Sticky Shift Cables

I noticed that the shifting on my Fuji was pretty sluggish today.  Last year I made the mistake of using wheel bearing grease to lubricate the rear derailleur cable. I normally use motor oil and reapply it every few years, and I never had problems with oil. However, the grease that I put on the cable must have gotten thicker while sitting over winter because there was a lot of resistance.  Anyway, time to fix my mistake.

First unscrew the cable pinch bolt:

 

 

Next pull the cable out of the derailleur and cable housing:

If you are putting a new shift cable on your road bike, then this is where you can pull it out of the shift lever:

 

I didn't need to change this cable, however. I just needed to slide the inner wire out of the housings so I could clean off the grease and apply fresh oil:

 

After threading the inner wire back through the cable housings, I secured it to the derailleur's pinch bolt and used my fancy crimp pliers to add an end ferrule:

The last step is to adjust the indexed shifting, since I had to unbolt the cable from the derailleur.  I like to shift the chain onto the second largest cassette sprocket, then turn the barrel adjuster on the derailleur until the guide pulley is centered under the sprocket:

Turning the barrel adjuster clockwise will move the derailleur slightly to the right. Turning the adjuster counterclockwise will move the derailleur slightly to the left.

Moral of this story - don't use grease for shift cables.

Miyata Project

I bought a Miyata Triton frame, and I'll take you along with me while I build it. These were lower-end bikes that were only made in 1987. Regardless, the frame is cro-moly steel and very light.

 

I've built lots of bikes with Shimano drivetrains, but never a pure SunTour build.  I have a 6 speed freewheel, a pair of derailleurs, and some stem shifters. Let's make a bike out of it.  After touching up the paint, cleaning, and polishing I was finally ready to start assembling. First, the headset bearings were cleaned and packed with grease:

Fork reinstalled

Original steel handlebars

 

Brake levers and front brake caliper

Rear brake

I'm guessing this bike was previously converted to a single speed.  It came without derailleurs, shifters, missing a cable guide, and had a short chain.  Thankfully the rear derailleur hanger was still intact. I had to get some parts from the bike co-op, like a saddle and seatpost.  I also found a 700c rim and a Suntour XC Pro front hub (noice!). I built them into the nicest front wheel ever:

Time to reassemble the bottom bracket:

Tightening the lock ring:

And bolting the cranks back on:

Now it needs a drivetrain.  I have a SunTour 7 front derailleur and an Alpha 4050 rear:

 

I re-laced my Schwinn Traveler's old rear rim to a freewheel hub so I could use my 6-speed SunTour Perfect freewheel.  The Traveler then got my Fuji's rear rim, and I then made another slightly nicer wheel for my Fuji.  I'm not sure why I went crazy with all the wheelbuilding, but it's winter and there's not much else to do.

Here's the chain installed:

I found a set of SunTour Power Ratchet stem shifters at the co-op.  These has a fine ratcheting mechanism inside that makes the shifting super light and precise.  They are the best friction shifters I've ever used:

With the cables installed and adjusted, it's a bike again:

Finally, some celeste green handlebar tape gives it a bit of personality:

This bike rides super nicely with the lightweight frame, 700c wheels, fancy tires, and SunTour drivetrain. I originally wanted a cheap urban commuter, but I ended up with something pretty special.

Preventing Frame Corrosion

Steel frame bikes are corrosion prone if you ride in winter with salt on the roads.  In an older post, I showed what happens when water doesn't drain out of a frame.  For better protection, you can spray cavity wax inside the frame tubes to ensure it won't rust from the inside.  My Miyata could definitely use this treatment:

My favorite product to use is called Fluid Film, and there is another bike-specific option called Frame Saver.  For my Miyata frame I am just using an old can of 3M Rust Fighter (I don't think this is available anymore).  With my bike completely disassembled it was easy to spray inside of the tubes. However, you can do a good job by just removing the bottom bracket and seatpost.  Here's how I did it:

 

You can also spray the top tube through the opening in the seat tube when the seat post is out of the way.  With the bottom bracket out, there is easy access to the chain stays, seat tube, and down tube:

There are also small holes in the frame near the dropouts, these are very good places to spray:

 

Don't forget the fork:

 

Suntour Accushift Derailleur Overhaul

I bought a well used Suntour Alpha 4050 rear derailleur that could use some help. I have this same model on a 1988 Schwinn Letour, and it shifts very nicely.

