Sunday, April 26, 2009

Bike Camera Project

During this year's Bicycle Tour of Colorado I want to capture some of the spectacular scenery and downhill runs on video.

I considered both helmet and bike mounted cameras. Both have their advantages. The helmet camera is obviously has the advantage of inherent vibration dampening and tracking the riders point of view. However the helmet cams I can afford lack the flexibility of also serving as a high quality still camera and take only a limited amount of SD memory.

On the other hand there are plenty of 8-plus megapixel relatively inexpensive cameras out there that can also do fairly good video, however I don't think I want them hanging off my helmet.

My worry about the bicycle mounted camera is first finding a secure method of mounting the camera to the bike that won't interfere with normal operation and can be removed easily when not in use. There are several DIY bicycle camera mounts possible but I was unimpressed with all of them. Luckily I found one off the shelf at my local REI store that is near perfect. The Pedco UltraClamp Camera Mount ($24, http://www.rei.com/product/777251 ) attaches to the stem of my bike with just a twist of its set-screw and fits as if it were made specifically for this purpose. The mount also has three points of adjustment that make alignment of the camera simple and quick. This is problem solved, it was on to the second concern.



A bike mounted camera will need to cope with some road vibration that may cause blurred video and possibly even damage to the camera itself. To address the blurred video concern I decided on a test using the Pedco UltraClamp Camera Mount and cheap Casio Exilim 7.2 megapixel camera I already own with a 512 SD card doing 640 x 480 30 fps video. I selected a rough stretch of road that is fast with few stops and some small hills as the perfect test track for vibration. The following video starts on a fairly smooth bit of road for reference prior to turning right on to the test road.

video

Viewing the video you can see that even at 20+ mph on the test road vibration doesn't impact the image quality significantly . A reminder here the video is desgraded in conversion process of uploading to this blog. Now the the 512MB of SD memory provided under 7 minutes of video recording, which is another concern I will discuss later. After about 20 miles on the bike the camera mount remained secure, but there was a minor problem. The camera wanted to twist counter-clockwise on the camera mount in response to road vibration. Basically, it was trying to unscrew itself. I think I can address this either by brute force tighten of the mount screw or perhaps using something like Locktite Blue on the threads. If not then I will need to place a vertical pin on the mount pad to physically stop the camera from turning.

With video quality assured then it was a matter of selecting a camera rugged enough to handle the vibration and unpredictable weather of Colorado. After looking at many-many cameras I decided on the Pentax W60 which is small, rugged, waterproof, and feature packed. The best news is that at the same video resolution and frame rate I used in the initial test, I will have over 6 hours of continuous video with a 32GB SDHC card! While I am not certain how long the camera battery will last, this can be fixed by purchasing an extra battery, if needed. I have the Pentax W60 on order and I will provide a project update after I take it for a test run.

There are a couple of remaining issues that I need to address. When I did the BTC for the first time I decided to camp-out. This worked out fine, except that access to A/C outlets was just about non-existent, so charging devices like cell phones and cameras was impossible. The other issue is how to off the 32 GB SDHC card over the 7 day trip.

The good news is that I may have the charging problem solved with use of a light weight folding solar array that provides 12DC at with sufficient current to charge the Pentax W60's battery(s). I will provide a project update after doing more research. The storage problem is an issue since my Netbook only has 16 GB of solid state hard disk in it, so I clearly need some other mass storage device. Of course I could fix that problem by brute force with 7 32 GB memory cards, but at about $90/card that is an expensive solution. My guess is that I am going to use a small USB powered external hard drive in conjunction with my netbook. More to follow!

Wednesday, April 8, 2009

Overhaul of a Lemond Chambery

A coworker asked me to overhaul his Lemond Chambery last weekend. ( Picture is of the finished bike)

Some searching on the web indicates this bike to be from the late 1990's making it about 12 years old or so.

