Wheel Building

In an older post I wrote about how I typically build wheels. I thought it was a bit hard to follow, so I'm going to include some pictures this time. First make sure your rim is straight, and that you have the correct length spokes (I like to use a spreadsheet called spocalc to find which length I need). Now you can start lacing the spokes to the rim:

The picture shows the first group of spokes laced to the rim. Basically you just thread a spoke through a hole in the hub flange, and then secure it to the rim with a spoke nipple. You want to skip every other hole on the hub, and skip every 3 holes on the rim (not counting the valve hole for the inner tube). Also make sure the spokes are exiting the hub on the same side, and that you lace them to the holes on the rim that are closer to the side you're working on. Once you have the first group of spokes finished you can start with the second:

The spokes from the second group be laced in the opposite direction from the spokes in the first group. Just how many spokes they cross will determine the crossing number (this wheel is a 4 cross pattern). The crossing number is actually determined by the length of your spokes, so longer spokes will have higher crossing numbers (generally a 32 spoke wheel should be 3 cross, and a 36 spoke wheel can be 3 or 4 cross, so measure your spokes with this in mind).

The spokes in the second group should also twist over the last crossing spoke from the first group as shown above. Now you can lace the remaining spokes in the second group, leaving every other hole empty at the rim:

 

Then you can start the third group. I like to start with the spoke nearest the valve hole to make sure that it's positioned correctly between 2 parallel spokes:

The rest of the third group is laced like the first group, and you should now leave every third hole empty at the rim in addition to leaving every other hole open at the hub flange:

The last group of spokes is laced like the second group. Just remember to twist around the last crossing spoke from the third group. Here is the wheel after lacing all the spokes:

Now is a good time to screw the spoke nipples the same amount on each spoke. I turn them until the threads on the spoke are just barely hidden. This allows me to tension the spokes more evenly later on. I start tensioning each spoke by one full turn each with a spoke wrench:

 

After every round of tensioning I check to see if the rim still spins true (or mostly true, since I'll fine tune it later). I can check this by putting the wheel on a bike frame and watching it wobble between the brake pads. I also have an old fork that I like to stick in a vice for doing front wheels.

To true a wobbly wheel, you need to loosen the spokes on one side of the wheel while tightening spokes on the other side:

This should bring the rim back to center. Don't get carried away, half turn increments are plenty.

Once the wheel is mostly true and the spokes have good tension, you need to stress relieve the spokes. Basically just grab pairs of spokes in your hands and squeeze as hard as you can:

If you're using new spokes, they will probably lose some tension so you'll have to tighten them up again. Basically you need to keep tightening and truing the wheel in small increments until the spokes are nice and tight, and the wheel spins true. This takes some practice (and patience), so don't be surprised if your first few wheels come out wobbly. To verify if your spokes are tight enough, you can pluck the spokes from a good wheel and compare how they sound to the ones on your wheel. Their pitch should be similar (spokes emit a higher pitch as they get tighter).

Quick Release Skewer Disassembled

So I have an old broken quick release skewer lying around and I always wanted to know how these things worked.

This one is held together with a nut so it can be taken apart:

Here are the internal parts. There's an off-center cylinder attached to the handle which turns inside that big hole in the skewer. This moves the skewer back and forth as you flip the lever. Here's a better look at the cam mechanism:

Cool.

Cup and Cone Bearings

Most moving bike parts use cup and cone bearings. This means there are ball bearings sandwiched between 2 angled surfaces which rotate against each other. In this post I'll demonstrate how these bearing pieces fit together. First is the headset:

The headset bearings allow the fork and handlebars to pivot freely against the frame. Here is a threaded headset disassembled:

The frame cups are pressed tightly into the frame's head tube, and the crown race is pressed onto the fork. The top race screws onto the fork's steerer tube to preload the bearings, and the adjustment is secured by the top nut (which also screws onto the steerer tube). There is usually a keyed washer between the top nut and the top race to prevent the headset from loosening.