Time to take it apart. I'll start with the mounting pivot. It's spring loaded, which is unusual for Suntour. There's a small C-clip that can be pried out with a screwdriver:

 

That clip will go flying. After retrieving it from across the room, you can slide out the mounting bolt and spring:

 

To service the pulley knuckle, remove this philips screw:

 

Now let the pulley cage unwind, and find the right position to slide it out. You need to rotate it just right so that it will slide out of the knuckle:

 

There are 3 positions for the spring beneath the plastic cover, I'll just use the middle one for reassembly.

 

The pulley screws are 9 millimeters. A socket works best for the screw on the back of the cage, since it is recessed into the plastic cage plate:

 

Pulleys disassembled:

 

Exploded view:

 

Now I can clean everything.  For reassembly, I added grease to the knuckles and slid the springs into their mounting holes:

 

Next I reinstalled the mounting bracket by rotating it against the spring and pressing it into the knuckle. Then I secured it with the C-clip (I pressed it in with a flat screwdriver, but it's easier to use pliers).

Now I reinserted the pulley cage plate into the pulley knuckle.  First I had to insert the spring into the middle mounting hole, then wiggle it a little bit while pressing it into the knuckle. The toughest part was installing the cage stop screw while holding the knuckle back against spring tension.

 

Next I reassembled the pulleys:

 

 And screwed the cage back together:

 All done. I considered sanding out the scratches and touching up the paint, but I actually like the worn look.

Single Pivot Brake Caliper Overhaul

My new-to-me Miyata has sticky brake calipers that don't move freely.  These Dia-Compe single pivot calipers are very common on older bikes, and I'll show you how to take them apart to clean and grease the moving parts.

Before getting started, grind down a cheap 10mm wrench so that the open end is thin enough to fit the inner locknut without touching the outer nut. Alternately, you can buy Park Tool CBW-1, which is rather inexpensive. You won't be able to retighten the locknuts afterwards without a thin 10mm wrench, so don't try to do this without that special tool.

First I loosen the two locknuts with my thin 10mm wrench on the inner nut, and a normal 10mm wrench on the outer nut:

A thin washer will be next. Slide that off, and you can remove the brake arms after you unhook the spring from the back side:

 

Keep everything in order. There should also be a plastic washer between the two brake arms, and another washer on the back.

Here's the order for reassembly (left to right):
Acorn nut
Small locknut
Washer
Long brake arm
Plastic washer
Short brake arm
Washer
Spring








Clean all of these parts, and add grease to the washers and the pivot bolt before reassembly:

  

The reassembled brake pivot needs to be adjusted like a wheel bearing. You want the brake arms to pivot freely, but you also don't want them to wobble around because the brake will feel sloppy. I will screw the small locknut on until it is snug, then back off a little bit and check. Then I will screw the outer acorn nut back on:

 

The most important step is to tighten the locknuts against each other to secure the caliper. Again, you'll need that special thin 10mm wrench for this step. Put the thin 10mm on the inner locknut, and tighten the outer acorn nut against it to secure the adjustment (like a wheel bearing, but less torque).

Finally, you can hook the spring back into the nubs behind the brake arms, and then you're done:

 

Simplex Front Derailleur

I've come across a fair number of vintage bikes with Simplex components, but the front derailleur would be made by a different brand.  I read that the original Simplex front derailleurs used a plastic clamp that was prone to breaking, and people would have to replace them when they inevitably broke.  My brother bought an all original 1970s Peugeot from a thrift store with one of these mythical Simplex derailleurs.

Sure enough, there's a crack right in the weakest part of the clamp:

My guess is that these front derailleurs all failed within the first 100 miles or so, and got replaced with whatever metal derailleur that the bike shop had in stock.