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#21
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 6, 11:21*am, Jobst Brandt wrote:
Ed who? wrote: I am considering rebuilding a set of wheels that had Alex 20/24 hole rims. *They went about 5K miles before the spokes started to pull thorough the rims. I am considering using these hubs and Velocity Aerohead and Aerohead O/C rims but am wondering about the durability because of my previous experience with the Alex rims. I currently have a set of these Velocity rims but in 32 hole configuration that have been flawless for the past 10K miles. BTW, I only weigh about 160 pounds. As I understand it you have a set of hubs you would like to re rim and you would like your work to last more than 5000 miles. A key point is: suddenly applied loads double the stress on any structure when compared to statically applied loads. In your experience 32 hole rims last at least twice as long as 20/24 hole rims and the weak point appears to be the rim (where some rims have an eyelet). I am not convinced an eyelet is going to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. If I were trying to get more miles out of those hubs - or specifically rims attached to those hubs - I would select a rim that could be run at the lowest pressure possible (consistent with Josh above). *That would mean tubeless at 80 lbs. *I am told the A23 was designed to be convertered and I know that Stan's Alpha rims were designed to be run tubeless. A key point is I've been told the spoke that is supporting the weight is the spoke in tension immediately above the hub. *All the other spokes are keeping the wheel round as the top of the rim tries to deform inward. *The more the top of the rim can deform inward the more the load on the spoke above the hub is reduced. *Long story short: a shallow section like the A23 should reduce the peak loads on the eyelet area and tubeless at low pressures should reduce the suddeness of the load effectively reducing the peak stress on the eyelet area. You have been misled (pronounced my-seld) again. *The load is carried by compressing the bottom spokes between hub and road. *If they are too loose and become slack from loading, the spoke nipples unscrew or worse, the wheel collapses, having no lateral rim position for lack of spoke pull to the sides. Use the A23 tubeless if you want ot stick with those hubs. What does "tubeless" have to do with cracking rims? Jobst Brandt- Hide quoted text - - Show quoted text - Tubeless allows lower tire pressures which means less sudden loading conditions and a larger contact patch. The larger contact patch un loads the rim over a larger area (this is based on the free body digram of all road to rim loads being imposed by tire forces at the bead.). The smeared unloading should reduce the peak cyclic load on the part of the rim that holds the nipple. The part that cracks. |
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#22
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Thu, 04 Nov 2010 19:37:31 -0400, Steve Sr.
wrote: Hello, I am considering rebuilding a set of wheels that had Alex 20/24 hole rims. They went about 5K miles before the spokes started to pull thorough the rims. I am considering using these hubs and Velocity Aerohead and Aerohead O/C rims but am wondering about the durability because of my previous experience with the Alex rims. I currently have a set of these Velocity rims but in 32 hole configuration that have been flawless for the past 10K miles. BTW, I only weigh about 160 pounds. Thanks, Steve Thanks for everyones input. I agree with Andrew that the spoke count is on low side for durability. As I mentioned, the original rims started to fail at about 5K miles and were replaced under warranty. The new set had about 5K miles on them when a minor crash took out the front wheel. Since I have 5K on the rear which is where the original failed I was planning on rebuilding both to be done with it. Were these over tensioned? I have no way of knowing. I am primarily looking at rebuilding these as a secondary/spare set and not wanting to break the bank doing it. This includes reusing the spokes if at all possible. This is one reason why I was looking at the Aerohead. I believe that the ERD was close enough to use the old spokes. The hubs are radial in the front and radial/3 cross in the rear if that matters. Steve |
#23
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
Ed wrote:
I am not convinced an eyelet is goint to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. A single eyelet (grommet) serves two valuable purposes: It provides a better bearing surface for the spoke nipple head, and it helps prevent galling damage at the drilling from initiating cracks into the rim extrusion. Double eyelets (sockets) are still offered by Mavic, Rigida, and Alex on a few models. Whether they actually transfer any load to the internal wall of the rim depends on the specifics of the socket and the rim extrusion and manufacturing tolerances. On modern deep and semi-deep section rims, sockets offer the benefit of keeping nipples from going astray within the rim channel while the wheel is being laced. Chalo |
#24
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
Steve Sr. wrote:
On Thu, 04 Nov 2010 19:37:31 -0400, Steve Sr. wrote: Hello, I am considering rebuilding a set of wheels that had Alex 20/24 hole rims. They went about 5K miles before the spokes started to pull thorough the rims. I am considering using these hubs and Velocity Aerohead and Aerohead O/C rims but am wondering about the durability because of my previous experience with the Alex rims. I currently have a set of these Velocity rims but in 32 hole configuration that have been flawless for the past 10K miles. BTW, I only weigh about 160 pounds. Thanks, Steve Thanks for everyones input. I agree with Andrew that the spoke count is on low side for durability. As I mentioned, the original rims started to fail at about 5K miles and were replaced under warranty. The new set had about 5K miles on them when a minor crash took out the front wheel. Since I have 5K on the rear which is where the original failed I was planning on rebuilding both to be done with it. Were these over tensioned? I have no way of knowing. I am primarily looking at rebuilding these as a secondary/spare set and not wanting to break the bank doing it. This includes reusing the spokes if at all possible. This is one reason why I was looking at the Aerohead. I believe that the ERD was close enough to use the old spokes. The hubs are radial in the front and radial/3 cross in the rear if that matters. Steve Another path is to give those hubs away and get a set of 36h Shimano hubs. Hubs are an area in which Shimano shines, dirt cheap and very tough. Rims cost the same in any drill. You'd also have the opportunity to build 3x front and rear. Bonus. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#25
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 6, 2:04*pm, Chalo wrote:
Ed wrote: I am not convinced an eyelet is goint to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. A single eyelet (grommet) serves two valuable purposes: *It provides a better bearing surface for the spoke nipple head, and it helps prevent galling damage at the drilling from initiating cracks into the rim extrusion. Double eyelets (sockets) are still offered by Mavic, Rigida, and Alex on a few models. *Whether they actually transfer any load to the internal wall of the rim depends on the specifics of the socket and the rim extrusion and manufacturing tolerances. *On modern deep and semi-deep section rims, sockets offer the benefit of keeping nipples from going astray within the rim channel while the wheel is being laced. Alex R390s have been nothing but rock solid in my experience. Not too light or too heavy, much like a CR18 in that regard. Socketed and cheap. If they hold up to my buddy Shep, they'll pretty much stand up to most folks. |
#26
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
landotter wrote:
On Nov 6, 2:04 pm, Chalo wrote: Ed wrote: I am not convinced an eyelet is goint to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. A single eyelet (grommet) serves two valuable purposes: It provides a better bearing surface for the spoke nipple head, and it helps prevent galling damage at the drilling from initiating cracks into the rim extrusion. Double eyelets (sockets) are still offered by Mavic, Rigida, and Alex on a few models. Whether they actually transfer any load to the internal wall of the rim depends on the specifics of the socket and the rim extrusion and manufacturing tolerances. On modern deep and semi-deep section rims, sockets offer the benefit of keeping nipples from going astray within the rim channel while the wheel is being laced. Alex R390s have been nothing but rock solid in my experience. Not too light or too heavy, much like a CR18 in that regard. Socketed and cheap. If they hold up to my buddy Shep, they'll pretty much stand up to most folks. At 485g I'd expect so: http://www.alexrims.com/product_deta...=1&cat=1&id=44 -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#27
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 6, 2:50*pm, AMuzi wrote:
landotter wrote: On Nov 6, 2:04 pm, Chalo wrote: Ed wrote: I am not convinced an eyelet is goint to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. A single eyelet (grommet) serves two valuable purposes: *It provides a better bearing surface for the spoke nipple head, and it helps prevent galling damage at the drilling from initiating cracks into the rim extrusion. Double eyelets (sockets) are still offered by Mavic, Rigida, and Alex on a few models. *Whether they actually transfer any load to the internal wall of the rim depends on the specifics of the socket and the rim extrusion and manufacturing tolerances. *On modern deep and semi-deep section rims, sockets offer the benefit of keeping nipples from going astray within the rim channel while the wheel is being laced. Alex R390s have been nothing but rock solid in my experience. Not too light or too heavy, much like a CR18 in that regard. Socketed and cheap. If they hold up to my buddy Shep, they'll pretty much stand up to most folks. At 485g I'd expect so:http://www.alexrims.com/product_deta...=1&cat=1&id=44 Probably more like 500g on a real scale. A proper amount of metal for real world use. The Adventurers I built up scaled at something like 650g. With 900g 47mm Continentals. The trick is to stay at speed. ;-) And ride with slow clydes. |
#28
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 6, 12:53*pm, Steve Sr. wrote:
The hubs *are radial in the front and radial/3 cross in the rear if that matters. 24H, 3x? Does not seem likely. DR |
#29
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 6, 1:06*pm, landotter wrote:
On Nov 6, 2:50*pm, AMuzi wrote: landotter wrote: On Nov 6, 2:04 pm, Chalo wrote: Ed wrote: I am not convinced an eyelet is goint to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. A single eyelet (grommet) serves two valuable purposes: *It provides a better bearing surface for the spoke nipple head, and it helps prevent galling damage at the drilling from initiating cracks into the rim extrusion. Double eyelets (sockets) are still offered by Mavic, Rigida, and Alex on a few models. *Whether they actually transfer any load to the internal wall of the rim depends on the specifics of the socket and the rim extrusion and manufacturing tolerances. *On modern deep and semi-deep section rims, sockets offer the benefit of keeping nipples from going astray within the rim channel while the wheel is being laced. Alex R390s have been nothing but rock solid in my experience. Not too light or too heavy, much like a CR18 in that regard. Socketed and cheap. If they hold up to my buddy Shep, they'll pretty much stand up to most folks. At 485g I'd expect so:http://www.alexrims.com/product_deta...=1&cat=1&id=44 Probably more like 500g on a real scale. A proper amount of metal for real world use. The Adventurers I built up scaled at something like 650g. With 900g 47mm Continentals. The trick is to stay at speed. ;-) And ride with slow clydes.- Hide quoted text - The R390 web-page claims that it is a racing and tri rim, 500g seems pretty heavy for a racing rim. -- Jay Beattie. |
#30
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Durability Of Velocity Aerohead Rims In 20/24 Hole Drillings.
On Nov 6, 6:19*pm, Jay Beattie wrote:
On Nov 6, 1:06*pm, landotter wrote: On Nov 6, 2:50*pm, AMuzi wrote: landotter wrote: On Nov 6, 2:04 pm, Chalo wrote: Ed wrote: I am not convinced an eyelet is goint to solve things unless you get one that transfers the force to the inner wall of the rim - I don't think they make those any more. A single eyelet (grommet) serves two valuable purposes: *It provides a better bearing surface for the spoke nipple head, and it helps prevent galling damage at the drilling from initiating cracks into the rim extrusion. Double eyelets (sockets) are still offered by Mavic, Rigida, and Alex on a few models. *Whether they actually transfer any load to the internal wall of the rim depends on the specifics of the socket and the rim extrusion and manufacturing tolerances. *On modern deep and semi-deep section rims, sockets offer the benefit of keeping nipples from going astray within the rim channel while the wheel is being laced. Alex R390s have been nothing but rock solid in my experience. Not too light or too heavy, much like a CR18 in that regard. Socketed and cheap. If they hold up to my buddy Shep, they'll pretty much stand up to most folks. At 485g I'd expect so:http://www.alexrims.com/product_deta...=1&cat=1&id=44 Probably more like 500g on a real scale. A proper amount of metal for real world use. The Adventurers I built up scaled at something like 650g. With 900g 47mm Continentals. The trick is to stay at speed. ;-) And ride with slow clydes.- Hide quoted text - The R390 web-page claims that it is a racing and tri rim, 500g seems pretty heavy for a racing rim. -- Jay Beattie. Certainly. However, it's a damn good rim for non-racing roadies who want durability. I do have a feeling that it probably wouldn't slow any champs down compared to an OP. |
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