IGH cabling setup and wonky indexing

[Lee]

Hi all. I'm directing this question to Anthony, but if any of you have
opinions, please speak up:

Currently, the cabling on my P/R's Nexus 8 IGH runs from a Jtek bar-
end shifter through one of the DT cable stops, to the chainstay cable
stops. The DT cable stop has a barrel adjuster that I use to fine-tune
the IGH indexing. Previously, I had the shifter cable sheathed in
housing for the entire run from shifter to the final chainstay stop,
with the cable zip-tied to the downtube.

I'm thinking about re-doing the shifter cabling as it's fraying and
the DT barrel adjuster isn't so great. I have two question before I
proceed with this, though:

1. Do you have a recommendation for a better, if possible, barrel
adjuster? I think I read that you like to place an inline adjuster
near the chainstay stop. How is this working out?

2. I've read that an IGH shifter cable run with full housing is less
wonky than one with exposed cabling. (My current setup has exposed
cabling between the DT stop and the first chainstay stop.) My indexing
has been pretty inconsistent, particularly in the direct drive gear.
Much of this is probably due to front loads sometimes displacing the
shifter cable. But, I feel like it's happening more often with my new
setup rather than the full-housing setup. Any opinions on full vs.
exposed?

Thanks!
Lee

[Longleaf Bicycles]

Currently, the cabling on my P/R's Nexus 8 IGH runs from a Jtek bar-

end shifter through one of the DT cable stops, to the chainstay cable

stops. The DT cable stop has a barrel adjuster that I use to fine-tune

the IGH indexing. Previously, I had the shifter cable sheathed in

housing for the entire run from shifter to the final chainstay stop,

with the cable zip-tied to the downtube.

. . .

Any opinions on full vs.

exposed?

Longleaf Bicycles

Lee,

My experience has been that I've never had a problem with full housing, and I've heard mixed reviews on split housing. I have split housing on my bike and one customer's and neither of us have had problems, but plenty of other people have. I can't think of any reason why split housing would be a problem, but many people have had it.

Anthony

[Fred Blasdel]

On Thu, Jan 7, 2010 at 9:55 AM, Lee <lee...@gmail.com> wrote:

1. Do you have a recommendation for a better, if possible, barrel
adjuster? I think I read that you like to place an inline adjuster
near the chainstay stop. How is this working out?

For the downtube stop I've been using the Shimano ones, but I just recently smashed the spring-loaded plastic part of it with my porteur rack... I'll have to find a correctly-threaded all-metal replacement for the adjuster bolt sometime.

For the hub end I've used this adjuster inline to great success, the OD of the threaded part is the same as a cable ferrule:

  http://www.sjscycles.co.uk/product.asp?pf_id=19256

I do not recommend using the frame's built-in chainstay stop -- it's too close to the hub's reaction arm stop. I had mine set up with a super-short piece of housing between the two stops for a long time, and it just caused frustration and didn't keep me from having to adjust it again when I replaced the wheel.

Right now I have it set up with housing from the Jtek shifter to the downtube, and then bare cable all the way to the hub. The shifting is a lot cleaner without the little zig-zag after the chainstay stop. I never have to adjust it anymore unless I've removed the rear wheel -- before the little piece of housing would shift around changing the cable length.

2. I've read that an IGH shifter cable run with full housing is less
wonky than one with exposed cabling. (My current setup has exposed
cabling between the DT stop and the first chainstay stop.) My indexing
has been pretty inconsistent, particularly in the direct drive gear.

That's odd, for me the direct drive (5) has always been the most reliable.

[Longleaf Bicycles]

Right now I have it set up with housing from the Jtek shifter to the downtube, and then bare cable all the way to the hub.

I want pictures.

What I did on the PV on the blog was install an STI cable stop into the threaded hole on the bb shell. So I have bare cable from the DT stop to the bb shell, then full housing all the way to the built in stop on the hub. No problems yet. On the PV the chainstay cable stop is so close to the hub I couldn't get der housing to make the zig-zag and even attempt the setup.

