chain watchers

On Tue, 17 Feb 2009 15:28:49 -0600, A Muzi
wrote:

John Forrest Tomlinson wrote:
http://www.cyclingnews.com/road/2009...s_chain_keeper
Is this a commercial product? Any idea what brand, etc?
What about this:
http://www.cyclingnews.com/road/2009...chain_keeper_2

First photo is a Jump Stop, available at any competent LBS, as are Third
Eye chain watchers. Both work well, under $20. Jump Stop is more
adjustable and hence often easier to fit.

Second photo seems likely to be a mechanic-fabricated guide or at least
I've never seen such available as a product.

Dear Andrew,

It's nice to have someone with your experience confirm that the snazzy
chain-watcher in the second photo is uncommon.

I looked for similar chain-watchers a while ago, but I found nothing
but various nifty-looking examples that looked suspiciously different
from each other. They were so nice-looking that I kept thinking like
John that maybe there's a commercial version, but I suspect that each
one has to be hand-made to fit a specific combination of frame, bottom
bracket, derailleur, and sprocket.

Chalo can probably bend one into shape with his bare hands, but my
misadventures trying to adapt a pair of thorn-scrapers that Frank
Krygowski sent me suggest that I'd end up with a jammed crank.

Cheers,

Carl Fogel

On Tue, 17 Feb 2009 16:32:22 -0700, wrote:

On Tue, 17 Feb 2009 06:43:50 -0800 (PST), "
wrote:

It's been around for years:

http://www.biketiresdirect.com/p3ech...watcher/pp.htm

I used to use them on tandems with a big drop from the middle to the
small ring.

-Brian

Dear Brian,

Yes, there are several commercial round-seat-tube chain-watchers--I
use one.

But I think that John is looking for the kind that hang off a front
derailleur or use a different clamp to work on non-round seat-tubes.

Yes -- or more precisely for a seat-tube that's round but varies in
diameter.

On Wed, 18 Feb 2009 00:00:17 GMT, John Forrest Tomlinson
wrote:

On Tue, 17 Feb 2009 16:32:22 -0700, wrote:

On Tue, 17 Feb 2009 06:43:50 -0800 (PST), "
wrote:

It's been around for years:

http://www.biketiresdirect.com/p3ech...watcher/pp.htm

I used to use them on tandems with a big drop from the middle to the
small ring.

-Brian

Dear Brian,

Yes, there are several commercial round-seat-tube chain-watchers--I
use one.

But I think that John is looking for the kind that hang off a front
derailleur or use a different clamp to work on non-round seat-tubes.

Yes -- or more precisely for a seat-tube that's round but varies in
diameter.

Dear John,

Two more examples of the hang-it-off-the-derailleur design:

Metal rod 2008 TDF:
http://tour-de-france.velonews.com/photo/39313

Metal rod 2008 Roubaix:

http://www.cyclingnews.com/photos/20...ecial_spare_FD
or http://tinyurl.com/42mw6u

Just a carefully bent rod welded to a big washer-plate that the
derailleur nut clamps against the derailleur

The second one looks a little more like a production piece, but that
may be just wishful thinking.

Cheers,

Carl Fogel

In article ,
John Forrest Tomlinson wrote:

On Tue, 17 Feb 2009 16:32:22 -0700, wrote:

On Tue, 17 Feb 2009 06:43:50 -0800 (PST), "
wrote:

It's been around for years:

http://www.biketiresdirect.com/p3ech...watcher/pp.htm

I used to use them on tandems with a big drop from the middle to the
small ring.

-Brian

Dear Brian,

Yes, there are several commercial round-seat-tube chain-watchers--I
use one.

But I think that John is looking for the kind that hang off a front
derailleur or use a different clamp to work on non-round seat-tubes.

Yes -- or more precisely for a seat-tube that's round but varies in
diameter.

Wild. Flaring towards the BB shell? What frame?

--
Ryan Cousineau http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

On Tue, 17 Feb 2009 18:31:04 -0700, wrote:

Two more examples of the hang-it-off-the-derailleur design:

Metal rod 2008 TDF:
http://tour-de-france.velonews.com/photo/39313

Metal rod 2008 Roubaix:

http://www.cyclingnews.com/photos/20...ecial_spare_FD
or http://tinyurl.com/42mw6u

Just a carefully bent rod welded to a big washer-plate that the
derailleur nut clamps against the derailleur

The second one looks a little more like a production piece, but that
may be just wishful thinking.

Thanks

On Wed, 18 Feb 2009 01:39:37 GMT, Ryan Cousineau
wrote:

In article ,
John Forrest Tomlinson wrote:

On Tue, 17 Feb 2009 16:32:22 -0700, wrote:

On Tue, 17 Feb 2009 06:43:50 -0800 (PST), "
wrote:

It's been around for years:

http://www.biketiresdirect.com/p3ech...watcher/pp.htm

I used to use them on tandems with a big drop from the middle to the
small ring.