Next is the bottom bracket:

This bearing allows the cranks to spin freely, and also supports the rider's weight while standing. Shown here is an adjustable English bottom bracket with a square tapered spindle:

Both cups screw into the bottom bracket shell on the bike's frame. The fixed cup is tightly secured on the right side, while the adjustable cup in only screwed in enough to preload the bearings. The lockring threads onto the outside of the adjustable cup to secure the adjustment. The cranks attach to the spindle, which is meant to turn freely inside the bike's frame.

The last bearing I'll show here is the wheel hub bearing. These bearings allow the wheel to rotate freely, and support the rider's weight. Shown here is a rear freewheel hub:

The bearing cups are pressed into the hub shell, and the cones are screwed onto the axle. The ball bearings rotate between these two surfaces, allowing the wheel to rotate freely. The bearing's adjustment is secured by a locknut next to each cone. Here is the hub disassembled:

 

In general, a good cup and cone bearing will last a very long time. You can dramatically extend the life of these bearings by disassembling them, cleaning the bearing surfaces, and reassembling them with fresh grease every few years. The reason to do this is to remove contaminants from the bearings and prevent premature wear from abrasive particles. Additionally on a very old, neglected bike the grease likely has dried up and will need to be replenished to protect the bearings. The type of grease you use doesn't matter very much since bike bearings don't get hot or spin at thousands of RPM. It's best to use whatever is on sale at your local hardware or auto parts store. Automotive wheel bearing grease and marine bearing grease are especially good choices because they are water resistant and typically have extreme pressure additives to protect the bearings against shock.

Mountain Bike Build

I have lots of mountain bike parts lying around so I thought I'd try to make a bike out of them. First I bolted the saddle to the seatpost clamp:

Next I installed the seatpost clamp and seatpost so the frame can be clamped in a stand (or just set upside down on my basement floor):

To install the cantilever brake arms, first grease the outside of the studs and then slide the arms on. I usually use the middle hole if there's more than one position for the spring to attach to, unless the spring tension is way too loose or tight:

 Screw in the mounting bolts to secure the brake arms, but don't overtighten them to avoid damaging the studs (it's a good idea to use threadlocker on these bolts, and they often come with it from the factory):

To install the bottom bracket, first grease the threads on the main piece and screw it in part way:

 

Next screw in the plastic spacer part way (no grease needed here):

 

Now you can torque down the main piece all the way. It has to be really tight:

Finally just snug down the plastic piece. It's only a spacer, and if you overtighten it then it will crack.

Now slide the cranks on:

And bolt them down. These need to be pretty tight as well:

 

Next I installed the derailleurs. The bike frame already had a Shimano Hyperglide chain installed and I don't have any replacement pins. I'll show you how to install the derailleurs without breaking the chain:

For the rear derailleur you just remove the tension pulley, then wrap the chain around the guide pulley. You might need to rotate the inner cage plate in order to slide the chain in:

 

 Position the chain as shown then reinstall the tension pulley:

Simple enough. The front derailleur is even easier. Once you remove the cage screw you just need to carefully spread the plates apart and slide the chain through:

Now reinstall the screw and you're set:

 

If your front derailleur has a rivet rather than a screw then you'll have to disconnect the chain to install it. Next I decided to install the fork (not the most efficient way of doing things I'll admit). First I cleaned and repacked the headset bearings with grease:

Next I slid the fork through and tightened the headset:

Once the headset was properly adjusted (no play, minimal turning resistance), I installed the handlebars and stem:

Then I installed the cassette onto the rear wheel and put the wheels on the bike:

Starting to look like a bike now. Now the fiddly stuff. To position your shifters and brake levers on the handlebar, hold the grips next to the bar to find the right position for the levers:

Once you tighten the levers down you can start installing the cables. On these Rapidfire shifters you need to put the shifter into the slackest position (gear 7 on the right, gear 1 on the left), then slide the cable through the hole:

For the brake cables you will need to hook the barrel end into the brake lever, then slide the cable through the lever. These have a slot running through them that makes this so much easier:

Now cut the housing pieces to the right lengths and slide the cables through them. Oil the cable before threading it through the housings. Finally bolt the brake cables to the brake arms:

 

And bolt the shift cables to the derailleurs:

Now you have to adjust the cables. There are barrel adjusters on the brake levers, shifters, and the headset bracket for putting the optimum tension on the cables:

 

Adjusting indexed derailleurs can be a little tricky. First make sure the limit screws are correctly adjusted. For the rear derailleur you should adjust the cable so that the guide pulley is centered underneath each selected gear. If the shifting is still hesitant then you can make further adjustments with the barrel adjuster. On an indexed front derailleur, the barrel adjuster only really works for the middle gear. Try to adjust the cable so that the chain doesn't rub the derailleur cage when the chain is in either the lowest or highest gear in the back. This takes a bit of experience so good luck. Brakes are easier, just unscrew the adjuster until the lever feels nice and firm, and center the brake arms so that they don't rub the rim (cantilever brake pad adjustment).

Once everything is assembled correctly you can install the grips. I like to use hair spray. It gets pretty sticky once it's dry, and it'll lock the grips in place:

Here's the bike I ended up with. The fork I picked out was meant for 700c wheels, so I tried a road bike wheel in order for the brakes to reach the rim.

Is this a 76er? (Edit - I installed a short reach single pivot brake caliper on the rear and built another road bike wheel to match the front. It rides well as a hybrid).

Brake Pad Quick Tip

If you're trying to install new brake pads on a bike and the pad keeps turning with the wrench, put a little grease or oil on the threads before screwing the nut on:

This way the pad will stay in place more easily as you tighten the nut to secure it. This applies to older side-pull and centerpull brakes, as well as modern V-brake pads (basically any pad with a threaded post).

Seatpost From Hell

I've never run into a seatpost seized this badly into a frame before. It was a beautiful SR fluted aluminum post stuck in a steel bike frame. The post was inserted most of the way into the frame without any grease (the previous owner might have even used epoxy glue for all I know). I tried every method I could think of: sticking the post in a bench vise, putting an adjustable wrench on the clamp and standing on it, soaking it for days in ammonia, penetrating oil, rust remover. I even used a propane torch to heat it up and then rapidly cool it in a bucket of water over and over again to see if that would break the corrosion. Nothing worked. After several days with two people fighting with it this was the result:

The top of the seatpost eventually broke off. The post was a solid casting, and really strong. I really wish I didn't break it. Next I tried the hacksaw method. I drilled a 5/8th" hole to get started:

The most tedious hour of my life:

After using a hammer and chisel:

Found a bigger drill bit:

Leftover shavings:

Vise time, maybe it'll work?

Darn. There's just way too much seatpost left in the frame to remove it. My last resort was to use lye to dissolve the aluminum (warning lye is extremely dangerous, don't touch it, breath it, stare at it for more than 8 seconds etc. Wear rubber gloves, eye protection, body armor, oxygen mask, fire suit etc.). After 2 days the seatpost is still intact. I was expecting it to dissolve rather quickly but it looks like it's going to take another week to remove.

Edit- Here's the post after soaking in lye for 4 days:

I managed to pry out the top 2 inches, but there's still a small collar left deeper in the frame:

Time for more lye. I've been sealing the top of the seat tube lug with a cork and pouring the lye in through the bottom bracket shell. So far it's working very slowly, but at least it's working. The post gets thinner every day. You can also see the damage to the seat clamp from all my hammering and prying to get the post out. I hope that it will bend back into shape later.

Edit- I finally got the rest of the seatpost out after soaking it for 5 days. The lye made the remaining piece thin enough that I could pry it out with a hammer and a thin screwdriver. Here's my trophy:

 

I learned a few things during this process. The hacksaw method works best on a thin seatpost that's not very deep inside the frame. Ammonia is useless. Spreading the seat clamp lugs will only damage the frame. In my case (thick seatpost set deeply into the frame) the only good way to remove the post would be to clamp the frame in a secure stand and drill it out with a 1" drill bit. The lye was a good second choice since I don't have a large enough drill bit, but it's messy, slow, and damaged the paint on the frame. I'm off to find a new seatpost now, cheers.