|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
35 30 26 22 19 16 14 12 Cassette
Hello rbt!
For an unsolicited proposal to the US Army for a recumbent bicycle for our troops, I need to first verify that the SRAM 3x8 hub ratio is 0.72:1:1.36 and get that as an exact fraction (the planetary gearing formula with tooth counts). Assuming that is the right ratio, the title cassette is optimum for the application. Is such a cassette possible? Is a rear derailer available that will shift it, assuming the mounting stud can be located anywhere in an OEM situation, not at a given point as is standard? If not available, I have an alternative cassette and will post it. Non-Hyperglide is fine. I have heard of a 36 T cog. I do know Hyperglide only goes to 34 T, and also works best in preselected combinations, none of which suit the application, which is an evenly spaced cassette and hub, double step, wide range transmission. Each cassette step is half a hub step. Each hub step is two cassette steps, to within 5% logarithm of gear ratio scaled to gear numbers 1-24. The alternative cassette is evenly spaced to within 7%. Actually 4.8% for this cassette and 7.1% for the alternative. That two percentage difference matters. The proposal must be solid, making full use of existing manufacturing capability. Stock parts are for model vehicles. But let's start with the SRAM 3x8 hub. Do any of you know its tooth counts or do I have to tear down my brother's hub and count them myself? Yours, Doug Goncz ( ftp://users.aol.com/DGoncz/incoming ) Student member SAE for one year. I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. |
Ads |
#2
|
|||
|
|||
On 26 Sep 2004 12:25:13 GMT, ( Doug Goncz ) wrote:
For an unsolicited proposal to the US Army for a recumbent bicycle for our troops, Funny. JT **************************** Remove "remove" to reply Visit http://www.jt10000.com **************************** |
#3
|
|||
|
|||
From: John Forrest Tomlinson
References: On 26 Sep 2004 12:25:13 GMT, ( Doug Goncz ) wrote: For an unsolicited proposal to the US Army for a recumbent bicycle for our troops, Funny. Objective Force Warrior. Not funny. Yours, Doug Goncz ( ftp://users.aol.com/DGoncz/incoming ) Student member SAE for one year. I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. |
#4
|
|||
|
|||
Doug Goncz Wrote: Hello rbt! For an unsolicited proposal to the US Army for a recumbent bicycle fo our troops, I need to first verify that the SRAM 3x8 hub ratio is 0.72:1:1.36 and get that as an exact fraction (the planetary gearing formula with tooth counts). Assuming that is the right ratio, the title cassette is optimum for the application. Is such a cassette possible? Is a rear derailer available that will shift it, assuming the mountin stud can be located anywhere in an OEM situation, not at a given point as i standard? If not available, I have an alternative cassette and will post it. Non-Hyperglide is fine. I have heard of a 36 T cog. I do kno Hyperglide only goes to 34 T, and also works best in preselected combinations, none o which suit the application, which is an evenly spaced cassette and hub double step, wide range transmission. Each cassette step is half a hub step. Eac hub step is two cassette steps, to within 5% logarithm of gear ratio scaled t gear numbers 1-24. The alternative cassette is evenly spaced to within 7%. Actually 4.8 for this cassette and 7.1% for the alternative. That two percentage difference matters. The proposal must be solid making full use of existing manufacturing capability. Stock parts are for mode vehicles. But let's start with the SRAM 3x8 hub. Do any of you know its toot counts or do I have to tear down my brother's hub and count them myself? Yours, Doug Goncz ( ftp://users.aol.com/DGoncz/incoming ) Student member SAE for one year. I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. Most rders speced for 34T should handle 35, but 35T unlike 34T woul likely require a more expensive a custom made sprocket or somethin like a Spicer cassette chainring adapter which is more expensive tha the custom cassette. The even ratiometric spacing fails to consider the exponential effec of speed on aerodynamic drag. The higher speed gears should be close together. The off pavement attributes of a recumbent make it a poor choice fo combat use. The Montague folding mountain bike which has been deployed t paratroopers is the appropriate choice for combat troops, or bik something similar in function -- meb |
#5
|
|||
|
|||
From: meb
The Montague folding mountain bike which has been deployed to paratroopers is the appropriate choice for combat troops, or bike something similar in function. Hey, I'm not married to the idea. The current development platform is recumbent. The previous was a Peugot mountain bike and is still available. Ugh. Not awake yet. You have my sincere thanks for letting me know about the Spicer adapter. Yours, Doug Goncz ( ftp://users.aol.com/DGoncz/incoming ) Student member SAE for one year. I love: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. |
#6
|
|||
|
|||
meb wrote in message
