四 川 铁 FourRiverIron

Many bearings not in cages

Many bike axles do not have their ball bearings in cages. The ball bearings are just placed in there by themselves without a cage to contain them.

You can pick up a single ball bearing by dipping your finger in grease and then touching the bearing. Then take the bearing and insert it into the axle.

Bearing guages

When you lose a ball bearing you have to figure out what size you need to replace it.

Ryan said that bearing come in 1/32 of an inch size increments.

They have a bearing gauge that you can use to measure an existing bearing to find out what size it is.

The one Ryan showed us was like a foot long rulers. But the edges are not used to measure the ball bearings.

In the center of the rulers were a bunch of holes and you shoved the bearing thru a bunch of holes till you find the smallest hole it will fit thru.

The bike I worked on last night was using 1/4 inch bearings.

Rear gears are interchangeable

I was kind of surprised but all the gears on the rear wheels are interchangeable.

The bike we worked on had the freewheeling gear on the front instead of the rear.

We took the gear from the rear wheel and threw it away and replaced it with a gear we found on another wheel.

Remember the gears are ALL interchangeable.

Two styles of rear gears

There are two different styles of rear gears and they are taken apart slightly different. It is too hard for me to describe the differences here. Mainly because I don't remember. But basically once you start playing with them they are both easy to remove from the axle.

The main reason to remove the gears from the rear axles is so you can replace the bearings on the rear axle.

Both type of gears have the same basic type of hex socket to remove the gear with. But one gear uses a 2nd wrench that has a chain on it and looks like a plumbing wrench to twist pipes with. A monkey wrench with a chain on it.

You don't rebuild the rear gears

I thought we were going to take apart a rear gear and rebuild it. But Ryan said that they are a pain in the butt to rebuild and you usually just throw then away when they stop working and replace them with a new set of gears.

He did say they do have special tools to allow you to do that, but they don't do it here.

Derailleur / Derailers

Bike Chains

Most 10 speed bikes do not have master links on the chain because the master link interferes with the derailer.

The showed us a couple of tools to remove any link on the chain which you need to do you you want to remove the chain.

Worn out chains and gears

Over time your chain "stretches". It really doesn't stretch, but it appears to get longer because the pins that hold the links together get worn and the chain become longer.

Also at the same time the gears on the front and back also become worn.

The teeth on the gears start out as squares, but as they get work look like sharks teeth and become very sharp.

Worn out chains and gears is not a problem if they become worn out together. They become mated to each other

The problem is when you mix a worn chain or worn gear, with an unworn chain or unworn gear.

That sometimes causes the problem where the pedal seems to be slipping.

Some people like me don't change gears and the chain become worn and only the gear that you always use becomes worn.

This will cause problems only when you shift and start using a gear you don't normally use.

You determine if a chain is worn by measuring it.

They showed us one tool to measure the chain and determine if it is worn.

A better way is to measure the hold chain to see if it it is too long.

Measure the chain, divide the measurement by the number of link in the chain and that will tell you if it is worn.

I think they said most chain links are 1 inch.

Adjusting the derailleur or derailer

Both the rear and front derailleur have two adjustment screws on them.

They are limiting screws.

One screw limits the direction the derailleur can move the chain in the direction of the smallest gear.

You want to allow the derailleur to move the chain to the smallest gear, but not past it.

When you adjust the derailleur for the smallest diameter gear remove the wire cable that moves the derailleur.

Then allow the derailleur to move to the smallest gear but not any farther.

The other screw limits the direction the derailleur can move the chain in the direction of the largest diameter gear.

You want to allow the derailleur to move the chain to the largest gear, but not past it.

If the derailleur move the chain past the largest gear into the wheel it can cause major problems.

The wheel can lock up. But since it is the rear wheel it probably won't throw you off the bike like it did to me when the front wheel on my bike locked up.

The chain can rip spokes from the rear wheel.

When you adjust the derailleur for the largest gear you DON'T remove the wire cable that moves the derailleur like you did when adjusting the smallest gear

Then allow the derailleur to move to the largest diameter gear but not any farther.

Adjusting the shifting levers

The older levers used to shift gears are called friction levers. They just move and don't have any notches for any specific gear. (Ryan didn't says it, but I think any levers like this, such as the levers used to quickly release your wheels are called "friction levers")

They are easiest to use or perhaps better said easiest to adjust because you don't have to adjust them.

The newer shifting levers and things have a notch or slot for each gear.

They are a pain in the butt because you have to adjust them so that each notch adjusts the chain correctly for that gear.

I left early and didn't hear how to do that task.

Ryan says he likes the older friction shifting levers because they are simpler to use and more important because you don't have to adjust them.