Tektro Yoke, what is the Philips Screw for?

On 14/12/2015 22:54, AMuzi wrote:

Older cantilever designs unwind to catch the arm(s) on a spoke when
either wire, linked by either method, fails.

That usually rips out a spoke or two and/or the cantilever boss from the
frame/fork in a less dramatic and less injurious way than a transverse
stuck on a tire.

I'm struggling to picture that - got anything to help describe it?

On Monday, December 14, 2015 at 6:46:43 PM UTC-5, sms wrote:
On 12/14/2015 1:54 PM, Doug Landau wrote:

Yabbut the yoke is not going to get caught in the knobs, being too big to fit up against them squarely, right? It's going to get bounced away by them

Without the main wire in place. the yoke doesn't fall down onto the
tire. The straddle cable is stiff enough that it comes down a little as
the springs in the cantilever pull the arms outward. The yoke, with its
Allen screws tightened, gives the straddle wire more rigidity.

You can see a photo of the straddle wire and yoke, with the brake cable
disconnected, at http://oi65.tinypic.com/ioi6j4.jpg. It stays way
above the tire.

With the cheap yokes, the yoke would fall off if the brake cable broke,
and the straddle cable could come out of the right cantilever arm if it
were long enough that there was no spring tension on it anymore.

Part of the advantage of the wider yoke may be that you can have a
shorter straddle cable that's less likely to fall onto the tire.

SMS and truth are oxymoromns.

Yet more outright lies from SMS. Look at the image he provided and you can't even see the brake cable but you can see the DISCONNECTED STRADDLE cable.

I'd believe A. Muzi LONG before I'd believe ANYTHING that SMS says especially if the result in failure of the item under discussion could lead to a serious injury such as a cantilever straddle cable fouling the front tire.

On Monday, December 14, 2015 at 7:00:23 PM UTC-5, Clive George wrote:
On 14/12/2015 22:54, AMuzi wrote:

Older cantilever designs unwind to catch the arm(s) on a spoke when
either wire, linked by either method, fails.

That usually rips out a spoke or two and/or the cantilever boss from the
frame/fork in a less dramatic and less injurious way than a transverse
stuck on a tire.

I'm struggling to picture that - got anything to help describe it?

The arms of old-style cantilevers were long and stuck out straight from the forks/seatstays. The spring tension could result in the arm itself pivoting downwards and around until the now upside down cantlever arm hit the spokes.

Cheers

On 15/12/2015 01:08, Sir Ridesalot wrote:
On Monday, December 14, 2015 at 7:00:23 PM UTC-5, Clive George wrote:
On 14/12/2015 22:54, AMuzi wrote:

Older cantilever designs unwind to catch the arm(s) on a spoke when
either wire, linked by either method, fails.

That usually rips out a spoke or two and/or the cantilever boss from the
frame/fork in a less dramatic and less injurious way than a transverse
stuck on a tire.

I'm struggling to picture that - got anything to help describe it?

The arms of old-style cantilevers were long and stuck out straight from the forks/seatstays. The spring tension could result in the arm itself pivoting downwards and around until the now upside down cantlever arm hit the spokes.

Ah, got it :-)

On 14/12/2015 23:46, sms wrote:
On 12/14/2015 1:54 PM, Doug Landau wrote:

Yabbut the yoke is not going to get caught in the knobs, being too big
to fit up against them squarely, right? It's going to get bounced
away by them

Without the main wire in place. the yoke doesn't fall down onto the
tire. The straddle cable is stiff enough that it comes down a little as
the springs in the cantilever pull the arms outward. The yoke, with its
Allen screws tightened, gives the straddle wire more rigidity.

You can see a photo of the straddle wire and yoke, with the brake cable
disconnected, at http://oi65.tinypic.com/ioi6j4.jpg. It stays way
above the tire.

And the same cable without the yoke?

On 12/14/2015 6:00 PM, Clive George wrote:
On 14/12/2015 22:54, AMuzi wrote:

Older cantilever designs unwind to catch the arm(s) on a
spoke when
either wire, linked by either method, fails.

That usually rips out a spoke or two and/or the cantilever
boss from the
frame/fork in a less dramatic and less injurious way than
a transverse
stuck on a tire.

I'm struggling to picture that - got anything to help
describe it?



this style & copies:
https://vintagebicycle.files.wordpre...4/r1017370.jpg

I only know this because we replace the twisted and broken
brake studs afterwards. Again, not all that common a failure.

The most popular low profile current cantilevers have less
spring travel and stick up not out so unlikely to ever do that.

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

On Monday, December 14, 2015 at 6:46:43 PM UTC-5, sms wrote:
On 12/14/2015 1:54 PM, Doug Landau wrote:

Yabbut the yoke is not going to get caught in the knobs, being too big to fit up against them squarely, right? It's going to get bounced away by them

Without the main wire in place. the yoke doesn't fall down onto the
tire. The straddle cable is stiff enough that it comes down a little as
the springs in the cantilever pull the arms outward. The yoke, with its
Allen screws tightened, gives the straddle wire more rigidity.

You can see a photo of the straddle wire and yoke, with the brake cable
disconnected, at http://oi65.tinypic.com/ioi6j4.jpg. It stays way
above the tire.

With the cheap yokes, the yoke would fall off if the brake cable broke,
and the straddle cable could come out of the right cantilever arm if it
were long enough that there was no spring tension on it anymore.

Part of the advantage of the wider yoke may be that you can have a
shorter straddle cable that's less likely to fall onto the tire.

available in CF ?

On 12/15/2015 5:52 AM, AMuzi wrote:
On 12/14/2015 6:00 PM, Clive George wrote:
On 14/12/2015 22:54, AMuzi wrote:

Older cantilever designs unwind to catch the arm(s) on a
spoke when
either wire, linked by either method, fails.

That usually rips out a spoke or two and/or the cantilever
boss from the
frame/fork in a less dramatic and less injurious way than
a transverse
stuck on a tire.

I'm struggling to picture that - got anything to help
describe it?



this style & copies:
https://vintagebicycle.files.wordpre...4/r1017370.jpg

I only know this because we replace the twisted and broken brake studs
afterwards. Again, not all that common a failure.

The most popular low profile current cantilevers have less spring travel
and stick up not out so unlikely to ever do that.

It's not just that. As I showed in the photo earlier, if the main brake
cable breaks, the cantilevers won't spread apart so far that they pull
the straddle cable onto the tire.

I don't know how old is "old" but the bicycle where the photo is from is
circa 1998 http://tinypic.com/view.php?pic=ioi6j4&s=9.

I can see the appeal of the Z cable system, it eliminates the problem of
a straddle cable causing a crash if the main cable breaks or if the bolt
on the yoke is not tight. If either the Z cable or the main cable break
it should not cause a wheel lock-up problem.