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Messages - zerodish

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61
Gear Talk / Towards an ergonomic gearing system.
« on: April 12, 2014, 09:54:29 am »
I have every gear shimano makes including the rare 29 and have been making 38 39 and 40 teeth rear gears out of chainrings. What I did was carefully note at what speed I shifted and adjusted the gear ratios so that there was no speed gaps between the gears. The theory is simple at high speeds aerodynamic forces predominate so the change in energy is proportional to the cube of the change in ratio of the gears. At low speeds gravity predominates so the change in energy is directly proportional to the change in the ratio of the gears. So far the best is 39 30 24 20 17 15 13 on the rear. The next gear would be a 11.5 since this is impossible I use a 12. The middle gear on the front is 36. With a crossover a natural shift works out to 15 percent so the high gear would be about 42 which is what I use. This allows me to ride at my normal top speed of 28 mph with a optimum cadence though I can go 50 percent faster with a hill or a strong tail wind.  An optimum shift for the low front gear would be 40 percent this works out to a 26 tooth chainring. If you need more range than this you will have to put up with gaps in the gearing or go to a quad front chainring setup. I have built many of these though they are to wide to shift properly. It is possible to put four chainrings in the space used by 3 now. I think the best touring crank would have a 58mm bolt circle diameter for the inner an 94mm bolt circle for the next gear and a 110 bolt circle diameter for the outer two. This would allow for no gaps in the gearing. Note I use 8 gears with 9 gear spacing which allows me to build dishless wheels. All photos are available on flickr by searching zerodish. 

62
Gear Talk / Re: Making wheels stronger with a mixed spoke pattern.
« on: April 05, 2014, 09:54:32 am »
I can't make this any easier. If you study first year statics you will find you will find a mixed spoke pattern will improve wheel strength by allowing the non freewheel side spokes to achieve a more equalized tension in a dished wheel.  I had the good fortune to find several books on bolted and riveted bridge structures at Powel's techinical books.  A spoke in a flange is no different than an eccentrically loaded rivet or bolt. They all recommend that rivet holes should be placed twice the distance of the diameter of the hole from the edge in this case the flange. I typically find this distance to be 1.5 times or 1 times if your count the counter sinking on available hubs. There is no excuse for this all hub makers should add the extra few grams to the flange. They also recommend holes be placed 1.5 times the diameter of the hole apart. For 36 holes and 2.6 mm diameter hole this works out to a spoke hole diameter of 74 mm. It is true Shimano and Campagnolo rates some of their hubs for radial spokes but not all of them. Campagnolo also puts a weight limit on their wheels of 80 kilograms or 176 pounds. Do you really want this on a touring bicycle?

63
Gear Talk / Re: Making wheels stronger with a mixed spoke pattern.
« on: April 04, 2014, 10:11:08 am »
Actually I did not invent the idea. Frank Berto did an article for bicycling called building a bicycle for an adult female. He did radial right and 3 cross left. He pointed out nearly all of the torque would be transferred to the left side which is under less stress. You are certain to bust a flange with radial spoking.  My wheel idea works best with 36 spokes. A 32 spoke wheel could be built with 3 cross left and 2 cross right however 2 cross will be more likely to break the flange. A 40 hole wheel could also be built with 4 cross left and 3 cross right or a 48 spoke wheel with 5 cross left and 4 cross right with no problems. If you are worried about flange breaking use a large flange hub.

64
Gear Talk / Making wheels stronger with a mixed spoke pattern.
« on: April 02, 2014, 09:32:57 am »
I use spocalc.xls available from several sources. It gives the angle of the spokes as they leave the rim. The wheel shown uses a 542mm rim a 61mm spoke hole diameter 36 holes 24mm center line to right flange and 29mm center line to left flange. If I had built the wheel with 3 cross on both sides the angle would be 5.4 degrees on the right side and 6.5 degrees on the left side. However I used a 4 cross pattern on the left side this gives a 6.2 degree angle. This increases the wheel strength two ways It allows the left side spokes to take a higher load before the spokes go to zero tension. This does happen on a hard bump. A new wheel will ping this is the spokes untwisting caused by the truing process. If you watch a high wheeler bicycle you can actually see the rim go flat on the bottom. It also allow the left side spokes to take more of the torque from acceleration and braking if you use a disk. This will also work on a front disk brake. Use 3 cross on the brake side and 4 cross on the other side. The improvement is only a few percent but it is easy to do and uses standard spokes.   https://www.flickr.com/photos/63373992@N07/13559968714/

65
Gear Talk / Re: Schmidt Dynamos for charging batteries… HELP!
« on: March 11, 2014, 09:42:20 am »
Charging lithium batteries is not basic electricity. They must be charged slow and for a two cell battery the maximum voltage needs to be 8.4 volts. First thing you should do is get a coin cell battery and open it up with pliers. Lithium has a distinct smell you need to recognize. This will not kill you. Lithium batteries will vent if they are abused if you smell this with one of your rigged chargers stop what you are doing and disconnect the charger. Lithium batteries catch on fire. There are generally two types of camera batteries those that charge the cells individually and those that charge them together. If you have the type that charges individually like Sony then you can forget trying to rig something up you have to provide precise voltage to all three terminals. Even with a 12 volt camera battery charger this probably will not work. The computer in these batteries will shut down the battery. If you have the other type you only need to provide voltage to two terminals. You can try this by using a 9 volt wall charger or put 5 AA batteries in a paper tube and hold the wires on with a rubber band. Wall chargers have an icon on them a half circle with a dot that tells you the polarity. Charge the battery by hocking up the positive voltage from the source to the positive terminal on the battery. I recommend 15 minutes. if this works then buy a universal camera battery charger. Universal camera battery chargers are available that take 12 volts. Some of these even charge AA and AAA batteries. These cost $20 to $40. And they will regulate any voltage in and out and alert you if the polarity is wrong.