Anthony

Longleaf Bicycles
805 B North Fourth St..
Wilmington, North Carolina 28401
910.341.3049
longleafbicycles.com

[Lee]

Thanks Fred and Anthony, you've given me some things to think about.
Overall, I am going to attempt the split housing again, because I
think I can make it work and it's just a tidier arrangement.

Fred, at what point of the cabling run did you place the SA adjuster
you reference?

Also, I hadn't thought about the zig-zag section of housing between
the hub arm and chainstay stop. I wonder if that is affecting my
shifting?

Finally, I need to double-check if it's the 5th gear or the 4th where
I sometimes get slippage. I fear that it's the fifth and that I'm
damaging the hub. That's kind of what brought this project to the top
of the to-do list in the first place.

Best,
Lee

On Jan 7, 11:05 am, Longleaf Bicycles <longleafbicyc...@gmail.com>
wrote:

[Fred Blasdel]

On Thu, Jan 7, 2010 at 3:18 PM, Lee <lee...@gmail.com> wrote:

Fred, at what point of the cabling run did you place the SA adjuster
you reference?

It was at the very end: hub's reaction arm > SA adjuster > super-short housing > chainstay cable stop > bare wire through BB guide > downtube stop > housing > shifter

It's a major improvement even if you don't need the adjustability -- the hub normally uses a shitty bent metal insert clip as its housing stop, and with the SA adjuster you can remove it.

 

Also, I hadn't thought about the zig-zag section of housing between
the hub arm and chainstay stop. I wonder if that is affecting my
shifting?

For me there was a ton of resistance in there, which made it very difficult to shift down into the 1st gear sometimes.

[Mike J]

On Jan 7, 11:55 am, Lee <leec...@gmail.com> wrote:
<snip>

> 2. I've read that an IGH shifter cable run with full housing is less
> wonky than one with exposed cabling. (My current setup has exposed
> cabling between the DT stop and the first chainstay stop.) My indexing
> has been pretty inconsistent, particularly in the direct drive gear.
> Much of this is probably due to front loads sometimes displacing the
> shifter cable. But, I feel like it's happening more often with my new
> setup rather than the full-housing setup. Any opinions on full vs.
> exposed?

I have two bikes with Nexus IG hubs. In both cases, the housing runs
from the shifter to the arm on the hub. Neither bike has ever had any
shifting problems or need for adjustment.

I secure the cable housings to the down tube with cable clips (
http://www.velo-orange.com/agpacableclips.html) and use a single
plastic cable tie on the chain stay.

I think every cable stop/housing interface has its own seating
issues. The more stops, the more variability. A simple experiment
would be to run a single housing and see if there is any need for an
adjuster of any kind.

Mike Jenkins
Barrington, IL

[Fred Blasdel]

On Fri, Jan 8, 2010 at 5:22 AM, Mike J <mjenk...@gmail.com> wrote:

I think every cable stop/housing interface has its own seating
issues.  The more stops, the more variability.  A simple experiment
would be to run a single housing and see if there is any need for an
adjuster of any kind.

It's extremely difficult to get the exact right cable length with no adjustment anywhere. I've heard tell that you can measure with a caliper from the end of the housing if you use Shimano's insert clip stop at the hub, but that still doesn't account for cable stretch and the seating/bending of the housing.

If you're using one of the Shimano shifters that's easy, as they have a long barrel adjuster built in. The Jtek shifters just have a plain socket, and barring knowledge of other solutions the default idea is to use an adjustable downtube cable stop like other bikes with handlebar shifters.

The best option I know of for running housing all the way is to use this adjuster at the hub:

  http://www.sjscycles.co.uk/product.asp?pf_id=19256

Even if you don't need the adjustment, it makes for a much more reliable housing stop than the bent metal clip insert that the hub ships with.

 -- Fred

[Lee]

Thanks, Mike. In my initial setup, I had full-housing but it still
needed calibrating every once in a while. As Fred mentions, I used the
barrel adjuster built-in to the Shimano twist-grip shifter. Because I
also have a porteur rack on my rig, loads would sometimes interfere
with the cable run, necessitating some adjusting.

