|
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
WHy no red tires on cars - only antique bikes?*
On Feb 7, 4:35*am, wrote:
Dear Martin, The best rubber for early bicycles (highwheelers) was considered to be Para rubber (from the Para rubber-tree region of Brazil, as opposed to African and other sources). The red color came from the compounds (kmostly antimony) that made the natural rubber harder and stronger and longer-wearing, but not so stretchy. Gray rubber tires were considered inferior, even though they might use the same Para rubber. Gray rubber was stretchy and wore quickly and failed more easily because it was mostly natural rubber, plus the minimum amount of sulphur needed for vulcanizing. Gray rubber simply lacked the compounds that turned natural Para rubber into better stuff. This passage about the gray and red rubber used in inner tubes explains the basic idea: "To effect proper vulcanization, only about three per cent of sulphur is needed. Tubes which are made of red rubber, while stronger, are not so elastic as as those made of gray rubber. The red color is given to rubber chiefly by the use of metallic oxids, chiefly antimony. When so treated, the elongation is about five times its length when not more than fifty per cent of oxids are used. Gray rubber, which is free from adulteration, except the necessary sulphur, should stretch to seven times its length." Thank you, Carl, for clearing that up. I was thinking of this again this morning as the sun came up like a red rubber ball. (And you're correct about Google Books and Canadian - or possibly all Non-USA-based ISPs) being blocked from the actual contents.) |
Ads |
#12
|
|||
|
|||
WHy no red tires on cars - only antique bikes?*
On Feb 7, 1:59*pm, Martin Krieg wrote:
THX for taking the time to do research for this!! I am going to post it at the Wheelmen sitehttp://thewheelmen.org/forum/default.asp*where I have also posed this question. * *THX 4 U! In article , wrote: Dear Martin, The best rubber for early bicycles (highwheelers) was considered to be Para rubber (from the Para rubber-tree region of Brazil, as opposed to African and other sources). The red color came from the compounds (kmostly antimony) that made the natural rubber harder and stronger and longer-wearing, but not so stretchy. Gray rubber tires were considered inferior, even though they might use the same Para rubber. Gray rubber was stretchy and wore quickly and failed more easily because it was mostly natural rubber, plus the minimum amount of sulphur needed for vulcanizing. Gray rubber simply lacked the compounds that turned natural Para rubber into better stuff. This passage about the gray and red rubber used in inner tubes explains the basic idea: "To effect proper vulcanization, only about three per cent of sulphur is needed. Tubes which are made of red rubber, while stronger, are not so elastic as as those made of gray rubber. The red color is given to rubber chiefly by the use of metallic oxids, chiefly antimony. When so treated, the elongation is about five times its length when not more than fifty per cent of oxids are used. Gray rubber, which is free from adulteration, except the necessary sulphur, should stretch to seven times its length." *http://books.google.com/books?id=HKI...frontcover#PPA... orhttp://tinyurl.com/32q5cr Canandian posters may have limited or no access to Google books. Elsewhere, the book gives examples of gray stretchy inner tubes being made of 94% natural Para rubber and 6% sulphur (hardly any compounds), while red inner tubes, longer lasting, were only about 75% rubber and 25% antimony, magnesia, and so on (four times as much non-rubber compound). Tires were harder and used even less rubber than inner tubes, but the same principles held. Red rubber meant lots of antimony and other stuff to improve the soft, too-stretchy natural rubber, while gray rubber meant the bare minimum of improving chemicals. Improvements in technology led to the use of carbon black to make the natural rubber last longer and still provide good traction, followed by the rise of synthetic rubber. Here's an example of an 1887 highwheeler ad that boasts of tires made of the "very best quality red Para rubber", as opposed to the inferior gray stuff: *http://www.tallbike.com/tall/87rudge.html Note that the huge online book about tires is discussing early car tires and inner tubes. Cheers, Carl Fogel Dear Martin, Everything that you ever wanted to know about making rubber bicycle tires, in popular form: http://books.google.com/books?id=rZD...#PRA1-PA381,M1 or http://tinyurl.com/yqmmt7 Alas, the McClure's magazine pages can be beastly slow to load and may not be available to non-U.S. posters. The article is from McClure's Magazine volume 8, 1896-1897 November- April, page 381, "A Visit to the Hartford Rubber Works," Cleveland Moffett. Cheers, Carl Fogel |
#13
|
|||
|
|||
WHy no red tires on cars - only antique bikes?*
On Feb 7, 1:59*pm, Martin Krieg wrote:
THX for taking the time to do research for this!! I am going to post it at the Wheelmen sitehttp://thewheelmen.org/forum/default.asp*where I have also posed this question. * *THX 4 U! Dear Martin, Here's a really short, clear explanation, from the English Mechanic of 1878: "Get the best quality rubber. The grey is in reality the purer of the two [red and grey], but the red is rather more durable on account of a mixture of a hardening nature, sulphur being the principal ingredient. Therefore, have the red, or, as it is called, 'indestructible'." "The weight will be about 4 lb. The better the rubber, the lighter-- consequently, there is not much gained by buying the lower quality." http://books.google.com/books?id=Unk...rr=0#PPA144,M1 Actually, both grey and red rubber used sulphur for vulcanizing, and the red color and durability was from antimony and other added ingredients, but the advice was basically good. Cheers, Carl Fogel |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Bikes outsell cars in Oz | vey | Techniques | 1 | January 8th 08 04:23 AM |
bikes on cars on trains | davek | UK | 20 | May 5th 05 01:10 PM |
"cars more fun than bikes" | Fritz M | General | 0 | January 11th 05 11:08 PM |
hybrid cars and bikes | Rob F. in Houston | General | 51 | January 2nd 04 01:27 AM |
Bikes & Cars - The MixingThread | Just zis Guy, you know? | Social Issues | 1 | December 10th 03 09:04 PM |