The Golden Wrench

A blog about bicycle repair and maintenance by the mechanics at Freewheel Bike.

Saturday, July 30, 2011

Fun project bonanza!

I've been saving up photos for the past few weeks to compile into one big blog post about fun repairs, so hang on tight...

First, let's reach back a few decades to the Golden Age of two- and three-speed internal hubs. A customer came in with a Bendix two-speed kick-back coaster hub (Yellow Band!) that wasn't behaving itself, even after a couple attempts to service it. So I pulled it apart for diagnosis:

In the foreground notice the Bendix wrench; yes, that one end is a 47/64". After cleaning everything I was able to find the problem--a broken coupler:

Notice the missing section in the foreground, which should be a closed rectangle like the hole on the opposite side (also notice the Sutherland's manual on the bench--trade secret!).

Unfortunately, though we have lots of old Bendix parts, we have long since run out of the fragile bits, so barring some lucky Ebay searches, this wheel will have to be retired.

Next up is a suspension fork that we don't see too often around here, Fox's 36 TALAS, their big-hit, travel-adjust fork. There's all sorts of fun stuff in this fork, including the granddaddy of today's 32 FiT damper forks, the big RC2 damper cartridge. Here's everything laid out:

Lots of stuff going on there! Notice the black rubber bladder in the lower right--Fox was using their FiT dampers in the big downhill forks for years before they finally came out with a smaller, cross-country version for their 32mm forks in 2010. Both FiT systems are designed to reduce weight by minimizing oil volume. Here's a look in the end of the damper cartridge just before the bladder is installed:

Our final stop in Taking Things Apart Funland is an overhaul on an Avid Juicy Ultimate hydraulic brake lever. This brake was exhibiting all sorts of undesirable behavior, including occasionally going all the way to the handlebar without engaging the brake AND pumping up to the point that there was no lever movement. I suspected the master cylinder piston seals, as both of those symptoms suggested oil was getting around the seals. It was also leaking brake fluid from under the reservoir cap, which suggested that the rubber parts in the lever were getting tired. Here's everything exposed to the light of day:

Notice the two threaded pieces on the right--the red part threads against the worm gear below it to provide freestroke adjustment (the point in lever throw where the pads contact the rotor). This is different than reach adjustment, which sets the starting point of lever throw. Though it's becoming more and more common, typically this kind of adjustment is only seen on higher-end brakes, as it adds a lot of moving parts to the system (equals more expensive).

Well, that's all I've got for now. See you out on the trail for the Murphy Time Trial Series!

Tuesday, July 26, 2011

Murphy Time Trials!

It's that most wonderful time of the year! Or it's at least in the top five or so most wonderful times of the year!

The Murphy Time Trials have been a Freewheel tradition since around the Louisiana Purchase, when President James K. Polk shrewdly secured Park Place and Marvin Gardens in exchange for his extensive (but, as it turns out, worthless) railroad holdings. The French subsequently went bankrupt soon after landing on the "Go to Jail" square in back-to-back turns, and thus the tide of world power was turned.

Anyways, the trick at Murphy is to go fast and not hit all the roots. They slow you down. The picture below will help:

If you memorize this picture, it will give you a distinct advantage. Take special note of where all the roots are. I went ahead and marked them with red dots.

The other key to a good time trial is to have a good song stuck in your head. The theme song from "Hawaii Five-O" would be a dandy, or the finale to "The William Tell Overture." "Volga Boatman" would not do at all, nor "Entry of the Gladiators" (yes, that song has a name!!!), nor "Ring Around the Rosie," especially if you know what it means.

Need some details? Find them here or if you know everything already, you can register here.

See you there!

Thursday, July 21, 2011

On a Bike Guy's Day Off

Some people who work in bike shops get their fill of bikes and bike-related intrusions into their lives at work. My dad was kind of that way. He still rode, but not a whole lot after us kids got bigger and more demanding. He would occasionally take his days off and head up to Levis Mounds, not just to ride, but also to scout for grouse hunting in the fall.

Personally, I'd rather ride my bike than do most anything on my days off, even if it's only for an hour or three. As Kevin says, it's cheaper and more rewarding than psychiatry, and it has the additional benefit of making supper taste extra yummy.

On occasion, I like to take off and do a ride that is well beyond my current fitness level, just to see what's in the tank. Some of those times include ankle chips and number plates, but usually I'm smarter than that and just do it for fun. Today's ride was like that: just for fun.

Murphy Hammerhands, scene of the previous evening's ultra-sweaty shenanigans, served as both the start and the finish venue. I ended up riding Murphy twice, Lebanon Hills, and Terrace Oaks, for about 70 miles on the day.

Along the way, I saw this log that looks like it belongs in Middle Earth. Hungry as I was, I didn't eat the amazing fungus for fear that I would shrink or grow like Alice in Wonderland and my new bike wouldn't fit anymore.

I was hoping this picture would turn out better. Of course you can't see it, but there's a Farmer's Insurance blimp over behind those trees. I think it was just being bashful when it saw my camera.

Yeah, I was still feeling pretty good when I took this picture. I was at the Lebanon Hills parking lot, about to ride the South Metro Dirt Roller Coaster. Afterwards, the bottom-left number was much closer to 40 and I wasn't feeling as chipper.

This is what it looked like from space on a rather blurry day. I crashed, bonked, got rad, helped some dudes fix a flat, cramped, gave out some business cards, ate pizza at Kwik Trip, drank five bottles of water and a Red Bull, and tried to take a picture of a blimp. We'll call it a good day off. Thanks, Google, for the blurry image.

Wednesday, July 6, 2011

Come learn to work on your own suspension fork.

One of our our goals at Freewheel Bike is to encourage the Do-It-Yourself spirit that so many cyclists embody. After all, cycling is a liberating sport and it is what attracts most of us to it. For me it brings back that sense of freedom that I felt as a child when I could get around the neighborhood on my own to go to a friends house or get to school without having to ride the bus or just get out and exploring the local woods. 
    I also remember when that sense of freedom was lost because I got a flat tire or my chain fell off and I had to walk my bike home. Although I'm kind of embarrassed to admit this, that actually happened to me this summer. I got a flat on my way home from work one night and used up my only spare tube. I was pleased that two people actually asked to see if I needed help because this seems to be getting more and more rare among cyclists. The next day on my way to work I got another flat but had not yet replenished my spare tube. The hole was too large to patch and it would not hold air at all, so I started to walk. I think I was passed by about five other cyclists but no one offered their assistance. I have no patience and I wanted to get to work so I just rode my bike the five miles with a flat rear tire. Again, no one even seemed to notice my situation, no offers of assistance came, no one took pity on me, no one even snickered at me for riding on a flat tire (that I saw anyway).
     The lesson here is that you can't count on anyone else to help you if your bike breaks down, not like the olden days when I first got into biking in the mid 90s. You also don't want to be that person that always counts on other riders for help because you neglected your bike. This is why we think that you should learn to do as much of your own maintenance and repair work as you can. And that's why we offer bike mechanics classes at the Freewheel Midtown Bike Center. One area of the bike that people neglect the most is the suspension fork and rear shock. We want to change this so we are offering a Suspension Fork Maintenance Class. The next one is scheduled for Sunday August 14th and will be taught by the legendary B Rose.

Our last Suspension Fork Maintenance class was taught by Tyson Acker. He had two students in attendance.

Tyson stressed good habits like keeping a clean and organized bench.

He demonstrated good technique....

...and he watched over his students like a doting father...

...yet he made sure that they could do it themselves...

Don't be intimidated to sign up for the class if you don't have much experience working on suspension or bikes in general. This class is designed for you.

Friday, July 1, 2011

An eventful day of working at Shockspital

     I spent the day working at Shockspital in the Midtown Bike Center trying to help B Rose and Dave Vance get caught up with the overwhelming demand for our suspension service. The Midtown Bike Center is an unique place with a lot of stuff going on.
     As luck would have it the next work order up was an old Rock Shox Mag 21 from around 1995. This brought back some old memories of my early years of working in a shop. This one had a lot of corrosion but we wanted to save it because it was custom painted to match the bike.

Here it is in all it's former glory!

I started by applying Kroil to all the bolts and the main oil seals and let it soak in.  Then I started slowly and carefully removing the external hardware.

Unfortunately  one of the bolts broke

The tool marks on this crown tell me that someone has worked on this fork before me and that someone was not very familiar with servicing this fork.

There's a large snap ring that has to be removed in order to pull the stanchion and oil seals out.

You used to be able to take these old forks all apart.

Meanwhile B Rose  was working on a Manitou Dorado on the next bench over.
Does anyone remember using the old basket ball needle to inflate your fork? I used one to drain the oil while depressurizing  each leg.

Then it was time to pull the stanchions and seals. You clamp the stanchion using a radius jaw and  unthread that two piece gold and silver seal puller using a 36mm and a 32mm headset wrench.

You have to be careful that the stanchion doesn't slide up and out of the radius jaw.

If all goes well the internals pop out together.

While trying to concentrate on all of this I had to help B Rose supervise Michael.  You see, Michael hangs out at Shockspital so much that everyone thinks he is B Rose' son. B Rose figures that he might as well put him to work.We're not sure if we should pay Michael or send his parents a bill for day care.

I was skeptical that Michael was qualified for the job.

Anyway, back to the old mag 21. If things don't go well the stanchion pulls out but the seals and bushings remain in the fork.

 Oh yeah, this is Derek.

He is putting elastomers on RT Rybak's Proflex.

I had to remove the Mag 21 crown/steerer assembly in order to try to remove the rest of that broken bolt. There was a lot of corrosion on the steerer tube.

But I polished it up.

A couple nice looking packages showed up which meant more work.
 Michael did a nice job assembling B Rose' new work bench.

Unfortunately that old mag 21 could not be saved but I had fun reliving my glory days and seeing all the fun stuff that goes on here. Luckily RST still sells a fork with a 1' threadless steerer and brake bosses. It just won't match anymore.