Rear derailleur cable loop - conflicting advice (meant to post here!)

[Josh Hassol]

I accidentally posted this to RBM, and have re-posted here. Sorry if
you're seeing this twice . . .

If you've read the Park Tool website advice on cutting cable housing,
you may have noticed that Park recommends a longer "loop" at the rear
derailleur than most bikes come with from the factory. This longer
loop achieves a straight cable entry into the derailleur, which helps
provide smoother shifting. So I set my bike up that way, and it works
fine.

On the other hand, the mechanic at the LBS saw my bike and said that my

derailleur cable was "much too long." He said that the longer cable
loop could get "sucked into the rear wheel" by which I assume he meant
it could get forced into the spokes if another rider's wheel pushed
into it. I noticed that all the bikes at the shop, like the majority
of bikes you see, had really short cable loops at the derailleur, and
that, consequently, the cables did not insert into the derailleurs in a

nice, straight line. But does it matter?


Does anybody have an opinion on this? Is the Park advice just overly
compulsive?

 

[Art Harris]

Josh Hassol wrote:
> If you've read the Park Tool website advice on cutting cable housing,
> you may have noticed that Park recommends a longer "loop" at the rear
> derailleur than most bikes come with from the factory.

Yes, that's what I prefer. Greater bend radius means less friction
(within reason).

Art Harris

 

[Booker C. Bense]

-----BEGIN PGP SIGNED MESSAGE-----

In article <[email protected]>,
Josh Hassol <[email protected]> wrote:
>I accidentally posted this to RBM, and have re-posted here. Sorry if
>you're seeing this twice . . .
>
>If you've read the Park Tool website advice on cutting cable housing,
>you may have noticed that Park recommends a longer "loop" at the rear
>derailleur than most bikes come with from the factory. This longer
>loop achieves a straight cable entry into the derailleur, which helps
>provide smoother shifting. So I set my bike up that way, and it works
>fine.
>
>On the other hand, the mechanic at the LBS saw my bike and said that my
>
>derailleur cable was "much too long." He said that the longer cable
>loop could get "sucked into the rear wheel" by which I assume he meant
>it could get forced into the spokes if another rider's wheel pushed
>into it.

_ Exactly what is it going to catch on? Unless you still have the
spoke reflector on there, I can't imagine what could grab the
loop of cable. I keep mine relatively long I've never had a
problem. Most new bikes I look at don't have optimal cable setups
IHMO.


> I noticed that all the bikes at the shop, like the majority
>of bikes you see, had really short cable loops at the derailleur, and
>that, consequently, the cables did not insert into the derailleurs in a
>
>nice, straight line. But does it matter?
>
>
>Does anybody have an opinion on this? Is the Park advice just overly
>compulsive?

_ Fresh out of the shop it probably doesn't matter either way,
but smooth bends will give longer cable life and stand up to the
abuse of the real world better.

Sheldon says it's a good idea...


http://www.sheldonbrown.com/cables.html


_ Booker C. Bense

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[[email protected]]

right. try a woven or braided housing in grey at Trek? not the shimano
parallel wire housing: that's brake diameter leaving a reservoir for
teflon wax. try feeding the inner housing tip into a stop that has a
holding device for the tip. then a strap oer the housing to hold the
housing flat just aft of the housing/cable stop - so when yawl clean
the chain, the deray cable stays taught in its extra length bound loop.

 

[Roger L.]

Josh Hassol wrote:

> If you've read the Park Tool website advice on cutting cable housing,
> you may have noticed that Park recommends a longer "loop" at the rear
> derailleur than most bikes come with from the factory. This longer
> loop achieves a straight cable entry into the derailleur, which helps
> provide smoother shifting. So I set my bike up that way, and it works
> fine.
>
> On the other hand, the mechanic at the LBS saw my bike and said that
> my derailleur cable was "much too long." He said that the longer cable
> loop could get "sucked into the rear wheel" by which I assume he meant
> it could get forced into the spokes if another rider's wheel pushed
> into it. I noticed that all the bikes at the shop, like the majority
> of bikes you see, had really short cable loops at the derailleur, and
> that, consequently, the cables did not insert into the derailleurs in
> a nice, straight line. But does it matter?
>

Josh

If you want really compact and really smooth, try an Avid rollamig:

http://www.cambriabike.com/shopexd.asp?id=8611

The rollamig really seems to aid positive rear shifting and pretty much
eliminates the loop into the rear derailleur.

 

[Doug B.]

On Fri, 26 May 2006 18:23:30 -0000, "Roger L. wrote:

>Josh Hassol wrote:
>
>> If you've read the Park Tool website advice on cutting cable housing,
>> you may have noticed that Park recommends a longer "loop" at the rear
>> derailleur than most bikes come with from the factory. This longer
>> loop achieves a straight cable entry into the derailleur, which helps
>> provide smoother shifting. So I set my bike up that way, and it works
>> fine.
>>
>> On the other hand, the mechanic at the LBS saw my bike and said that
>> my derailleur cable was "much too long." He said that the longer cable
>> loop could get "sucked into the rear wheel" by which I assume he meant
>> it could get forced into the spokes if another rider's wheel pushed
>> into it. I noticed that all the bikes at the shop, like the majority
>> of bikes you see, had really short cable loops at the derailleur, and
>> that, consequently, the cables did not insert into the derailleurs in
>> a nice, straight line. But does it matter?
>>
>
>Josh
>
>If you want really compact and really smooth, try an Avid rollamig:
>
>http://www.cambriabike.com/shopexd.asp?id=8611
>
>The rollamig really seems to aid positive rear shifting and pretty much
>eliminates the loop into the rear derailleur.

