Join Facebook Group. Table of Contents. You might also like. December 4, July 5, June 30, The 5 best bicycle restoration tips you need to know before starting your first project In this article I will give you the best 5 bicycle restoration tips I wish I knew before I started my first bike restoration project. May 3, Privacy Policy Menu. This website uses cookies to improve your experience.
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Once you have broken it free all that remains is to continue to turn the bottom bracket cartridge and remove it from the bb shell. Once the old bottom bracket is out, cleaning the bottom bracket shell is essential. Get rid of the old grease. A really, really, really. The threads may have been slightly damaged on removal, or simply never been tapped by the installing mechanic in the first place, a heinous sin if ever there was one. Frame manufacturers outsource bottom bracket shell thread cutting to specialists who do a first-rate job.
Still, tapping and facing. That may make seating the bottom bracket exactly into the right track in the threads very difficult. When re-installing the old BB or a new one the result may be a cross threaded BB. A tapping and facing tool is quite expensive. You or your bike shop guy need to take extreme care for this stage. If the bit is not seated exactly in the threads correctly from the very start, you will ruin them.
There will be immediate resistance. If you cut, you will be cutting incorrectly. In this first stage just turn the bits into the bottom bracket shell just enough that they are supported by the shell.
Once the bits are properly seated they will turn smoothly, effortlessly even. Any resistance after this stage, however, means the threads need to be cut. The bit will both rotate easier and cut more keenly. Easy turning will help in spades should the threads really need cutting, which they will if they are damaged. If there is any resistance, this means the shell threads need to be cut. Rotate into the cut for one or one-and-a-half turns. Then reverse direction, loosening off.
Continue to turn the bits into the bottom bracket shell until each is fully inserted. When each bit has reached the limit inside the BB shell, smoothly turn the bits in the opposite direction to remove them. Make sure you get the removal process right. You need to support the tool and the bits as they approach the BB shell edge face and as you remove them. If not then a bit will drop away from the BB shell as it exits and damage the threads at the very edge.
You will be much more likely to cross-thread the bottom bracket as you introduce it to those initial threads since there will be resistance from those damaged threads. That means forcing the bottom bracket threads to sit seemingly correctly in the BB shell. Having successfully removed the tapping tool from the BB shell, you need to clean any detritus or aluminum shavings from any thread cutting.
Give the shell a brush then a wipe with a shop cloth or rag. Applying grease to the bottom bracket shell along with the bottom bracket cup threads is extremely important. At the very least, removing the bottom bracket in the future will be infinitely easier. And there will be less wear and tear. A pair of nitrile gloves for handling the grease is a good idea, especially if you are keen on keeping greasy finger marks off the frame when doing subsequent work.
Give the bottom bracket shell a liberal coating. More is more in this case; no harm done in applying more than you think is necessary. Use degreaser if you have some handy. There are two standards in current use, and there is another used on some parts still seen. The differences can look subtle, until you actually insert a spindle into a crank.
The spindle approaches the bottom of the dustcap hole in this crank. There is a risk of the fixing bolt's bottoming out on the spindle. This crank is at risk of bottoming out on the end of the tapers. The photos below are of Phil Wood cartridge bottom-bracket spindles, which are the same except for the tapers. Note that the shafts of the spindles, at the left side of the photos, are all the same size.
The appearance of the tapers on other spindles may differ. Some older Shimano Dura Ace used a shorter taper than most other cranks. Most modern cranks will bottom out on the spindles from these cranks A practical option to keep J. Short begins with mm. Longer begins with mm. The general rule has always been that the taller the rider—and the longer the leg—so too the crank should be longer.
Or rather, you need to select the appropriate crank, which includes the appropriate crank length, for the specific riding context. You should read it and evaluate the argument for yourself. What is a Square Taper Crankset? The crankset gets the square taper name from the type of bottom bracket to which the crank is mounted. Go to Article. The post gives you all you need to know about square taper bottom brackets including how to remove and install them in great detail. Here are the key points setting the scene for our look into square taper cranksets.
Most square taper bottom brackets come in cartridge form. The unit is seated into matching threads inside the bottom bracket shell, then screwed into the shell. Cartridges are both cheap and durable. When the bearings begin to fail, remove the cartridge and install a new one. You do find square taper bottom bracket setups where the spindle rotates courtesy of a cup and cone with bearings in a race.
The end is actually an octagon since the square edges have been bevelled slightly. The crank is wedged into a tight connection with the tapered spindle through tightening the crank bolts.
How to Remove a Square Taper Crankset. It is crucially important to remove your crankset correctly. The tools required are as follows.
An 8mm allen wrench from your set of allen wrenches is the first. Double up on the 4mm and 5mm wrenches since they are used the most on bikes—brakes, derailleurs, stems, handlebars, accessories.
Gives you extra leverage and thus more control when breaking tight bolts free of their threads, or securely tightening bolts home.
The 8mm wrench is for removing the crank bolts. And re-fitting them later on. Once loose, though, they will just screw out easily. Well, as long as they were installed with grease. A long-handled torque wrench is really useful.
A big wrench like this makes breaking the bolts free of the spindle a lot easier. You just dial the torque setting up to 70 nM or more.
You will need an 8mm bit with a half-inch socket drive for both installing the bolts properly and removing them down the road. Or you can use a smaller tool.
Then extend the handle with a piece of pipe or something like that. A seat post is perfect for this. The essential tool, though, is a crank puller. What is it, how do you use it and what other tools do you need with it? Check out the next section. You can get tool bundles with a crank puller plus wrenches for around seven bucks or so on Amazon.
No excuse not to have one. Ok, sure, you can remove the crank without one. But that relies on impact force and. Good Luck. I think of using impact techniques in bicycle assembly or disassembly as like surgery on the human body.
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