66
Gear Talk / Re: 9spd-10spd chains
« on: March 11, 2014, 09:08:51 am »
If you are really interested in this topic research the engineering definition of toughness. Toughness is defined by how much energy a part can absorb before failure. So a 9 speed chain with thicker plates and weaker steel in tension could absorb more energy than a 10 speed chain with thinner plates and higher tensile strength steel. Few chain makers will use their highest strength steel in their 9 speed chains.

67
General Discussion / Re: "Protection" necessary?
« on: February 18, 2014, 08:35:04 am »
Good luck with that the parks have had so many problems with the homeless many of them will not allow a cyclist to stay at a campground. That said watch out for snakes coming out of the showers they are attracted to the water. In the dryer areas there are scorpions they like to hide under rocks so be careful what you touch making camp. Scorpions don't like a bunch of commotion so they will eventually leave. Coyotes are not a problem they will give you a wide berth. I've never been bitten by a dog and I chase them back in the yard if they get too aggressive. A hunter took a shot at me on highway 395 I saw it hit the rock face but decided not to hang around and find the bullet.  The drug addicts will grab and run with anything not nailed down I've seen it happen with a cyclist standing a foot from the bicycle. The worlds greatest tourer Ian Hibell said it's best to look poor so the thieves will leave you alone.   

68
General Discussion / 100000 since 1992
« on: February 14, 2014, 09:02:38 am »
A 6000 mile tour last year has put me over 100000 since 1992. It was Arkansas Tennessee Kentucky Indiana Ohio Kentucky Tennessee. Most of this was done on a 1996 mongoose hilltopper. Scenery photos can be found on flickr under the name lapsedmember broken parts under the name zerodish and road hazards under bicyclehazard. I still drive forktrucks but have not needed an automobile since then. At 53 I've not reached my peak mileage yet.

69
Prescott is 10 degrees colder than Wickenburg which is 10 degrees cooler than Phoenix. There is emergency water available everywhere in Phoenix when the temperature gets in the 100's One precaution Phoenix has west nile now and it seldom gets cold enough at night to sleep without mosquitoes.

70
Bicycle travel is allowed on interstate 10 in Arizona and New Mexico. Texas has well developed frontage roads along the interstate so use those. I did highway 165 to Cherokee North Carolina and it looks like a fairly straight shot to Asheville from there. Cherokee is my favorite tourist trap in the United States.   

71
Gear Talk / Re: Looking For Cannondale TX1000 Info - Who Has or Had One
« on: February 09, 2014, 09:17:06 am »
Yes I had one it lasted a year and the dropouts were damaged by the axle to the point the tire rubbed the chainstays. This will be true of any aluminum bicycle. Try to load as much as possible on the front where the dropouts are steel.  A 130 mm OLN will work and I built one using a narrow 6 speed suntour freewheel and a solid axle. The original winner pro freewheel broke the removal tool and I had to take it apart and use a vise to get it off.  There is not a lot of room in the chainstays for a tire so a 1 3/8 or 35mm width is best. Currently 27 inch tires are more available at walmart than 700c tires and if you are going to tour cross country walmart will be your closest source for tires. On the other hand the walmart tires are made by Cheng Shin have a kevlar belt so they work fine. The frame is not super stiff and is actually mushy at the bottom bracket.

72
General Discussion / Re: Weather Data Aggregation for Bike Touring
« on: February 09, 2014, 09:00:11 am »
This is a tool I use on a regular basis here is an example but it is highly customizable. http://www.wunderground.com/wundermap/?lat=35.03744888&lon=-85.30740356&zoom=8&pin=Chattanooga%2c%20TN some times you have to load it twice to get it to work.

73
General Discussion / Re: how to keep my feet warm!
« on: February 02, 2014, 11:19:22 am »
Start taking niacin that is niacin not niacinamide. Start small around 100mg to see what you can tolerate. It will clear out your arteries but it takes time expect a year before you notice. Every ones arteries are clogged autopsies on fetuses routinely find plaque buildup. In an emergency situation that is extreme cold or a downpour you can wrap your feet in plastic shopping bags this will prevent moisture from escaping so you will need to dry and wash as soon as possible. If you are expecting  frostbite carefully notice which parts of your toes get the coldest and put on some triple antibiotic either Neosporin or a generic. The petroleum in these is an insulator and petroleum jelly is used by extreme cold water swimmers. Don't overdo this or you could end up with drug resistant bacteria.

74
Gear Talk / Re: Camping Gas/stove
« on: January 04, 2014, 03:17:46 pm »
Airlines are not going to allow you to transport a stove back home. You will need to abandon it. So the cheapest option under these condition is a propane stove. The stove can be had for $10 and the fuel canisters are $2. The canisters made for torches will also fit the stove. Propane is around 2 to 4 times as expensive as gasoline. It has the advantage of starting in much colder temps gasoline has problems at 0 centigrade. http://www.youtube.com/watch?v=bmjd_6WgkTE

75
Gear Talk / Re: best touring frames
« on: December 21, 2013, 08:15:00 am »
I'm riding a mongoose with all 4130 steel frame. Every steel frame made today is less stiff and this includes the Comotion ones made with tandem tubing. The only frame I would consider today is the REI Safari and even then I would have to go to the show room and make sure it is the one with the 1.5 inch down tube and not the one with the 1.375 inch down tube.

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