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.

Cartridge Bottom Bracket Removal

Cartridge bottom brackets started to replace the adjustable types back in the late 80s/early 90s, so these are much more common on bikes with indexed shifting. If the bearings have a ton of play or make clicking sounds as you pedal, then the bottom bracket is toast. I can show you how to remove and replace a cartridge bottom bracket in this little tutorial. First you need a crank puller, a bottom bracket tool, and something to remove the crank bolts (this procedure is impossible without the right tools, but very easy if you have them). You'll probably also want a nice big wrench or breaker bar for leverage with the bottom bracket tool. Well let's get started:

First remove the crank bolts. This bike uses 8mm Allen bolts (a 5/16" Allen key also fits, but might strip them under high torque due to their looser fit).

Now with the bolts removed you can see the threads for the crank puller to screw into:

Thread the crank puller all the way in and remove the cranks:

Now it's time to use the bottom bracket tool. It's a large tool with 20 splines to fit most bottom brackets (there are exceptions like Phil Wood or Shimano Dura-Ace/XTR, these need something special). I like to put a big 15/16" box end wrench on the tool, but use whatever you like for leverage. I loosen up one side first:

Then remove the other piece:

Keep in mind that the drivetrain side is probably reverse threaded. Now just remove the piece remaining in the frame (I don't think it matters which piece you remove first) and you're done. Here are all the pieces that I removed (along with the tools I used):

The bearings in these cartridge units are generally not serviceable, so you just replace the whole cartridge if they go bad. Here's what the bearings look like with the dustcap removed:

A replacement bottom bracket goes in the opposite way, just clean and grease the frame's threads and put lots of torque on the main piece. The little plastic cup on the other side only needs to be snug tight. You shouldn't have to adjust anything, provided that you used the same size replacement.



There are 3 variables when buying a replacement bottom bracket: thread size, bottom bracket shell width, and spindle length. Most frames are English threaded (1.375"-24tpi) with 68mm wide shells (some mountain bikes have 73mm shells, and Italian frames are 70mm). Your crankset, however, determines the spindle length instead of your frame. Remove your bottom bracket and measure it to verify all of its dimensions before you buy another one to be sure you get the right size replacement.

Wrapping Handlebars

Wrapping handlebar tape on drop bars is pretty easy, but I'll show a few tricks to give you a more professional look. Start by removing any old tape and cleaning the bars:

Next measure a piece that's just long enough to cover the back of the brake lever and stick it in place:

Before you start wrapping the bars it's a good idea to cut an angle in the tape so that there won't be a big bump where the tape starts. This also ensures you won't have a bare spot on the bottom of the handlebars.

Now you can start wrapping. I like to start from the bottom and work my way to the top. It's a very good idea to wash your hands right before you start to avoid getting the tape dirty and contaminating the sticky backside of the tape.

 

It's also very important to keep tension on the tape the entire time that you are wrapping it around the bars. If you wrap it too loose then the tape will shift around and unravel. Try to overlap the tape by the same amount for a neat professional look:

Now comes the tricky part. Once you get to the curved section of the bars you have to overlap the tape much more. This is to prevent a gap from showing on the outside of the curve. When I get to the brake lever I like to just continue wrapping around the extra piece to make it look like it's a continuous part of the tape:

Again, the tape must be pulled tight around the curves because this is the most likely place for it to shift around. It's a good idea to check for gaps on the outside part of the curves now since you can still easily retape it. Once you get to the end you should cut another bevel into the tape:

After that you just need to pull the tape nice and tight and secure it with lots of electrical tape (or finishing tape if it came with your kit). Here's the completed result: