Shimano Uniglide

Lots of 80s bikes have a unique type of cassette that uses a threaded cog on the end to secure the gear cluster to the hub. This is called uniglide, and was Shimano's first attempt at making a cassette hub. These cassettes have twisted teeth, without cutouts or special shift ramps. Here is a very early 6 speed uniglide cassette hub from 1982:

 

Notice the threads on the outside of the freehub body. These are for the last cog which holds everything else in place. To remove the cassette you can use 2 chain whips to unscrew the smallest cog, or you can leave the wheel on the bike, shift into the biggest gear, and put the chain whip on the small cog. If you pedal forward with the chain whip secured in place, the cog will unscrew.

The last photo shows the complete cassette. Notice how there is only a dustcap at the front of the freehub body. This means that you can't install a modern hyperglide lockring to this freehub body. Some late 80s/early 90s hubs have threads for both cassette types. 

There are lots of ways to modify a uniglide cassette hub. The threads on a uniglide hub are the same as a standard freewheel, as well as a bottom bracket lockring. If you lose the smallest cog you can still use a bottom bracket lockring to hold the rest of the cassette to these hubs. You can also add a track cog to these threads to make a cheap singlespeed bike. Also keep in mind that uniglide cogs can be installed backwards if they wear out, thus doubling the life of the cassette.

Finally, you can install a newer hyperglide cassette to a uniglide hub if you grind off part of the wide spline on each gear (Hyperglide cassettes have one spline that is thicker than the rest in order to line each gear up with the shift ramps on adjacent gears. Uniglide cassettes have a uniform spline pattern). If your hub doesn't have the inside threads for a hyperglide lockring, you can just omit the smallest cog and use a bottom bracket lockring to secure the cassette. These hubs have lots of little quirks to them, but are definitely worth keeping around if you find a bike with one.

Starter Motor

Remember when this blog used to be about bike repair? Well I haven't had to do any major repair work on my own bikes yet, so here is an automobile starter that I took apart (I need a life..). In case anyone cares, it's from a 3.0 liter OHV Ford Taurus motor. These are ridiculously easy to replace since they're held on by 2 easily accessible bolts. Don't get me started on the DOHC motors though ...

Here's a better shot with the brushes removed:

 The solenoid can be taken apart too but it's really not that interesting. It's just a magnetic on/off switch. When its "on" the starter will rotate. When you turn the ignition key, the solenoid activates the motor and your engine can start.

I got bored today

Ever wonder what a 25 year old oil filter looks like inside? Here's an old AC Delco PF-47 that's been in my garage as long as I can remember:

It looks like it belongs on a World War II fighter plane. Here's the filter cut open: 

The paper inside looks messy cause I was trying to pull it out. Here it is in all its glory:

Looks pretty good despite me hacking it to pieces. Anyway there's more bike related stuff on the way, possibly with better photos (stupid cellphone camera).

Stripped Pedal Threads

(Yes, that's a spark plug.)

If you strip out the threads in the right hand crank, you can use a 14x1.25mm spark plug thread repair kit from a car parts store to fix it. Pedal threads are normally 9/16-20 tpi, but the metric size is actually close enough to work. If you strip the left hand crank, you can theoretically still use that kit but you'll need another right hand pedal and some threadlocker (you're better off just replacing the left crank).

Rust Removal

There's a really easy way to remove mild to moderate surface rust from steel. You simply rub a piece of wet aluminum foil over the rusty part and it should become shiny again. This works especially well on chrome parts.

Rusty:

 

 

  

Shiny :)

Happy Halloween!

Here are some random pictures I've snapped while on my bike.

 

Happy Halloween

Repacking Wheel Bearings

Here's a quick tutorial on repacking wheel bearings. Generally you should do this every couple of years if you ride regularly, especially if you ride offroad and your hubs aren't well sealed. Old bearings definitely need this because the original grease dries up and doesn't protect the bearing surfaces anymore. This tutorial shows a rear cassette hub. Front hubs are very similar, just skip the part about removing the gear cluster.

First you have to remove the cassette. You will need a cassette lockring tool and a chain whip.

Shove the lockring tool into the cassette and put a big wrench around it (the one shown is a 15/16" size, otherwise use a big adjustable wrench or a 1/2" drive breaker bar). Next push down on both tools to unscrew the lockring, this may need a lot of effort.

For freewheel hubs, insert the specific freewheel tool into the freewheel and wrench it off with lots of force, being careful not to let the tool slip. If you have a prong style remover, use the quick release skewer or axle nut to hold the tool tightly in place as you break the freewheel loose (Here's a quick tutorial to remove a freewheel).

Now slide off the cassette and place a cone wrench on the flat sides of the axle cone (the inner piece) and put an adjustable wrench tightly around the outer locknut:

 

After removing the nut and spacers, unscrew the cone. Be careful, since little ball bearings may fall out as the axle gets looser. Also keep track of the order of those spacers, especially if your hub has rubber seals on the outside. 

 

Now remove the axle and all the ball bearings inside the hub. There should be 9 per side on most rear hubs, and 10 per side on most front hubs. Use a small screwdriver, needle nose pliers, or a toothpick to get the balls out. Clean every bearing surface thoroughly, including the cones, ball bearings, and the cups inside the hub.