In my current setup, I'm using a Jtek bar-end shifter, which lacks a
built-in adjuster. I've been using an adjuster on the DT cable stop,
as so: http://www.velo-orange.com/dotucast.html.

I think the problem is that there is a lot of give in that DT
adjuster. And, since the load interference usually occurs between the
DT stop and the bar-end shifter, the cabling is susceptible to
displacement. So, I think I'd like to just secure the cable at the DT,
run the cable under the BB, and rely on an adjuster near the hub for
calibrating the indexing.

Oh yeah, Fred, I did check on my commute last night and it is the 5th
(direct drive) gear that sometimes has a problem engaging. Usually
this happens under heavy torque, like starting up from a light. And,
the initial cause is usually cable displacement from my commute stuff
loaded on the rack. But, that's the gear that feels it most.

Thanks again for the comments everyone,
Lee

On Fri, Jan 8, 2010 at 5:22 AM, Mike J <mjenk20...@gmail.com> wrote:
> I think every cable stop/housing interface has its own seating
> issues. The more stops, the more variability. A simple experiment
> would be to run a single housing and see if there is any need for an
> adjuster of any kind.

[Fred Blasdel]

On Fri, Jan 8, 2010 at 9:23 AM, Lee <lee...@gmail.com> wrote:

Oh yeah, Fred, I did check on my commute last night and it is the 5th
(direct drive) gear that sometimes has a problem engaging. Usually
this happens under heavy torque, like starting up from a light. And,
the initial cause is usually cable displacement from my commute stuff
loaded on the rack. But, that's the gear that feels it most.

It's quite likely that we have different hub models, there are about a dozen different iterations of the hub internals.

Mine is a Nexus Red Band from almost three years ago. There was a major revision when the Alfine came out, they added a third clutch to the works.

[jim g]

Why can't you use a typical Shimano DT cable stop/adjuster, plus run
full cable housing on either side of it?

Also, V-O and similar fender eyebolts are (I'm pretty sure) 5mm thread
-- I bet one of those, with the threaded section cut shorter, would
work great as an under-BB cable guide for full housing, installed in
the usual threaded hole in the BB shell.

http://ep.yimg.com/ca/I/yhst-84224226242177_2088_110258421

-Jim G

--
jimg at yojimg dot net

[Lee]

Thanks, Jim. That's not a bad idea about the fender eyebolts. I think
what's happening is that if I have a bulky load (which is the norm),
it'll displace the cable between the bars and DT enough to actually
pull the housing slightly out of the DT stop. (Although, this may just
mean I installed things incorrectly at the DT.) So, the real trouble
is with the cabling on the front end of the bike. I'm thinking I need
to secure this portion of the housing at the DT stop, but then I
couldn't use the barrel adjuster at the DT to calibrate the indexing.
So, I think I'll place an inline adjuster at the hub arm as Fred
suggests, to do the calibrating. BTW, I've rerouted the cabling
underneath the porteur rack and that is helping a little. Hopefully,
some of this makes sense, haha. Too much coffee at this point in the
day...

Best,
Lee

[Fred Blasdel]

On Fri, Jan 8, 2010 at 10:55 AM, jim g <yoj...@gmail.com> wrote:

Why can't you use a typical Shimano DT cable stop/adjuster, plus run
full cable housing on either side of it?

There'd be nothing to brace the housing on the lower side of the downtube stop!

Also, V-O and similar fender eyebolts are (I'm pretty sure) 5mm thread

-- I bet one of those, with the threaded section cut shorter, would
work great as an under-BB cable guide for full housing, installed in
the usual threaded hole in the BB shell.

There's also the mounts for the 3rd water bottle cage to use.

I had thought of using the stay-to-dropout clips which offset it to the side, but this is genius! A lot stronger, though permanent for the life of the cabling job, and you might need to use thin washers or a locknut (like a presta nut) to get the hole aligned.

