Spoke Replacement

Ever have one of those days when you're going to work on something and expect it to take 5 minutes, but it turns into 5 hours? In my last post I showed how to service a rear hub with a freewheel. I didn't show this however:

The outer drive side spokes were mangled up from the chain jamming into them (a dork disk doesn't seem quite so bad now). Worried that these spokes might snap on a long ride, I decided to replace all 9 of them. I'll walk you through this process in case you have a busted spoke on your own bike. 

The first step is to remove the freewheel or cassette (rear spokes break more often than front ones). Next deflate the tire, and unscrew the spoke from the spoke nipple at the rim:

Here I removed the tire, but you can usually just leave it in place if you're only doing a few spokes. Now measure the offending spoke so you can find an adequate replacement:

You want to measure from the end of the threads to the inside of the curve at the elbow. Generally you can go plus or minus 2mm if you don't have the exact size available. Put some grease or oil on the threads, then stick the replacement spoke through the hub:

 

 Work it around the other spokes and join it to the rim with a spoke nipple:

Finally, put the wheel back in your frame, and tighten the replacement until the rim spins straight again:

That's all, cheers!

Freewheel Hub Bearings

I took some pictures of the freewheel hub on one of my older bikes. I previously did a tutorial on servicing a cassette hub's bearings here, but I thought this could be useful too. First you need to remove the freewheel:

It's a good idea to brace the tool with the axle nut or quick release while you break the freewheel loose, they can be pretty stuck. Anyway once the freewheel is off (more info on removing them here), you can loosen one of the locknuts while holding the axle cone steady with a cone wrench:

Many times on a freewheel hub you can just used two regular wrenches on the drive side, since the locknut and cone are sometimes spaced far enough apart to fit a standard wrench on the cone. With the locknut and spacers out of the way you can unscrew the cone:

Then slide out the axle and remove the bearings:

And clean them well:

I like to use mineral spirits, but it's pretty nasty on your bare hands. Now pack the cups with grease and place each ball bearing back inside. There are usually 9 on each side.

Slide the axle back in place and screw the cone back on:

Then replace any spacers and the locknut:

On this particular hub there are 2 locknuts on the right hand side, so I tightened the inner one against the cone first:

 Then the outer locknut against the inner one:

The last step is to adjust the bearings to make sure the wheel doesn't have play and turns easily. For solid axles you adjust the bearings for no play in the axle, and minimal drag as you turn it (slight drag is preferable to having play here). For hollow axles with quick release skewers you want a very slight, almost imperceptible amount of play because the skewer will tighten the bearings a little bit more.