Saturday, October 24, 2009






Big problem. Giant Cadex CFR1 crabon fribe (thanks BikesnobNYC) composite frame from the 1990's with an immovable bottom bracket fixed cup. Even worse, it's not my bike so if I break it, I have a lot of explaining to do. It belongs to a colleague who came by the Giant frame, fork and Shimano WH-R500 wheelset and gave me the job of making it into something rideable. I originally built it as a singlespeed as requested. After my friend went on a Sunday ride and just about killed himself coming home into a headwind he decided that derailleur gears would be nice. The centrepiece is to be a $22 Shimano 105 crankset which was probably cheap because it needs an Octalink V1 cartridge BB. I'm not concerned about the tiny bearings because the owner will not be riding 20,000km a year.
The adjustable cup and lockring come out okay, revealing that it has a Campagnolo 112mm spindle. The cups are Dura Ace 7400. However, the dinky little wrench flats on the fixed cup offer hardly any purchase to 40 mm headset wrench or big-ass crescent wrench. Freezing with Loctite Freeze and Release has no effect and I dare not heat it, the frame being crabon fribe tubes bonded into aluminium lugs. I'm more or less resigned to putting it back together and cobbling a 52/40 square taper crankset together out of the parts box. The Dura Ace cups, Campy spindle and ball retainers are in good condition and have a long life ahead of them if serviced every so often and nothing awful happens to the immovable fixed cup.
As a last resort, I get onto the Interweb and Google for "stuck fixed cup".
AUSHTA!
No, not a sneeze. It stands for As Usual Sheldon Has The Answer. God, how I miss him. Over 26 years ago Sheldon Brown wrote an article for Buy-Cycling magazine which he later republished on his website.
The article has instructions for making and using a fixed cup remover tool and after a trip to the hardware store I come up with a pretty good copy.


Top pic is the raw materials and the finished tool. I used a 70x14mm bolt, a matching nut and a 14mm threaded sleeve normally used for joining building tie rods. The sleeve is counterbored with a 19mm drill in a bench lathe so it screws right down to bolt head. As Sheldon said, the bolt head mustn't be inside the fixed cup cuz you need to hold it with a socket wrench while tightening the nut. Bottom pic shows the bolt with a stack of ten spring washers which you'd use if you didn't have a sleeve or the tools or the motivation to counterbore one. Flat washers are too wide to fit inside the cup so use spring washers. Also shown is the tool assembled in a fixed cup.
The nut turns to the right to t-i-g-h-t-e-n which is the direction that an English fixed cup unscrews, s-o-o-o....
The nut tightened up snugly with a socket on a 300mm bar and the fixed cup moved shortly thereafter. Talk about an anticlimax...
The cup was quite unscarred inside or out by the experience. If you were freeing an adjustable cup or, God help you, a French right hand thread fixed cup you would apply a socket to the bolt head inside the bottom bracket shell. A long bolt places the bolt head right over where you can see it.
Anyway, I've acquired a new tool and learned an effective way of freeing old style BB cups. Good stuff!

5 comments:

Unknown said...

mess about, just put the cup in a securely mounted vice and turn the whole frame on the bracket. That will move the sucker!

sladepointbiker said...

Smeetith vice trick works fine. But if you're going to wangle teensy 3mm wide cup flats into a vice you need a vice with perfect jaws, a lot of room around the vice and a frame stripped bare with no fork or handlebars flopping about. Half hour and couple of dollars spent making the tool lets me shift a cup with fully assembled bike in the repair stand and is going to save me a lot of time and trouble when I need it again.
Sladepointbiker

Unknown said...

Bloody hell!
What a small world Mr Howard. I only just realized who it is I'm corresponding with.

Best regards and all that.

Tony Smith

sladepointbiker said...

Well yes, it is a small world. How did you know it was me? The email addy or the leaden literary style? The last time I heard of you was several years ago when you achieved modest fame by teaching some creep that character assasination on Usenet wasn't without consequences. Are you telling me that you have also become a fiftyish born-again bicyclist?
Sladepointbiker

Unknown said...

G'day Peter

Tried to post a longish reply but it got "eaten".

My slightly munged email address is:-

tony/b/smith@gmail/com

Love to hear from you.

Tony Smith