Do you have a picture of this thing installed?

 

[[email protected]]

On Fri, 26 May 2006 19:26:53 -0400, Doug B. <[email protected]>
wrote:

>On Fri, 26 May 2006 18:23:30 -0000, "Roger L. wrote:
>
>>Josh Hassol wrote:
>>
>>> If you've read the Park Tool website advice on cutting cable housing,
>>> you may have noticed that Park recommends a longer "loop" at the rear
>>> derailleur than most bikes come with from the factory. This longer
>>> loop achieves a straight cable entry into the derailleur, which helps
>>> provide smoother shifting. So I set my bike up that way, and it works
>>> fine.
>>>
>>> On the other hand, the mechanic at the LBS saw my bike and said that
>>> my derailleur cable was "much too long." He said that the longer cable
>>> loop could get "sucked into the rear wheel" by which I assume he meant
>>> it could get forced into the spokes if another rider's wheel pushed
>>> into it. I noticed that all the bikes at the shop, like the majority
>>> of bikes you see, had really short cable loops at the derailleur, and
>>> that, consequently, the cables did not insert into the derailleurs in
>>> a nice, straight line. But does it matter?
>>>
>>
>>Josh
>>
>>If you want really compact and really smooth, try an Avid rollamig:
>>
>>http://www.cambriabike.com/shopexd.asp?id=8611
>>
>>The rollamig really seems to aid positive rear shifting and pretty much
>>eliminates the loop into the rear derailleur.
>
>Do you have a picture of this thing installed?

Dear Doug,

http://www.pricepoint.com/detail/11...Avid-Rollamajig---Derailleur-Cable-Device.htm

Cheers,

Carl Fogel

 

[Qui si parla Campagnolo]

Josh Hassol wrote:
> I accidentally posted this to RBM, and have re-posted here. Sorry if
> you're seeing this twice . . .
>
> If you've read the Park Tool website advice on cutting cable housing,
> you may have noticed that Park recommends a longer "loop" at the rear
> derailleur than most bikes come with from the factory. This longer
> loop achieves a straight cable entry into the derailleur, which helps
> provide smoother shifting. So I set my bike up that way, and it works
> fine.
>
> On the other hand, the mechanic at the LBS saw my bike and said that my
>
> derailleur cable was "much too long." He said that the longer cable
> loop could get "sucked into the rear wheel" by which I assume he meant
> it could get forced into the spokes if another rider's wheel pushed
> into it. I noticed that all the bikes at the shop, like the majority
> of bikes you see, had really short cable loops at the derailleur, and
> that, consequently, the cables did not insert into the derailleurs in a
>
> nice, straight line. But does it matter?

First the bike shop guy is FOS, There is no way on earth the segment
can get 'sucked into the rear wheel...what ****.

...second, longer is always better than shorter as a short segment at
the RD ends up getting kinked at the der, making for less than smooth
inner wire opreration, making for poor RD action.
>
>
> Does anybody have an opinion on this? Is the Park advice just overly
> compulsive?

 

[TonyKiz]

Get an Avid Rollamig and then you can shorten up the loop as well as have
smoother, more reliable shifting.

http://www.sram.com/en/avid/cablesystems/rollamajig/


"Art Harris" <[email protected]> wrote in message
news:[email protected]...
> Josh Hassol wrote:
> > If you've read the Park Tool website advice on cutting cable housing,
> > you may have noticed that Park recommends a longer "loop" at the rear
> > derailleur than most bikes come with from the factory.
>
> Yes, that's what I prefer. Greater bend radius means less friction
> (within reason).
>
> Art Harris
>

 

[chuck]

On 2006-05-27, TonyKiz <[email protected]> wrote:
> Get an Avid Rollamig and then you can shorten up the loop as well as have
> smoother, more reliable shifting.
>
> http://www.sram.com/en/avid/cablesystems/rollamajig/
>
>

This thing is sorta built into the x-7 derailleur that I used to replace
the 105 that came on the bike. It seems to shift better than I remember
the 105 shifting, but I replaced the chain and cassette too. To use the
X-7, I had to cut the loop in half.

> "Art Harris" <[email protected]> wrote in message
> news:[email protected]...
>> Josh Hassol wrote:
>> > If you've read the Park Tool website advice on cutting cable housing,
>> > you may have noticed that Park recommends a longer "loop" at the rear
>> > derailleur than most bikes come with from the factory.
>>
>> Yes, that's what I prefer. Greater bend radius means less friction
>> (within reason).
>>
>> Art Harris
>>
>
>

 

[Josh Hassol]

Qui si parla Campagnolo wrote:
>
> First the bike shop guy is FOS, There is no way on earth the segment
> can get 'sucked into the rear wheel...what ****.
>
> ..second, longer is always better than shorter as a short segment at
> the RD ends up getting kinked at the der, making for less than smooth
> inner wire opreration, making for poor RD action.

That's what I figured. I left the cable as is, with a loop long enough
that the cable inserts nice and straight into the derailleur. It
shifts smoothly and accurately.