Bicycle Mechanics - Bottom Bracket Service/Replacement
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09-27-12, 10:45 PM
I have a 1990 Trek 1400 that needs to have its bottom bracket serviced; maybe even replaced. The bike has almost 30,000 miles on it, has never had anything done to the bottom bracket and there is some obvious play in the spindle. While it has been regulated to my back up bike for a while, I would like to see if I could repair it; primarily for the learning experience. Below are some pictures of what the bottom bracket looks like. I am hoping that someone can confirm what bottom bracket I have from the pictures as well as what tools I need and what I can replace it with.
The bike has all 105 components. The cranks are stamped FC-1055. I am assuming the BB is a Shimano BB-1055. Though the second picture may not show it well, there are two flat edges on the lock ring on the drive side. From Sheldon Brownís website I think this is a standard British/I.S.O. 3-piece BB with a shell width of 68 mm and a spindle length of 113.
From my research I know I need to buy a crank puller and a lock ring wrench. For the crank puller would this one work?
For the lock ring wrench, it looks like I would need: http://www.parktool.com/product/crank-and-bottom-bracket-wrench-hcw-5
As far as servicing, I going to assume the Trek 1400 bottom bracket cups are probably pitted and rusted. I have looked but I canít seem to find any places that even sell 3-piece bottom brackets anymore. I plan on trying to clean and grease the BB but if I need to replace the bottom bracket, what are my options? Can I even buy replacement parts for a BB this old? Or can I replace it with some newer technology like a cartridge BB? If so, from where and what would you recommend I purchase?
There's no reason to assume the BB is toast, so you won;t know until you field strip it and see what's inside. You can still get this type of BB if you look around, (I have a few to sell) or you can replace it with a cartridge BB from Shimano, Tange and others. Just match the spindle lenght and offset (if any).
09-28-12, 07:59 PM
So based on the simplicity of FBís reply and the lack of other responses, I think I may be over thinking this. I done a lot more research and have come to the following conclusions:
1. Try to clean up the original bottom bracket first. Donít assume it is shot. You wonít know for sure until you get apart, cleaned and inspected. Every effort should be made to reuse the original BB as it is by far the easiest solution as well as the least costly and risky. Especially if the fixed cup decides it does not want to come off.
2. If it does need replacing, it can be replaced with a cartridge BB. There are quite a few to choose from. What I have to do is simply make sure it fits. Since there appears to be pretty good evidence that this is a Shimano BB-1055, I have to make sure I get a BB with threading of 1.370Ē X 24 tpi, a shell width of 68 mm, a spindle length of 113, chain line of 43.5 and a spindle that accepts square taper cranks (J.I.S. standard). What I donít know is if the BB is symmetrical or asymmetrical. I can verify all this once I get the BB apart.
Does this sound about right? I apologize if I appear a little dense. This is the first time I have messed with a bottom bracket and all the numbers can be intimidating.
09-28-12, 08:07 PM
sounds good. It may just need some cleaning and fresh grease.
09-28-12, 08:29 PM
IF you have to use a replacement cartridge, don't worry about offset. You can't do anything about that anyway.
Just get one for 113MM.
Fwiw, i have the same bike - 1990 Trek 1400. :thumb:
Over a decade back, I too had BB spindle play. IIRC, I replaced the ball bearings and repacked it with new grease (Phil Wood). That solved the problem nicely and it has worked flawlessly ever since.
Earlier this year, in a (not really uncommon) moment of OCD weakness, I replaced the cranks to a later model 170mm Shimano 105 (so that all my road bikes have the same crank arm length) and used the appropriate Shimano (Octalink) cartridge BB.
However, its gone through other upgrades over the years as well, including a threadless carbon fork, and STI brifters. Here she is in her latest iteration:
I was primarily a MTBer in my former life when I first got her, and when I rediscovered cycling and embraced being a roadie, I had bought a new primary road bike, so my Trek only has single digit thousands on the odometer.
09-30-12, 10:43 PM
I bought a crank puller today and started taking the bottom bracket apart. Everything came off easily, except for the fixed cup, and surprisingly the cups appear to be in excellent shape. I have inspected/cleaned everything and should not have to replace the BB with a cartridge. I am only going to replace the bearing races and grease everything well. Since I am unable to get the fix cup off, I will take Sheldon Brown's advice and just leave it.
Drag, your 1400 looks very nice. You have done the major upgrade of the front end that I always wanted to do, and it looks like you have done a great job. Your upgrades look so nice that they look like original equipment. Very tastefully done. I am surprised you still have the original wheels on the bike though. I went through two rear wheels (stress cracks at spoke holes) replaced under warranty before I replaced the rear wheel with something much more stout to handle the 235 lbs I weighed at the time. Other than the rear wheel, the 1400 has been a great bike. A little heavy but everything else on it has proven to be bullet proof. My son rides mine now more than I do, but for sentimental reasons I could never part with it. Here is a bad cell phone picture of mine.
It is a great bike. At one time, these were Trek's top shelf all-aluminum frame road bikes. Above these you got into the aluminum/carbon frames (2xxx series) and beyond that was the all-carbon frames (5xxx series) made legendary by USPS. Im actually quite fond that this frame (and even the Matrix brand rims) were made right in Trek's Waterloo, WI, facility.
Here she is in her original form from years ago:
I never had problems with the wheels, but I hover around 155. I repacked the original 105 hubs when I did the BB, but theyve been problem free. Im actually surprised the anodizing has been retained on the rims for as long as they have.
Its pretty much a backup/rain bike nowadays, but the ride is comfortable and she still fits me perfectly. People get impressed when I tell them its only 7speed and 22 years old.
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