Why did rear derailleur cable move from top to bottom of chainstay?

On 8/8/2019 8:55 PM, jbeattie wrote:
On Thursday, August 8, 2019 at 1:39:57 PM UTC-7, AMuzi wrote:
On 8/8/2019 2:54 PM, Tom Kunich wrote:
On Tuesday, August 6, 2019 at 7:34:51 AM UTC-7, Sir Ridesalot wrote:
I was looking at a couple of my old bicycle frames with the rear derailleur cable routed along the top of the chainstay. I'm curious now. Why did the rear derailleur cable routing get moved to under the chainstay?

Cheers

Andrew told us about when it happened but not why. The rear derailleur cable was moved when the downtube friction shifters were moved to Shimano Brifters in the 70's.

Running the cables under the downtube gave the cables a cleaner run from the head tube to the under bottom bracket plastic runner.


First modern under-BB guides were steel, mid 1970s.
First nylon gear plate was Vitus in 1979.
First integrated shifter was Shimano 1990, followed by
Campagnolo Ergo a year or so later.

With the Vitus, the cables were structural. https://tinyurl.com/y4kh5o3g It was the first cable-stay frame design and ensured that the tubes would not separate in the event of epoxy failure.

Just curious: Were there many joint failures in Vitus frames? I don't
remember.


--
- Frank Krygowski

On 8/8/2019 9:10 PM, Frank Krygowski wrote:
On 8/8/2019 8:55 PM, jbeattie wrote:
On Thursday, August 8, 2019 at 1:39:57 PM UTC-7, AMuzi wrote:
On 8/8/2019 2:54 PM, Tom Kunich wrote:
On Tuesday, August 6, 2019 at 7:34:51 AM UTC-7, Sir
Ridesalot wrote:
I was looking at a couple of my old bicycle frames with
the rear derailleur cable routed along the top of the
chainstay. I'm curious now. Why did the rear derailleur
cable routing get moved to under the chainstay?

Cheers

Andrew told us about when it happened but not why. The
rear derailleur cable was moved when the downtube
friction shifters were moved to Shimano Brifters in the
70's.

Running the cables under the downtube gave the cables a
cleaner run from the head tube to the under bottom
bracket plastic runner.


First modern under-BB guides were steel, mid 1970s.
First nylon gear plate was Vitus in 1979.
First integrated shifter was Shimano 1990, followed by
Campagnolo Ergo a year or so later.

With the Vitus, the cables were structural.
https://tinyurl.com/y4kh5o3g It was the first cable-stay
frame design and ensured that the tubes would not separate
in the event of epoxy failure.

Just curious: Were there many joint failures in Vitus
frames? I don't remember.



No, not numerous but some. The material is flexible enough
that one might pull the joint apart enough to clean it and
rebond with a better epoxy.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Thursday, August 8, 2019 at 8:55:47 PM UTC-4, jbeattie wrote:
On Thursday, August 8, 2019 at 1:39:57 PM UTC-7, AMuzi wrote:
On 8/8/2019 2:54 PM, Tom Kunich wrote:
On Tuesday, August 6, 2019 at 7:34:51 AM UTC-7, Sir Ridesalot wrote:
I was looking at a couple of my old bicycle frames with the rear derailleur cable routed along the top of the chainstay. I'm curious now. Why did the rear derailleur cable routing get moved to under the chainstay?

Cheers

Andrew told us about when it happened but not why. The rear derailleur cable was moved when the downtube friction shifters were moved to Shimano Brifters in the 70's.

Running the cables under the downtube gave the cables a cleaner run from the head tube to the under bottom bracket plastic runner.


First modern under-BB guides were steel, mid 1970s.
First nylon gear plate was Vitus in 1979.
First integrated shifter was Shimano 1990, followed by
Campagnolo Ergo a year or so later.

With the Vitus, the cables were structural. https://tinyurl.com/y4kh5o3g It was the first cable-stay frame design and ensured that the tubes would not separate in the event of epoxy failure.

-- Jay Beattie.

Seeing as the headtube joints were in front of the downtube shifters, how would shifter cables keep the frame together if a doubtube or toptube joint failed at the headtube?

Cheers

On Thursday, August 8, 2019 at 9:42:06 PM UTC-7, Sir Ridesalot wrote:
On Thursday, August 8, 2019 at 8:55:47 PM UTC-4, jbeattie wrote:
On Thursday, August 8, 2019 at 1:39:57 PM UTC-7, AMuzi wrote:
On 8/8/2019 2:54 PM, Tom Kunich wrote:
On Tuesday, August 6, 2019 at 7:34:51 AM UTC-7, Sir Ridesalot wrote:
I was looking at a couple of my old bicycle frames with the rear derailleur cable routed along the top of the chainstay. I'm curious now. Why did the rear derailleur cable routing get moved to under the chainstay?

Cheers

Andrew told us about when it happened but not why. The rear derailleur cable was moved when the downtube friction shifters were moved to Shimano Brifters in the 70's.

Running the cables under the downtube gave the cables a cleaner run from the head tube to the under bottom bracket plastic runner.


First modern under-BB guides were steel, mid 1970s.
First nylon gear plate was Vitus in 1979.
First integrated shifter was Shimano 1990, followed by
Campagnolo Ergo a year or so later.

With the Vitus, the cables were structural. https://tinyurl.com/y4kh5o3g It was the first cable-stay frame design and ensured that the tubes would not separate in the event of epoxy failure.

-- Jay Beattie.

Seeing as the headtube joints were in front of the downtube shifters, how would shifter cables keep the frame together if a doubtube or toptube joint failed at the headtube?

You had to make sure you pulled backwards on the bars. It was a very tricky bike to ride. Sean Kelly worked very hard holding the front end together, as you can see from this picture. https://live.staticflickr.com/2044/2...ce52bd4b3d.jpg

-- Jay Beattie.

On Thursday, August 8, 2019 at 1:12:55 PM UTC-7, Frank Krygowski wrote:
On 8/8/2019 3:54 PM, Tom Kunich wrote:
On Tuesday, August 6, 2019 at 7:34:51 AM UTC-7, Sir Ridesalot wrote:
I was looking at a couple of my old bicycle frames with the rear derailleur cable routed along the top of the chainstay. I'm curious now. Why did the rear derailleur cable routing get moved to under the chainstay?

Cheers

I'll ignore the mistakes in your other post (yet again). I'll note just
the bike tech mistakes below.


Andrew told us about when it happened but not why. The rear derailleur cable was moved when the downtube friction shifters were moved to Shimano Brifters in the 70's.

Sorry, that's wrong.

Running the cables under the downtube gave the cables a cleaner run from the head tube to the under bottom bracket plastic runner.

But since the under bottom bracket guides appeared earlier, that's not
the reason.




--
- Frank Krygowski


The non-chain drive appeared in 1896. So tell us your usual stupid rant of why there were under-BB shifter runs. As someone that actually worked on those sorts of bikes I know that they were not plastic runs but steel and rapidly rusted and both froze the shifters and broke the cables. I would like to see just one single day go by without some totally ignorant statement from you.