[...] The off pavement attributes of a recumbent make it a poor choice for combat use. [...] Some army bases are huge places with serious restrictions on car traffic. Maybe this is for human transport on military facilities? A bicycle in combat would quite hilarious. |
#7
|
|||
|
|||
Someone wrote:
[...] The off pavement attributes of a recumbent make it a poor choice for combat use. Someone else replied: A bicycle in combat would quite hilarious. Actually, bicycles have had significant military uses in a number of wars. Late 19th century writers liked to picture bicycle-mounted cavalry charges, but the contemporary development of machine guns and barbed wire made all cavalry charges obsolete. However, the bicycle as a combat transport vehicle has been used quite successfully, especially in southeast asia. The Japanese used bicycle-mobile troops to out the British during their conquest of Malaya. The Vietnamese used bicycles extensively to drive out first the French, and later the Americans. In particular, the decisive battle of Dien Bien Phu was won by Vietnamese forces transporting dis-assembled artillery through supposedly impassable jungle terrain to command the heights of the main French air base in northern Vietnam. In the war agains the U.S., the famous "Ho Chi Minh" trail was actually a bicycle route. The Vietnamese could transport up to 600 pounds of materiel using bikes in a sort of wheelbarrow mode, then ride them back up north for another load. See: Martin Caidin "Bicycles in War" Sheldon "Not That Hilarious" Brown +-------------------------------------------------------------+ | Want of care does us more damage than want of knowledge. | | -- Benjamin Franklin | +-------------------------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide http://captainbike.com http://sheldonbrown.com |
#8
|
|||
|
|||
In article ,
Sheldon Brown wrote: Someone wrote: [...] The off pavement attributes of a recumbent make it a poor choice for combat use. Someone else replied: A bicycle in combat would quite hilarious. Actually, bicycles have had significant militarytop uses in a number of wars. To add a bit, I have a photo of my Grandfather in WWII posing with his bicycle. Apparently they used them to move around because motorized vehicles weren't always available and there were often obstacles that would stop a heavier vehicle, but a bike could be carried across. [...] -- B.B. --I am not a goat! thegoat4 at airmail.net |
#9
|
|||
|
|||
-----BEGIN PGP SIGNED MESSAGE-----
In article , Sheldon Brown wrote: Someone wrote: [...] The off pavement attributes of a recumbent make it a poor choice for combat use. Someone else replied: A bicycle in combat would quite hilarious. Actually, bicycles have had significant military uses in a number of wars. Late 19th century writers liked to picture bicycle-mounted cavalry charges, but the contemporary development of machine guns and barbed wire made all cavalry charges obsolete. However, the bicycle as a combat transport vehicle has been used quite successfully, especially in southeast asia. _ Check out the Iron Riders.... http://www.ltolman.org/99arch/01819ironriders.htm _ Booker C. Bense -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBQVhQM2TWTAjn5N/lAQH/pAP+MyHs7yet8QdOKpONJpfpD84nySLFRB1k 66iyf30e3xYcYV55ZPsv7el3JrG53Vqv7dUDCImn1k9FMbC+25 Di+HjhmjrteFK+ 7lFv5OY+yUNPBYzdNiHjv++N/HZhamRocMhLaofqkZLN88ks/pc6GEXK77lkbrO6 HrhrcEmP7sA= =G6Es -----END PGP SIGNATURE----- |
#10
|
|||
|
|||
"B.B." u wrote in message news In article , Sheldon Brown wrote: Someone wrote: [...] The off pavement attributes of a recumbent make it a poor choice for combat use. Someone else replied: A bicycle in combat would quite hilarious. Actually, bicycles have had significant militarytop uses in a number of wars. To add a bit, I have a photo of my Grandfather in WWII posing with his bicycle. Apparently they used them to move around because motorized vehicles weren't always available and there were often obstacles that would stop a heavier vehicle, but a bike could be carried across. B.B. --I am not a goat! thegoat4 at airmail.net Working in Cambodia in the repatriation operation in the early 90's, we had white Landcruisers (bloody UN), Honda CL125 motorbikes and privately bought mountain bikes. Of the three, the mountain bikes were the most useful - one broken bridge would stop both the 4WD and the motorbike. I still have good memories of the governor of Banteay Meanchey province riding out with me to a meeting with a (friendly) Khmer Rouge group on our bicycles. As he was an important man, his guard sat on the back with his AK47 while the governor pedalled. Hugh Fenton (Now in much more boring Belgrade) |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Will 11-32 Cassette Fit On 9 Sp Cannondale Expert Hub | Dave Thompson | Techniques | 5 | July 1st 04 10:48 AM |
STX Derailleur on 9 speed cassette | Brad Kattelmann | Techniques | 8 | March 27th 04 12:48 AM |
Cross threaded Cassette Fix?? | Dirk Diggler | Techniques | 5 | November 3rd 03 12:34 AM |
Question: Cassette Sizing | Michael | General | 6 | August 6th 03 01:48 PM |