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InterBike
More disappointing than last year with more fashion than in the past
and no new products pr solution. I found not a single rim that had sockets and eyelets and the shop owners who stopped to look complained they get a lot of cracked rims. To make up for that a CVT using tilt-ball friction drive tried to convince me that I was wrong about the not being such a device that is continuous while using positive engagement gears. When I saw how it worked, I pointed out that many machine tools were run that way and that their hub was horrendously heavy. I am surprised that they received 30+ patents on this ancient drive mechanism that Leonardo sketched centuries ago: http://cocolico.info/design/nuvinci-fallbrook-bike There were no tire patches and few tire pumps but rather CO2 cartridges. Large billboards had photos of macho-men grimacing jut jawed with three day stubble on their faces. I mentioned that I see enough of these poseurs who are so busy with their schtick that they cannot respond to a greeting from a bicyclist going the other way. The best design I saw was the STRIDA commute /folding bicycle: http://www.strida.us/ I was saddened to see that Switzerland had lost their logo, something I always found endearing, being a fan to the great William Tell who stands in Canto Uri bigger than life with crossbow over his right shoulder and his small son on his left. http://www.tell.ch/schweiz/telldenkmal.htm All articles made in Switzerland had a small crossbow that was far more elegant than "Swiss Made" or "Made in Switzerland"": http://www.swisslabel.ch/d/ No Swiss product carries that logo anymore3 and DT SWISS spokes said the feds had tightened down on use of national emblems in business. Jobst Brandt |
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#2
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InterBike
wrote:
More disappointing than last year with more fashion than in the past and no new products pr solution. I found not a single rim that had sockets and eyelets and the shop owners who stopped to look complained they get a lot of cracked rims. eh? 1. dt swiss and mavic and ambrosio and [insert a number of other names] still make socketed rims jobst. you're just not looking. or [more likely] you're only seeing what you want to see. besides, there's not much point in a socketed rim - the web on which the socket sits is so thin, it offers negligible structural benefit. http://www.flickr.com/photos/38636024@N00/121453841/ you may as well take the weight savings and call it a day. which is of course what manufacturers with the time and money to do their homework frequently do. 2. shop owners who crack rims are those poor souls that /you/ have duped with your underinformed drivel about spoke tension "as high as the rim can bear" jobst. misconstruing a load calculation as a strength calculation was a gross mistake on your part and has cost a lot of people a lot of money. the very least you can do is make the effort to correct yourself - especially now as the facts have been pointed out for you. apologizing might help too, although it will not compensate them anywhere near appropriately. remaining incoherent bleatings snipped - you appear to be losing your thread jobst... |
#3
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InterBike
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#4
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InterBike
jim beam wrote:
*besides, there's not much point in a socketed rim - the web on which the socket sits is so thin, it offers negligible structural benefit. http://www.flickr.com/photos/38636024@N00/121453841/ There looks to be plenty of structural benefit there-- especially since the perimeter of the socket that sits on the outward-facing wall of the rim is so much larger and closer to the rim sidewalls than the part that sits on the spoke bed. On top of that, it keeps nipples from going astray during building and diminishes the likelihood of drilled holes cutting the rim strip. Chalo |
#5
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InterBike
Chalo wrote:
jim beam wrote: �besides, there's not much point in a socketed rim - the web on which the socket sits is so thin, it offers negligible structural benefit. http://www.flickr.com/photos/38636024@N00/121453841/ There looks to be plenty of structural benefit there-- especially since the perimeter of the socket that sits on the outward-facing wall of the rim is so much larger and closer to the rim sidewalls than the part that sits on the spoke bed. that web is so thin, if it supported the full cyclic 1000N spoke load, it wouldn't last 100 miles. On top of that, it keeps nipples from going astray during building that's true. not worth the weight penalty just for that though. besides, if sockets are such a structural benefit, why don't mtb rims have them? [rhetorical] none do as far as i know. but there's no complaining because they're not ridden by crusty misguided old farts in palo alto. and diminishes the likelihood of drilled holes cutting the rim strip. in my experience, rusted sockets are much more successful at cutting rim strips! |
#6
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InterBike
jim beam wrote:
