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Date: 17 Oct 2007 11:47:53
From: Donald Gillies
Subject: Re: rim recommendations?
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"James Thomson" <yosnappyj@hotmail.com > writes:
>"Ben C" <spamspam@spam.eggs> a ecrit:
>> I know, and I couldn't see any stickers in the pictures either. They do
>> look very "low-profile"-- a similar sort of depth to MA-2s rather than
>> the deeper U-shape of an Open Pro.
>O'Grady was riding Ambrosio rims during the race, probably their "Nemesis"
>model. You can see the telltale gold-coloured balance weights in this
>picture:
>http://www.cervelo.com/wallpaper/1/w037_2560ws.jpg
>http://www.ambrosiospa.com/catalog_eng/
I thought that a tire valve is even heavier than the rim's pin that
holds it together (and, these are retro pinned tubular rims ??) Is
the pin THAT HEAVY inside of a 420 gram tubular rim that it needs
extra weight ??
- Don Gillies
San Diego, CA, USA
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Date: 18 Oct 2007 00:23:42
From: James Thomson
Subject: Re: rim recommendations?
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"Donald Gillies" <gillies@cs.ubc.ca > a écrit:
> I thought that a tire valve is even heavier than the rim's
> pin that holds it together
It may well be. I didn't say the idea had merit.
> (and, these are retro pinned tubular rims ??)
I don't know, but I do know that some modern welded and machined rims still
use an internal pin to hold the joint in alignment.
James Thomson
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Date: 17 Oct 2007 21:22:07
From: jim beam
Subject: Re: rim recommendations?
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James Thomson wrote:
> "Donald Gillies" <gillies@cs.ubc.ca> a �crit:
>
>> I thought that a tire valve is even heavier than the rim's
>> pin that holds it together
>
> It may well be. I didn't say the idea had merit.
>
>> (and, these are retro pinned tubular rims ??)
>
> I don't know, but I do know that some modern welded and machined rims still
> use an internal pin to hold the joint in alignment.
>
> James Thomson
>
>
it's not to hold the joint as such, it's to keep the internal welding
flash in place and to give the electrode pinch contacts somewhere to
bite as they contact-weld the rim ends.
http://www.flickr.com/photos/38636024@N00/275085692/
those are two separate plug pieces, not one.
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Date: 18 Oct 2007 16:45:55
From: Donald Gillies
Subject: Re: rim recommendations?
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jim beam <spamvortex@bad.example.net > writes:
>[the pin is] not to hold the joint as such, it's to keep the internal
>welding flash in place and to give the electrode pinch contacts
>somewhere to bite as they contact-weld the rim ends.
>http://www.flickr.com/photos/38636024@N00/275085692/
>those are two separate plug pieces, not one.
I liked the old pinned rims, they had pins kinda like the red plastic
strips the held my hot-wheel cars together. The pins would be showing
until you tightened up the spokes enough to cause the ends of the rim
to collapse inwards and hide the flat pins.
those were the days !!
- Don Gillies
San Diego, CA, USA
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Date: 18 Oct 2007 07:49:48
From: James Thomson
Subject: Re: rim recommendations?
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"jim beam" <spamvortex@bad.example.net > a écrit:
> http://www.flickr.com/photos/38636024@N00/275085692/
> those are two separate plug pieces, not one.
That's quite unlike the solid 1-piece pin I recently pulled out of a dead
X517.
James Thomson
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Date: 18 Oct 2007 06:00:26
From: jim beam
Subject: Re: rim recommendations?
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James Thomson wrote:
> "jim beam" <spamvortex@bad.example.net> a �crit:
>
>> http://www.flickr.com/photos/38636024@N00/275085692/
>
>> those are two separate plug pieces, not one.
>
> That's quite unlike the solid 1-piece pin I recently pulled out of a dead
> X517.
>
> James Thomson
>
>
how can that be? that's a welded rim. if the two ends are electrically
flash welded, and they are, how can you possibly have a single piece
since the plug would interfere with the weld process?
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Date: 18 Oct 2007 19:47:39
From: James Thomson
Subject: Re: rim recommendations?
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>> That's quite unlike the solid 1-piece pin I recently pulled
>> out of a dead X517.
"jim beam" <spamvortex@bad.example.net > a écrit:
> how can that be? that's a welded rim. if the two ends are
> electrically flash welded, and they are, how can you possibly
> have a single piece since the plug would interfere with the
> weld process?
I don't know - I don't know much about welding: I'm just reporting what I
saw. I still have the pin, but I won't be able to lay hands on it before the
weekend, and I don't have a digital camera, but I should be able to post a
better description of it.
James Thomson
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Date: 20 Oct 2007 22:04:39
From: James Thomson
Subject: Re: rim recommendations?
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"James Thomson" <yosnappyj@hotmail.com > a écrit:
> I still have the pin, but I won't be able to lay hands on it before the
> weekend, and I don't have a digital camera, but I should be able
> to post a better description of it.
Well, my memory was playing tricks.
There are indeed two heavy little plug pieces, one either side of the joint,
each shaped to fit the box cavity of the rim, with a T-shaped channel
running through the extrusion. Welding flash fills the gap between the two.
My apologies.
James Thomson
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Date: 17 Oct 2007 21:06:59
From: Lou Holtman
Subject: Re: rim recommendations?
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Donald Gillies wrote:
> "James Thomson" <yosnappyj@hotmail.com> writes:
>
>> "Ben C" <spamspam@spam.eggs> a ecrit:
>
>>> I know, and I couldn't see any stickers in the pictures either. They do
>>> look very "low-profile"-- a similar sort of depth to MA-2s rather than
>>> the deeper U-shape of an Open Pro.
>
>> O'Grady was riding Ambrosio rims during the race, probably their "Nemesis"
>> model. You can see the telltale gold-coloured balance weights in this
>> picture:
>
>> http://www.cervelo.com/wallpaper/1/w037_2560ws.jpg
>> http://www.ambrosiospa.com/catalog_eng/
>
> I thought that a tire valve is even heavier than the rim's pin that
> holds it together (and, these are retro pinned tubular rims ??) Is
> the pin THAT HEAVY inside of a 420 gram tubular rim that it needs
> extra weight ??
>
> - Don Gillies
> San Diego, CA, USA
No, it is just a 'trade mark'.
Lou
--
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