First inspection showed the bike to be dirty with tattered bar tape and tires rotted by age. Additionally, the shifters were "broken". The coworker provided me with replacement Continental Ultra Gator Skin Rigid Bead tires and a pair of used brake/shift levers he got off of ebay. He left it to my discretion as to whatever else needed replacement.

My first effort was to see if I could restore shift function to the levers and avoid using the lesser quality replacements. The problem was typical where the triggers fail to release the shifter. To address the problem I washed out the brake/shifter assemblies with about half a can of dry film silicone spray lubricant. The result was a brown dirty pool of lube on my shop floor and two working shifters.

Knowing that I was going to replace the brake and shift cables regardless of their appearance, I cut them off and put the loose cable housing aside for re-use since it was in good shape. Once the bike is completely assembled, clean, and otherwise ready to go, I would install Aztec Teflon brake and shift cables. I like the Aztec cables for their low cost, low maintenance, durability, and smooth operation.

I removed the tires from both wheels, removed the rear wheel's cassette, and did a detailed inspection after a very thorough cleaning . I found the wheels were fairly close to being radially and laterally true. There were no cracks, dents, or signs of excessive wear on the rims. The nipples and stainless steel spokes were in very good shape. However, I did find the rim tape on both wheels had been improperly installed leaving gaps exposing the tubes to the spoke ferrules, so I replaced it.

Next, I inspected the hubs' races, cones, bearings, and condition of the old lube. The lube was clean and the parts showed very little wear! With everything looking good, I cleaned the hubs, lubed, and assembled them. Next, I trued the wheels to about 1/2 mm tolerance and less than += 10% variation in spoke tension.

Given the age of the old tires and decided to replace the tubes, as well. One of the things I like to do is dust the inside of the tire casing with talc or baby powder. I think this makes the installation a bit better because the tube can move freely inside the tire during installation and initial inflation. The Continental Ultra Gator Skin has an arrow on their side wall denoting direction of rotation that is easy to miss and people often do. I don't know if it makes much or any difference, but I made sure to mount the tires so they would rotation in the correct direction.

Lastly for the wheels I did something that is too often overlooked. I carefully cleaned, lubed, and inspected both skewers. Since these things hold the wheels on the bike, I think it is time well spent.

The chain was pretty gummed up so I decided junk it for a new SRAM PC850 8-Speed Chain. I really like the SRAM chains for their durability and smooth shifting. The SRAM Powerlink included with this chain will also make future maintenance a bit easier for the owner. With my inspection of the rear derailleur I found the bottom pulley to have a bad sealed bearing. After removing and scrubbing the rear derailleur in solvent I installed the replacement pulleys, lubed the derailleur's pivot points, and reinstalled it on the hanger.

There was a lot of dirt around the bottom bracket and on the chain wheels so I decided to pull the crank arms off to make the cleaning easier. This also allowed me to remove the BB cartridge, inspect it, and inspect the surrounding area. After scrubbing the crank arms, bottom bracket cups, and chainrings in solvent I found them to be in good shape with little wear. The BB cartridge was also in good shape moving freely and smoothly. After cleaning/lubing front derailleur, bottom bracket threads, and cleaning the surrounding area I re-assembled the crank. The cleaning really made the replacement red alloy chainring bolts and dust caps visible.

The pedals had some serious dirt and a bit of rust on them that was probably interfering with the insertion of the cleats. It took some solvent and scrubbed the pedals with a stiff brush to remove the dirt and sprayed them with dry lube. The pedals moved freely and easily on their axles so I skipped redoing these bearings. Overall the pedal came out OK except they were pretty beat up in appearance.

The bike had some butt-ugly Profile Design bolt-on aerobars that would make wrapping the handlebars nearly impossible so I removed them. (Note: they were so ugly I didn't re-install them until after I took the picture above). The fork moved smoothly and freely, but I decide to remove the stem and fork for a couple of reasons. I wanted to inspect the metal steering tube for any damage from possible prior over-tightening of the quill stem bolt and inspect the point where it meets the carbon fiber fork crown. The good news was that after a thorough cleaning the fork and headset looked good. I reinstalled them and made a final adjustment without trouble.