I bought a pack of these but haven't used them yet since I never succumbed to full housing. I'll probably end up using them on the fork leg of a bike with a front drum brake:

  http://www.pricepoint.com/detail/17541-050_JAGST8-43-Brands-196-Jagwire-Cables/Jagwire-Alloy-Stick-On-Housing-Guide-3-Pack.htm

Another idea I had was to use a clamp-on downtube double-cable-stop just above the bottom bracket, so you'd have bare cable only for the length of the downtube, with housing run over the BB instead of bare cable through the wire guide.

Sturmey Archer also makes single clamp-on cable stops for a bunch of tubing sizes, including oval ones for chainstays.

[jim g]

On Fri, Jan 8, 2010 at 11:59 AM, Fred Blasdel <blas...@gmail.com> wrote:
>
> On Fri, Jan 8, 2010 at 10:55 AM, jim g <yoj...@gmail.com> wrote:
>>
>> Why can't you use a typical Shimano DT cable stop/adjuster, plus run
>> full cable housing on either side of it?
>
> There'd be nothing to brace the housing on the lower side of the downtube
> stop!

I don't think that'd matter, as long as you installed a ferrule over
the end of the housing. The adjuster screw at the DT stop doesn't
penetrate the stop, so turning the screw should still let it function
like an in-line adjuster. Though the housing on the lower side
doesn't have a recess to nestle into, that housing also isn't subject
to any movement, since the housing would be fastened to the frame
further down the down tube (at the 3rd bottle bosses, great idea)
and/or the BB shell.

> I bought a pack of these but haven't used them yet since I never succumbed
> to full housing. I'll probably end up using them on the fork leg of a bike
> with a front drum brake:
>   http://www.pricepoint.com/detail/17541-050_JAGST8-43-Brands-196-Jagwire-Cables/Jagwire-Alloy-Stick-On-Housing-Guide-3-Pack.htm

Hot damn, those look great for dynohub light wiring fork guides! And
they're even black!

[Fred Blasdel]

On Fri, Jan 8, 2010 at 1:03 PM, jim g <yoj...@gmail.com> wrote:

Though the housing on the lower side doesn't have a recess to nestle into, that housing also isn't subject to any movement

It'll definitely wiggle when in 1st gear, as the cable must be slack by several mm.

The coolest construction would be to tap the hole all the way through, replace the Shimano adjuster ferrule with a longer one, and use a thickish nut on the bottom end as a housing recess. As a bonus it'd be a much tighter locknut than a traditional one on the entrance side. A nylock nut might provide a nice snug fit too.

I think I've talked myself into making this mod, even if I don't do full housing :)

 

Hot damn, those look great for dynohub light wiring fork guides!  And
they're even black!

They're made of aluminium, and come in silver too!

They'd be a bit big even for coaxial wire, they're made to fit hydraulic brake hose. You might have to add some layers of heatshrink or something to beef  up the OD.

[franklyn]

This maybe a stupid question, but can one not use friction shifter on
an IGH?

Franklyn

[Fred Blasdel]

On Mon, Jan 11, 2010 at 12:39 PM, franklyn <frank...@gmail.com> wrote:

This maybe a stupid question, but can one not use friction shifter on
an IGH?

It works ok with a retrofriction if you're careful with most 3-speeds.

Any more than that and it doesn't work at all! They need 2x the cable pull as a normal derailleur. They're also insanely sensitive to alignment issues: a quarter turn on a barrel adjuster can make a huge difference (0.25mm!).

Using a friction shifter with a travel agent to double the cable pull would make it even fiddlier, since you're losing half your adjustment precision.

[Steve Palincsar]

On Mon, 2010-01-11 at 12:39 -0800, franklyn wrote:
> This maybe a stupid question, but can one not use friction shifter on
> an IGH?

The real question is, what happens if you're off? Those internal gear
hubs aren't made for a lot of high torque slamming and bamming, and
that's certainly what you're going to get when it slips out of gear
because you were a wee tiny bit off in your adjustment. Unlike with
derailleur systems, internal gear hubs don't have a way of giving you
feedback to let you know when you're perfectly aligned. The clearances
are a lot tighter, too.