Why many rear racks no longer triangulated?

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SA_SA_SA
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Why many rear racks no longer triangulated?

Postby SA_SA_SA » 16 Sep 2019, 9:16pm

It seems many rear pannier racks are no longer triangulated despite having enough struts to make it easy:

I wonder why?
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pwa
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Re: Why many rear racks no longer triangulated?

Postby pwa » 17 Sep 2019, 8:04am

Buy a proper one. Tubus for example. It will cost more but it will last.

mercalia
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Re: Why many rear racks no longer triangulated?

Postby mercalia » 17 Sep 2019, 9:36am

what does triangulated mean? a picture of both would be useful? The very nice large carrier that my dawes one down came with has lasted 20 years & has carried heavy weights
100_7335.JPG
click to enlarge
Last edited by mercalia on 17 Sep 2019, 9:43am, edited 1 time in total.

NetworkMan
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Re: Why many rear racks no longer triangulated?

Postby NetworkMan » 17 Sep 2019, 9:38am

I've always wondered just how much benefit the triangulation really brings.
I have three racks, an old Bor Yueh which is somewhat triangulated, a Topeak one which isn't and a Tubus Fly which isn't. The Tubus is made from largish diameter stainless steel tube and the other two from thin aluminium rod. The Tubus is by far the stiffest and the other two about are the same.

NetworkMan
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Re: Why many rear racks no longer triangulated?

Postby NetworkMan » 17 Sep 2019, 9:41am

mercalia wrote:what does triangulated mean? a picture of both would be useful?

Two of the struts meet the top of the rack close in to the middle so that viewed from the rear they form a triangle with the base at the bottom.
Edit: This Blackburn is an example. It's somewhat triangulated.
https://www.amazon.co.uk/Blackburn-Expe ... B000NORUTM
Last edited by NetworkMan on 17 Sep 2019, 9:47am, edited 1 time in total.

mercalia
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Re: Why many rear racks no longer triangulated?

Postby mercalia » 17 Sep 2019, 9:45am

NetworkMan wrote:
mercalia wrote:what does triangulated mean? a picture of both would be useful?

Two of the struts meet the top of the rack close in to the middle so that viewed from the rear they form a triangle with the base at the bottom.


so what is mine? - see picture above. I suppose it has the triangle feature
Last edited by mercalia on 17 Sep 2019, 9:50am, edited 1 time in total.

NetworkMan
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Re: Why many rear racks no longer triangulated?

Postby NetworkMan » 17 Sep 2019, 9:49am

mercalia wrote:
NetworkMan wrote:
mercalia wrote:what does triangulated mean? a picture of both would be useful?

Two of the struts meet the top of the rack close in to the middle so that viewed from the rear they form a triangle with the base at the bottom.


so what is mine? - see picture above

No I don't think so - see my edit for a picture. Look at how the rear struts are joined to the carrier top.

mercalia
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Re: Why many rear racks no longer triangulated?

Postby mercalia » 17 Sep 2019, 9:54am

NetworkMan wrote:
mercalia wrote:
NetworkMan wrote:Two of the struts meet the top of the rack close in to the middle so that viewed from the rear they form a triangle with the base at the bottom.


so what is mine? - see picture above

No I don't think so - see my edit for a picture. Look at how the rear struts are joined to the carrier top.


well maybe not rear trianngle but then my carrier is very wide so more a rectangle from the rear and of course not supported at the end so I can attach a rear light that you cant on the Balckburn

LollyKat
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Re: Why many rear racks no longer triangulated?

Postby LollyKat » 17 Sep 2019, 10:58am

NetworkMan wrote:I've always wondered just how much benefit the triangulation really brings.
I have three racks, an old Bor Yueh which is somewhat triangulated, a Topeak one which isn't and a Tubus Fly which isn't. The Tubus is made from largish diameter stainless steel tube and the other two from thin aluminium rod. The Tubus is by far the stiffest and the other two about are the same.


The Tubus Fly is triangulated, in two planes. I'm not surprised it is the stiffest.

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Vantage
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Re: Why many rear racks no longer triangulated?

Postby Vantage » 17 Sep 2019, 4:53pm

My bikes frame flexes more when loaded than my non triangulated rack. It's a fairly beefy Ibera thing and is strong enough for me to sit on (I've done it) but it's as square as spongebob squarepants.
The problem with triangulating a rack is that it results in a narrower top. If you don't use that bit then fine, but most tourers/commuters do.
Bill


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alexnharvey
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Re: Why many rear racks no longer triangulated?

Postby alexnharvey » 17 Sep 2019, 5:56pm

I don't understand. You can have triangulation and a top that extends beyond the triangular legs.

nigelnightmare
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Re: Why many rear racks no longer triangulated?

Postby nigelnightmare » 17 Sep 2019, 8:51pm

SA_SA_SA wrote:It seems many rear pannier racks are no longer triangulated despite having enough struts to make it easy:

I wonder why?


What do you mean by "triangulated"?
As Mercalia said "pictures would help".

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Vantage
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Re: Why many rear racks no longer triangulated?

Postby Vantage » 18 Sep 2019, 7:51am

As network man already stated, if you look at a rack from behind as its fitted to the bike, you'll see the struts either go straight up at 90° which isn't triangulated, or they'll go up at an angle towards each other which is triangulated.

big_ae3eff7a-3a77-4dc7-88fa-40261a4358e3.jpg
Triangulated


61ozsXYTX9L._SL1200_.jpg
Non triangulated
Bill


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Brucey
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Re: Why many rear racks no longer triangulated?

Postby Brucey » 18 Sep 2019, 9:55am

Blackburn were amongst the first, if no the first, to have triangulated stays


By 1980 they were well established and had started to make adjustable models as well as ones of fixed geometry.

Image

Although not indicated here the fixed geometry racks were available in (three?) different sizes to fit different sized framesets.

1981

Image

the lateral triangulation made these racks way stiffer (especially considering the weight of them) than almost any that had been previously available.

These days you can buy racks that are both triangulated and made in tubular steel, which is probably the most efficient way of making a lightweight rack that is also very stiff/strong.

cheers
Last edited by Brucey on 18 Sep 2019, 10:00am, edited 2 times in total.
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mercalia
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Re: Why many rear racks no longer triangulated?

Postby mercalia » 18 Sep 2019, 9:58am

well you can only have a triangulated rack if the top is narrow - unlike mine which is very wide, unless you dont support the top some where, as in Bruceys picture above? so cant see why triangulation is a preferable. My rack seems very rigid - has 4 ribs across the top for one unlike Bruceys just 2 and also 2 internal ones not just the ourside frame

100_7338.JPG
Last edited by mercalia on 18 Sep 2019, 10:15am, edited 2 times in total.