that web is so thin, if it supported the full cyclic 1000N spoke load, it wouldn't last 100 miles. But it doesn't have to support the whole spoke tension. Any one turn of a fastener's thread does not have to support the entire fastener tension, and it's better to have several turns bearing the load. I don't see why the same advantages don't confer to the rim that bears spoke tension loads on both walls instead of only one. besides, if sockets are such a structural benefit, why don't mtb rims have them? *[rhetorical] *none do as far as i know. * Mavic M261 and M281 had them. The Alex Supra RX, a BMX rim, has them. MTB rims have it easier in some regards than road bike rims. They are larger in section and smaller in hoop diameter, and riding stresses are more evenly distributed by the fat tire. I'd not be at all surprised if fluctuations in spoke tension were greater in skinny-tire wheels even if the overall duty of the bike is lighter. Chalo |
#7
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InterBike
jim beam wrote:
besides, if sockets are such a structural benefit, why don't mtb rims have them? *[rhetorical] *none do as far as i know. * http://www.mavic.com/mtb/products/ex....995014.2.aspx Chalo |
#8
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InterBike
Chalo wrote:
MTB rims have it easier in some regards than road bike rims. They are larger in section and smaller in hoop diameter, and riding stresses are more evenly distributed by the fat tire. I'd not be at all surprised if fluctuations in spoke tension were greater in skinny-tire wheels even if the overall duty of the bike is lighter. This is very true. Road rims are much more difficult to engineer because the stress is not well distributed. As far as Interbike, remember that most companies bring only a small subset of their products to the show. No doubt many of the rim manufacturers showing their "stupid-light" rims, do have more practical products with sockets and eyelets to make the rims more reliable. Apparently many enthusiasts walk into a bike shop with a small scale and a credit card with a high limit. These are very profitable customers for shops, and these customers help subsidize the operation of the less profitable goods and services the shop offers. It's like the car buyers that walk into a car dealer and happily pay "invoice" or MSRP, then add an extended warranty, pin striping, undercoating, fabric guard, glass etching, paint protectant, etc., giving the dealer enough profit to allow them to sell the same vehicle to other customers for well under invoice. |
#9
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InterBike
Chalo wrote:
jim beam wrote: that web is so thin, if it supported the full cyclic 1000N spoke load, it wouldn't last 100 miles. But it doesn't have to support the whole spoke tension. but it doesn't have to support /any/ if there's no socket! look at all the rims that have no socket, and which, when built with manufacturers spoke spec, are perfectly reliable. look at how thin and insubstantial that web is. because of dimensions, simple elasticity dictates that the maximum load it bears is 1/3rd of that of the main rim bed... Any one turn of a fastener's thread does not have to support the entire fastener tension, and it's better to have several turns bearing the load. only three threads bear a load - unless it's taper thread. I don't see why the same advantages don't confer to the rim that bears spoke tension loads on both walls instead of only one. besides, if sockets are such a structural benefit, why don't mtb rims have them? �[rhetorical] �none do as far as i know. � Mavic M261 and M281 had them. The Alex Supra RX, a BMX rim, has them. MTB rims have it easier in some regards than road bike rims. absolutely not. not when used for their intended application at any rate. They are larger in section and smaller in hoop diameter, and riding stresses are more evenly distributed by the fat tire. smaller diameter, yes. fat tire load distribution??? absolutely not. I'd not be at all surprised if fluctuations in spoke tension were greater in skinny-tire wheels even if the overall duty of the bike is lighter. absolutely not if the mtb is actually ridden mtb. the only advantage i see that mtb rims have is the slightly better dish of the rear wheel - more even spoke tension. and maybe smaller diameter. other than that, at least in my experience, mtb rims have a significantly tougher life than any road rim. Chalo |
#10
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InterBike
SMS wrote:
Chalo wrote: MTB rims have it easier in some regards than road bike rims. They are larger in section and smaller in hoop diameter, and riding stresses are more evenly distributed by the fat tire. I'd not be at all surprised if fluctuations in spoke tension were greater in skinny-tire wheels even if the overall duty of the bike is lighter. This is very true. Road rims are much more difficult to engineer because the stress is not well distributed. eh? you've never ridden mtb obviously. As far as Interbike, remember that most companies bring only a small subset of their products to the show. No doubt many of the rim manufacturers showing their "stupid-light" rims, do have more practical products with sockets and eyelets to make the rims more reliable. Apparently many enthusiasts walk into a bike shop with a small scale and a credit card with a high limit. These are very profitable customers for shops, and these customers help subsidize the operation of the less profitable goods and services the shop offers. It's like the car buyers that walk into a car dealer and happily pay "invoice" or MSRP, then add an extended warranty, pin striping, undercoating, fabric guard, glass etching, paint protectant, etc., giving the dealer enough profit to allow them to sell the same vehicle to other customers for well under invoice. |
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