press fit bottom brackets some mechanics haven't performed either operation. Find an LBS with an old school mechanic that has the skills and that owns the correct tooks. From your description, its a good, well experienced shop. I have any frame I acquire faced and chased at our LBS, by a friend that owns several Campagnolo complete tool sets, and the knowledge to properly use them. This saves time, money and anxiety down the road.

Good on you for saving the bike, you get extra C&V karma points up in bicycle heaven. Spend them wisely.

Bill

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...one other thing that can help in this situation (where there is some thread damage, but still enough good thread remaining to simply rechase and install something new), is to use a sealed cartridge, rather than returning to an old school BB unit. If you picture it in your mind, you can see that a sealed unit will distribute the forces of the crank and spindle rotation differently, and a lot of the force gets focused through the internal races of the sealed unit over the entirety of the shell threading via whatever plastic caps you use to install it.

Just a thought in case you are interested.

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...oh yeah, if you're in Sacramento, CA, you can do this at the bike co-op.

Oh for sure - one of the first things I do when I get an old abandoned frame is get that big nasty heavy old school bb out of there and replace it with a new style sealed bb.

Why spend an afternoon fiddling with loose bearings and cups and a clunkly spindle when you can have machines at a factory seal it all up perfectly for you ahead of time

I've had mixed experiences with shops in the past, so I'll be going to this one for the first time after lots of research.

I live in Toronto, and more than 50% of the bikes on the street being ridden were made well before the 90s, so luckily there are lots of mechanics here who have experience working with older frames...the trick is finding the best ahah.

I also support chase the existing threads. If an Italian re-thread gets screwed up, you're in a deep hole. Unless you live in a big city or are just plain lucky, you might have difficulty finding a shop with Italian taps anyway. Nearest one to me is about an hour away.

Just in case you run into problems after the chasing, here's a solution I used not too long ago. A year or two ago I rehabilitated my '96 C40 which had worn (Italian) BB threads; the drive side would not cinch down, it would slip and loosen up. The mechanic at the DBS (distant bike shop with the Italian taps) recommended not chasing as it would eat up what little thread was left. He recommended a threadless BB, but I couldn't find one in Italian width. I ended up using a Phil Wood. The two adjustable cups work nicely to tighten against each other through the cartridge. I used some blue Loctite and all is well about 1000 miles later. Good luck! Post pics!

This makes me wish you were the one doing the work on my BB shell!

Sounds like it works beautifully...I would never trust myself to do it nearly as well though. I have the tools and know-how to do pretty much everything on a bike except for cutting threads (just the thought gives me anxiety ahah)

I will definitely have to remember this! If not for this Bianchi, for future bikes I work on. Which specific model of Phil Wood BB did you end up going with?

I have a vintage Gardin TT frame that's my pride & joy that uses Italian threading and the thought of ever stripping the BB on that frame scares the living daylights out of me...luckily I used a high quality BB and installed it perfectly (didn't even loosen up on me as they usually do!). Hopefully I'll never have to take that BB out for as long as I'm alive, but if I do, and something happens...I will remember Phil Wood.

Will post pics soon! BikeForums won't let me until I've hit 10 posts

Do it, won't be any trickier than what you did to remove the old BB, and worst case you end up using a threadless BB.

...+1. With a piloted set of taps and handles, it's really not that hard if you pay attention to getting them on the proper side and starting them in your existing threads.

+1 Door #1
Very probably a face and chase is all you need. Of course I can't say for certain without it in front of me, but it's unlikely the threads are so screwed they can't be salvaged. Obviously, you need the tool and a non-gorilla mechanic that knows how to use it.

+1 also on a modern cartridge BB. It will help keep things aligned going in. The no maintenance aspect is good too.

I suggest blue loctite as well, at least on the fixed side, maybe both.

So here are the pics!





free site to upload pictures

Upon further inspection, a couple of the threads farther into the BB seem to be in rough shape...still think this can be chased?

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...I would probably just install a new sealed unit with plastic cups, which will sort of deform a little and ride over those bad threads, and not even bother to clean up the threads. But I am living on the edge here.

Looking at pics, this isn't as bad as I thought.

I'd go with the chase/face option if you don't feel confident cleaning that up directly.

Yeah, that looks perfectly salvageable by a face and chase.

I totally disagree with the previous poster. DO NOT cram a plastic BB in there without fixing the cross threaded damage to the threads. It is likely to try to go in cross threaded like the previously improperly installed BB. For that matter in this case I would try to use a BB with metal threads.

Now I'm curious. If you threaded this to Italian would here be much metal left in the BB shell? I haven't measured the typical BB thickness but I'm betting the answer is no.

Sweet! Good to know

And yeah I wasn't about to try and install anything in that shell before first trying to get the threads in good shape.

The frame was free so I don't mind spending a bit of money on a proper chase & face. It's definitely still worth it when you compare the cost of having the job done to the value of the frame itself.

I might try that with a salvaged BB on a department store beater, but not this one

After taking a look at these replies, I think I've ruled that option out...way too risky for that reason and others.