dedhed

I used an old brake spring I bent for this. Some of my other favorites are my LED mini mag and Petzel headlamp cuz my eye's just aren't what they used to be.

onbike 1939

An old spoke, bent into a hook at both ends does the job.

HillRider

The almost standard headset press made from a 2' length of 1/2" diameter or so all-thread rod, two nuts and a stack of fender washers works on most headsets.

A headset cup remover can be made from a section of 1" copper pipe capped at one end and cut lengthwise for about 4" into 4 pedals and flared out to make a "Rocket Tool". I tried this using PVC pipe and it worked for one headset and splintered on the second so PVC isn't a good choice.

RubeRad

I use bamboo skewers for tons of things; as a 'pokey tool' as described by cyccommute to open housing lining, to wedge under handlebar grips so I can dribble water inside so I can twist them off, to dig ball bearings out of hubs, and tamp them back into freshly-greased cones, probably more I can't think of.

Also, one time I was fighting an old BB fixed cup, I applied heat by resting the BB in a wide, shallow skillet and filling with boiling water.

Somebody else mentioned layers of tape for brake shoe toe-in, I just hang a rubber-band on the back half of the brake shoe.

Interlocked hose clamps to mount a CREE XML-T6 superflashlight onto my handlebars. The flashlight is a lot longer and heavier than a bike light, but the hose clamps can be torqued down with a socket wrench until it's rock solid.

RubeRad

Pics of both of thsoe aproaches from the blog of legendary frame builder Dave Moulton.

I also like his quick-link removal technique, and here's his DIY hanger-alignment tool/method, but perhaps that's more involved than what this thread is asking for.

RubeRad

Maybe this also doesn't fall within the scope of this post, but I was blown away the first time I learned that the best on-the-road repair stand is the front wheel. Just turn the front wheel 90deg and stand the bike up on it. It's not hard to keep the bike still with some part of your body, and you have great, both-hand access to derailleurs, chain, rear brake, etc. Doesn't work so well for front wheel/brake issues though.

lvolpe

These make a simple feeler gauge when truing wheels.

seedsbelize 

I cut one end off a Q tip, at a steep angle, for the same function.

elcraft

Tuna fish cans, lined with peel and stick Magnet sheet (available from most hardware stores or office supply stores) attached to the bottom will catch any loose ball bearings without a bounce or lost ball- they fit nicely under hub shells, bottom brackets, Freewheels (Pastor Bob!), etc. Best to keep one's electronics away from them, though, just to be safe.

Good old fashioned Toe clip straps make great 3rd hand tools, they will hold the front wheel straight against the Down tube (even with fenders!), they can also be used as a "Parking Brake" when cinched down on the brake lever and handle bar. Plus they are nice (though short) hold downs for a rear rack.

shelbyfv

Old athletic socks are good for the after-each-ride chain wipe. Turn them inside out when they get too grungy. Mascara brush for cleaning cassettes.

cny-bikeman

I use spokes for various purposes, usually by bending the head sideways to form a loop as a handle with a built-in hole for hanging on a tool board.

I damage the threads and screw on a nipple for poking the corner of a rag through a hub tunnel or to help clean out a fixed cup or other hard to reach area.

A session on the grinder brings the threaded end to a point for my "pointy tool" which has a variety of uses - picking road debris out of tires, probing for pits in a bearing cup, opening lined cable housing, marking softer materials, etc.

Leaving the nipple on and forming a larger loop makes a great parts holder when overhauling a bearing, especially for holding parts in proper order and orientation.

Spokes can also come in handy for non-bike uses. The bent head is often very good at retrieving out of reach objects, and two spokes can be joined tail-to-tail for more reach.

reptilezs

for those that make things with spokes, get a wheel magnet and attach it to the the spoke. now the spoke tool has a magnet on it and you can stick it on any steel surface

jdowdy411

Learned a trick where you can use an old wheel (not QR) as a derailleur hanger alignment gauge. The threading on the axle is the same as the der hanger. Added a zip-tie to the rim to make it easier to judge. Basically just see if the two wheels are parallel, then the old wheel provides a good way to bend the hanger back into place. Takes a few times to get it right; but effective enough if you don't want to spend $65 on the park version.

dscheidt

I was overhauling a bb7 caliper recently, and couldn't find anything to turn the outer foot screw (That's the thing the outer pad adjuster turns, it screws into the outer pressure foot, and controls the distance between the outer pressure foot and the drive cam, and thus, the pad to rotor clearance). the manual suggests a shrader valve core tool, which I don't have. I do have BB7 brake pad springs, which have two arms that work like one, at least where no torque is required.

RubeRad

used another bamboo skewer tonight, to clear the crud out of derailleur limit screws, especially the one with its head sunk below flush, a real dirt collector.

RandomTroll

I found a discarded 'tv table' (a folding table to hold a meal while watching tv) made of hardwood. The uprights were 27 inches long, perfect for a dish tool, once I added 2 4-inch wood screws.

I use the table top as a kneading board when I make bread.

dweenk

Another use for talcum powder is to cure sticky brake hoods. Just clean the hoods, apply talc and rub it in. Stickiness is gone.

Wanderer

For removing those hard to undo KMC missing links the first time. A piece of coat hanger wire looped thru the ends of the link, twisted with a pair of pliers to squeeze it together. Squeeze it with a pair of ordinary pliers by twisting, and it easily comes apart. Untwist or cut the wire to remove..

leob1

A section of PVC pipe with a cap on one end makes a great crown race setting tool. Use one that fils the diameter of the race. The cap helps the force on the race even around it if your hammer strike is off center. And speaking of hammers, one of my favorite tools is a dead blow hammer. it is non-marring, and it's easy to control the force of the blow. I've used it with just a tap,tap to set crown races and remove headset cups, to a full arm swing to remove tight lug nuts. And it doesn't bounce back when you don't hit the end of the wrench hard enough.

leob1

Rubbing alcohol on handle bars ends and inside grips makes them slide on with easy, then it all evaporates.

cny-bikeman

We always used Aqua Net hair spray for grips (cheapest. It not only has alcohol that evaporates but leaves a sticky residue that holds well.

TrojanHorse

I used wooden matches to start my nipples on a double walled Al front rim last time - it holds them just enough to get them started on the spoke without dropping the blasted nipples into the black hole between the two aluminum surfaces.

I don't know what expensive tool that replaces though, or I'd probably buy one.

dbg

PVC pipe with a hacksaw cut, ...to keep bladed spokes from twisting.

Bandrada

Just make sure you tell the custy that in order to remove them you will need to use more alcohol, otherwise you might be selling them some more grips.

The dry method works if you take a little more care during installation, and you are careful to keep the ends of the grips in tact.

Reynolds 

Zip ties on fork blades/chainstays to true wheels.
Old oven tray to avoid small parts going missing and/or washing them.