Friday, July 13, 2012

Bar Spinning With a Brake

   A few posts back I wrote about mounting a cog on the disc brake rotor mounts. This is another project for the same bike. I wanted to put a front brake on that bike, since it's a fixed gear and riding without brakes is dangerous and reckless. Here is what I came up with:

   First off, the old fork had to come off. I'm not sure what the preferred method of removing a fork race is, but I've ben doing it like this for a while and it hasn't damaged the fork, race or tool:

Chisel and a dead blow hammer

A few well placed taps and the race is off and ready to go on the new fork, care of the Pro's Closet:

Niner Reynolds Rigid

In the middle of this, I also replaced the black headset cups with red ones. With the same hammer and a large flathead screwdriver, I tapped out the old cups. 

Tap tap tappy

Not shown is the same process in reverse, the tapping in of the new cups, albiet without the screwdriver, only the hammer. Looks like this at the end:

Black and red!

I wanted to run the brake housing and cable down the steer tube, so that I could do a barspin without tangling up the cable... and Here's how that's done. Drill a hole in the star nut for the cable to pass through:

Making quite a mess

Drill a hole in the top cap also for the cable to go through:

The lower left hole

That's pretty much it. The cable and housing run down through the steer tube, out the bottom and around the wheel, and connects to the brake.

All done!

Back View

Since the cable runs through the steer tube, the bars can go around and around without any problem. Bar spins are popular on bikes with a fixed gear because you can do a wheelie and then impress your friends further by spinning your handlebars around!

Wednesday, July 11, 2012

Heat Dissipation for Shimano Brakes

Heat is pretty much always the enemy. On everything from computers to cars, it's necessary to keep things cool. On a bicycle, the brakes are the source of most heat due to friction. Either rim or disc brakes, both get nice and toasty when under heavy use. The methods for dealing with the heat are pretty cool though. For example, here is a heat sink for an electrical component:

Blue anodization extra

The fins cool the device by dissipating heat into the surrounding air. This passive cooling method that works well for an air cooled motorcycle engine as well. The engine below is covered with fins to handle all the heat from the engine running:

Large V-Twin

On an mountain bike, heat is dissipated on the rotors of disc brakes by adding slots in the rotor. These pull air in and cool the rotor:

Standard 6 bolt rotor

Now for the exciting news of the blog: Shimano has a new set of XT brakes with some sweet finned brake pads:

Teh future!!1!

These fins are on the pads, not the brake, but can apparently reduce the pad temperature by around 50 degrees. That's a great way to prolong pad and rotor life, as well as improve braking! 

Monday, July 9, 2012

Home Made Beer Cocktail?

 Hey, I have this Bully Porter that I'll never drink, and some delicious Coors Light... maybe if I mix them it will some half delicious beer...

The players

The mixture. 

NOPE NOPE NOPE. While this seems sound in theory, it was decidedly not tasty. I think that for a proper beer cocktail you need to have the two mixing beers closer to similar. Lesson learned.

Tuesday, July 3, 2012

Electric Bike Report!

There are a lot of electric bikes out there. Some are purpose built and some are aftermarket parts you add to your current (ha, electric current) bike. I came across this bike at a brewery in Grand Junction, and it struck me as one of the more clean bikes. The controls are pretty straight forward - green means on, red means off, twist to go:

The controls

The guts

What I like about this is two fold: 1. The removable battery (it slides out the back of the rack on the back). You can take the battery in your house or to your desk at work and charge it, maybe even have two so you can have one charging and one in use.  2. The driving motor is in the rear hub. There's not any additional hardware other than a back wheel. This is a modification someone with limited mechanical experience could install. 

Compare to these two purpose built crap chutes:

The Derp 

Derp 2, the reckoning 

Neither of these have visual appeal or functional advantage. With the above system you can convert your existing ride to electric and avoid the ridicule of the cycling community. And, for about $400, it's not a bad investment to kick it around town at a cool 20 mph.

Sunday, July 1, 2012

Betasso Gets Bigger and Bigger!

You may recall a posta  while back about the Betasso Preserve getting an additional trail added called The Benjamin Loop. Read all about it here. I heard rumor from handsome Mark that they were going to connect the North end of the Benjamin loop to 4 mile canyon not a few days earlier. Something like this:


The bright red line is the suspected trail. Then, on a morning ride today I saw this:

Behold! Trail!

Unfortunately, the trail is not yet open to riding. I would have loved to peel off my ride and coast home since I was hurting pretty hard, but alas:

Behold! No trail!

The trail looked pretty well established, so hopefully soon they'll finish and this will be ridable! Way to go Boulder mountain bike building crew!