I decided to take advantage of the handlebars being free from the bike and wrap them at this point. With some difficultly I removed the old tape and underlying adhesive. I was a little surprise to see the beautiful Cinelli handle bars had been deeply scored by the heavy handed clumsy prior use of a box or razor knife to remove handlebar tape. Given the bars are heavy aluminum construction and the scoring being at the end of the bars I decided replacement was not warranted. I also removed and replaced the vinyl tape holding the shift cables in place on the bars because it was badly stretched.

When I received the bike it had red/black cork handlebar tape no doubt to match the red anodized replacement alloy chainring bolts, dust caps, derailleur pulleys, and alloy nipples of the front wheel. However, I decided on a black and yellow cork tape with the idea this fit best with the gold lettering on the down tube and fork. Even with the yellow in the tape being slightly lighter in color than the lettering, I still think it was a good choice. With the bars wrapped I reinstalled bar and stem. By dumb luck I had some yellow tie wraps that I used to mount the wireless cycle computer's sensor on the fork which I thought was a nice touch.

Until now I was cleaning areas of the frame as I went, but it was now time for an overall cleaning and polishing of the frame. But after starting, I noticed the once clear chain stay protector had yellowed and looked pretty bad on the refrigerator-white frame. I decided to replace it with a Lizard Skins Carbon Leather Chainstay Protector because I thought is looked kind of cool and offered better protection than the original. After installing it, I finished cleaning the frame and fork with Finish Line Super Bike Wash. This took some elbow grease, lots of shop towels, and patience. I found the white finish was good looking, but showed every smudge and small scratches in the finish captured dirt very effectively. Once the frame was finally clean as I could get it, I finished it with Pedro's Bike Lust polish.

After giving the rear cassette a final scrub and re-installing it, I put the rear wheel back on the bike and made the initial adjustments to the derailleurs. Next I installed the previously mentioned Aztec shift cables, cut them to length, and put on the crimps. Here's something often overlooked when replacing cables. Make sure you turn the adjustment barrels to their minimum position before installing the new cables! This ensures the adjustment barrels will be able to accommodate both fine adjustments immediately after the cable installation and component wear or cable stretch over time.

With the shift cables installed I did some fine adjustments on both the front and rear derailleur to make sure nothing rubbed and both indexed through the gears without trouble. Even with a new chain I like to start out with a generous application of White Lighting chain lube. With the drive train assembled and adjusted I careful lubed each link in the chain.

Next I put the front wheel on and checked the alignment of both front and rear brake pads. Surprisingly the brake pads looked good and were perfectly aligned so all I had to do is install the new brake cables after screwing down the adjustment barrels, cut them to length and put on the crimps. Not previously mentioned was that I had cleaned, lubed, and inspected the brakes themselves when I did the final cleaning of the frame.

Since my goal was to make the bike completely road-ready, I decided to go the extra mile and replace the cycling computers batteries, and add a small frame pump under the down tube water bottle cage. I also equipped the saddle bag with patches, tire irons, spare tube, and spare sensor battery for the wireless cycling computer.

After taking the picture above, I resigned myself to putting the aero bars back on which made me a little sad since it screwed with the good looks of the bike and clean cable runs. With the aero bars on I mounted the cycling computer to them and calibrated it to the new tires.

Here's another thing that is often overlooked by folks working on bikes. I went over the bike one last time checking adjustments, bolt tightness, alignments. This check ended with a quick test ride to verify shifting and braking were 100% good.

The bottom line for the overhaul was $147 in parts (not including tires, cleaning supplies, and lubricant) and about 6 hours of labor on the bike over 3 days. My co-worker was very pleased with the results and accessories I selected.