Now pack the hubs with bearing grease and place the correct number of balls in each side. I use either marine bearing grease or automotive grease because they're really cheap, waterproof, and quite frankly better than anything that's specifically made for bikes. Using petroleum jelly like vaseline will eventually ruin the bearings (don't ask how I know..).

 

Now carefully slide the axle back in place and secure it with the cone that you removed earlier. Just hand tighten it, it's ok to leave some play in the axle for now.

Replace the spacers and the locknut in the order that you removed them. Now you need to dial in the bearing adjustment. For wheels with nutted axles you simply adjust the bearings until they have a slight drag (you should still be able to turn the axle with your fingers, but there should be no play at all).  

Quick release axles are trickier since there should be a very tiny amount of play when the wheel is off the bike. The quick release skewer will slightly compress the bearings, eliminating this play. 

To tighten bearings quickly, put an adjustable wrench on each locknut and tighten them together:

To loosen, just put a cone wrench on each cone if both cones are accessible. Rear cassette hubs usually have to be loosened from the non-drive side, so if it is overtightened you loosen the locknut, then unscrew the cone a little and tighten the locknut again. Do this in small increments. Check the adjustment with the wheel on the bike and the skewer clamped down. Feel for play in the wheel inside the frame. Finally check the locknut's tightness (nice and tight, but don't overdo it) and you're done!

Chains

Chains need oil. You have a lot of choices, like specially-made chain lube or a cheap quart of motor oil. Thick “wet” oils collect dirt but last longer and protect against rust better, while “dry” lubes keep the chain cleaner but must be reapplied sooner. It’s really a matter of preference, as long as you don’t use WD-40 (it dries up quickly, and the thin oily residue left behind will not protect the chain from wear).

Chain Installation:

New chains are typically too long for most bikes, so you’ll need a chain breaker to shorten it to your drivetrain’s optimal length. For a singlespeed drivetrain, install the rear wheel and loop the chain over both gears. Find the length of chain that would allow both gears to be directly connected, and use the chain tool to press out the selected pin. 

Don't press the pin all the way out, leave it sticking out of the outer plate so that you can reconnect it. A pin that’s all the way out can be impossible to put back in place.

You will use the chain tool to press the pin back in to reconnect the chain. You want the joined pin to stick out the same amount as the adjacent pins. 

Finally, press the pin out very slightly from the opposite side to loosen up the link that you just joined.

On a derailleur drivetrain you can find the optimal chain length by looping the chain over the biggest front and rear gears (not through the rear derailleur). Find the link that would connect them together, then add 2 links (one inch) from there. You can cut and resize the chain like the procedure above. 

Shimano HG chains require using a special pin to reinstall the chain, so for these you would push the old pin all the way out and use the special pin to join the chain. Many newer chains come with removable master links, so the chain tool is only needed to shorten the chain for these.

Cantilever Brakes

If you have a touring bike, cyclocross bike, or an old mountain bike you probably have cantilever brakes. These can be tricky to install, but they're very powerful once properly set up. A common problem is the pad position. If the pads are installed too close to the brake arm, they typically give weak brake performance. Similarly, if the straddle wire is too long then the performance suffers as well. Ideally the pads should stick out as far as possible from the brake arms, and the straddle wire should be as low as possible without touching the tire. This is an example of a good setup:

To change or adjust the pads, hold brake arm in place with an allen wrench while unscrewing the nut on the opposite side with the right size wrench (adjustables don't work well here, use a box end wrench):

This will loosen up the clamp holding the pad in place, and you can now move it around or swap the pad out for a new one. Position the pad so that it lines up with the curve of the rim, and hits the rim squarely rather than on a sharp angle. You also want to angle the pads inward slightly to keep the pads from squealing, and to give the brake a softer feel.

Finally, hold the allen wrench in place while tightening the nut to lock in the pad's adjustment. Pull the brake lever and check to see where the pads meet the rim. The pads should be aligned with the rim, and the shouldn't drag when the brake lever is released. If one side is dragging, then use the spring tension adjustment screw to center the brake arms:

Turning this screw in will pull the brake arm away from the rim, while loosening it will move the brake closer to the rim. You want the brake pads to sit the same distance away from the rim, so adjust this screw accordingly. If the brakes are centered, slightly toed in, and have a strong feel then you're done.

General Notes

• Most bikes use metric bolts, so don’t use English wrenches. Old Schwinns are an exception.
• Keep your chain well oiled and your tires properly inflated. WD-40 is a degreaser and water displacer, not a chain oil.
• Don’t leave your bike outside if you can avoid it. Rain and morning dew will quickly ruin any steel parts (chain, gears, bearing surfaces, cables, etc.).
• Pedals are NOT self tightening, loose ones are self stripping.
• Dish soap is a great degreaser.
• Small bolts are easy to ruin with the wrong size wrench. Use a socket or box end wrench whenever possible.
• Most parts are held on by 1 or 2 bolts; make sure they’re tightened properly.
• Rubbing wet aluminum foil on slightly rusty chrome works wonders.
• Don’t use a hammer.
• Youtube is your friend.

Quick Release:

• Higher quality bikes often use quick release levers to secure the wheels and/or seatpost. The lever screws into a nut, and then flips closed to put lots of pressure on the frame. For most quick releases, screw the lever into the nut until the lever can be closed with resistance starting at the halfway mark. The lever should not be too hard to fully close, nor too loose. Unscrewing the nut will make the lever easier to close, but reduce the clamping force. Tightening the nut does the opposite.

.