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No Justice = No Peace
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Discussion Starter · #1 ·
What do I need to know? Can an older frame with this type of BB be converted or used with a regular BB? Are ther replacements available? WHat are the strengths and weaknesses? Things to look out for?


Thanks,
 

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Mantis, Paramount, Campy
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4,734 Posts
Some Answers

1) Depends on the frame. Fishers used wider than normal shells that would require them to be machined down. Something like a Klein that used a normal width BB shell should be able to be threaded. If I remember correctly they have enough material left in the shell for this.
2) Replacement parts are readily available. Again depending on the frame they are different but the bearings were a fairly standard size and spindles are still available from Phil, Action Tec, and if you scrounge around at old shops you can dig up Klein or Fisher speced spindles.
3) Strengths: Install it and forget about it. Once its pressed in its in there and shouldnt need service for a decade. Some are easily adjustable, some are not, depends on frame.
Weakness': Only square taper (but what's wrong with that?) unless you get super creative. And it can be a pain to swap axles if you need a shorter or longer one. Again difficulty can be frame dependant.
4) There isnt much to look out for. What you see is what you get. Its a great design/idea in my opinion. If the bearings are good in the frame you have I wouldnt even touch it.

So, what frame are you looking at?
 

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No Justice = No Peace
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1,512 Posts
Discussion Starter · #4 ·
You guys rock

I'm lookingf at a Fisher Mt Tam. Fillet brazed with the original fork. I need a preperly sized frame to hang my 130mm single speed wheel in. I have a Beer-Getter that is way too small fo rme, and I am looking to swap over all the parts. Looks like a good bet here.
 

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~~~~~~~~
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5,932 Posts
One weakness that I had experienced on a few Fat Chances in the early/mid eighties was the BB shell ovalizing(?). I'm surprised no one ever mentions this in regards to the Fats but maybe they cleared it up quickly. I would have to send the frames back and they would braze in some new material and ream it.
 

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Mantis, Paramount, Campy
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Sounds Like A Winner

The Mt Tam was a pretty nice frame.
As long as the bb spins smooth I wouldn't give it a thought.
 

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GoCyco
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359 Posts
You won't be able to use a std BB, as a whole. You could use the spindle. With a square taper spindle you can still run new Campy Cranks.
I have an old Merlin with the Grease Guard BB. It's simply a Ti spindle, 2 pressed-on bearings, and 2 lock rings. The Merlin also has 2 grease ports under the shell for periodic lubing.

Pros - light weight & bearing replacements are cheap.
Cons - can't use the newer BB/Cranks with external oversized bearlings.

Tom Kellogg (who design the older Ti Merlins and continues to build under the Spectrum label) was doing a retrofit on the BBs at one time. If I remember right it was about $300 to convert to the threaded shell. I never did it.

I still have my '91 Merlin Ti and have no issues. Great bike. I retired it from racing in '98 and now it sees use as a commuter. It's fitted with a rear rack and lights and I usually get interesting looks when riding back and forth to work (it's too nice a bike to be a commuter!)

Hope that helps.
 

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Lutarious said:
Are there replacements available?
The bearings should be readily available. As long as it has a spindle of acceptable length in the bike right now, then don't worry about it, you should have no problems.
 

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laffeaux said:
The bearings should be readily available. As long as it has a spindle of acceptable length in the bike right now, then don't worry about it, you should have no problems.
I had an '87 Mt. Tam I ended up tapping out back in the early '90s. It required using an Italian-sized bottom bracket (Shimano cartridge) due to the slightly larger size of the Mt. Tam's shell (Italian bottom brackets are slightly larger diameter as well as being right-hand thread on both ends).

Haven't tried this on my Kleins, but I was considering it on one since the bearings are due for replacement. Sounds like they might be the slightly smaller diameter that would tap with an English set.
 
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