-Brian

Dear Brian,

Yes, there are several commercial round-seat-tube chain-watchers--I
use one.

But I think that John is looking for the kind that hang off a front
derailleur or use a different clamp to work on non-round seat-tubes.

Yes -- or more precisely for a seat-tube that's round but varies in
diameter.

Wild. Flaring towards the BB shell? What frame?
A Trek Madone and also an older Trek OCLV. It's pretty common on
carbon frames for that to happen.

In article ,
John Forrest Tomlinson wrote:

On Wed, 18 Feb 2009 01:39:37 GMT, Ryan Cousineau
wrote:

In article ,
John Forrest Tomlinson wrote:

On Tue, 17 Feb 2009 16:32:22 -0700, wrote:

On Tue, 17 Feb 2009 06:43:50 -0800 (PST), "
wrote:

It's been around for years:

http://www.biketiresdirect.com/p3ech...watcher/pp.htm

I used to use them on tandems with a big drop from the middle to the
small ring.

-Brian

Dear Brian,

Yes, there are several commercial round-seat-tube chain-watchers--I
use one.

But I think that John is looking for the kind that hang off a front
derailleur or use a different clamp to work on non-round seat-tubes.

Yes -- or more precisely for a seat-tube that's round but varies in
diameter.

Wild. Flaring towards the BB shell? What frame?
A Trek Madone and also an older Trek OCLV. It's pretty common on
carbon frames for that to happen.

I know about the Madone's shark fin, but I didn't know the older OCLVs
flared.

--
Ryan Cousineau http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

On Feb 17, 5:27*pm, A Muzi wrote:
John Forrest Tomlinson wrote:
http://www.cyclingnews.com/road/2009.../tech.php?id=/...
Is this a commercial product? Any idea what brand, etc?
What about this:
http://www.cyclingnews.com/road/2009.../tech.php?id=/...
*A Muzi wrote:
First photo is a Jump Stop, available at any competent LBS, as are Third
Eye chain watchers. Both work well, under $20. Jump Stop is more
adjustable and hence often easier to fit.
Second photo seems likely to be a mechanic-fabricated guide or at least
I've never seen such available as a product.
wrote:
Thats not a N'Gear Jump Stop. *Picture has the bolt head protruding,
Jump Stop has the bolt head sunk into the plastic. *Jump Stop also has
the metal guide come around from the back of the seattube.
http://www.jensonusa.com/store/produ...Jump+Start+Cha...
Photo in question.
http://www.cyclingnews.com/road/2009.../tech.php?id=/....

Russel, you're right.
Uncannily similar, a Jump Stop analogue?
--
Andrew Muzi
* www.yellowjersey.org/
* Open every day since 1 April, 1971- Hide quoted text -

- Show quoted text -

I'd guess its homemade by the shop mechanic, for some reason. Not
sure why someone would make one of these from scratch when you can
just buy them for $10 on the internet. But the maker probably looked
at the N'Gear Jump Stop and modeled it after that one.

On Wed, 18 Feb 2009 06:49:38 -0800 (PST), "
wrote:

On Feb 17, 5:27*pm, A Muzi wrote:
John Forrest Tomlinson wrote:
http://www.cyclingnews.com/road/2009.../tech.php?id=/...
Is this a commercial product? Any idea what brand, etc?
What about this:
http://www.cyclingnews.com/road/2009.../tech.php?id=/...
*A Muzi wrote:
First photo is a Jump Stop, available at any competent LBS, as are Third
Eye chain watchers. Both work well, under $20. Jump Stop is more
adjustable and hence often easier to fit.
Second photo seems likely to be a mechanic-fabricated guide or at least
I've never seen such available as a product.
wrote:
Thats not a N'Gear Jump Stop. *Picture has the bolt head protruding,
Jump Stop has the bolt head sunk into the plastic. *Jump Stop also has
the metal guide come around from the back of the seattube.
http://www.jensonusa.com/store/produ...Jump+Start+Cha...
Photo in question.
http://www.cyclingnews.com/road/2009.../tech.php?id=/...

Russel, you're right.
Uncannily similar, a Jump Stop analogue?
--
Andrew Muzi
* www.yellowjersey.org/
* Open every day since 1 April, 1971- Hide quoted text -

- Show quoted text -

I'd guess its homemade by the shop mechanic, for some reason. Not
sure why someone would make one of these from scratch when you can
just buy them for $10 on the internet.

In my case, the commercial ones I've seen won't fit my bike. So I have
a piece of hard foam ziptied to the seat tube. But I'd like something
a little less prone to collecting dirt.

On Feb 18, 4:13*pm, John Forrest Tomlinson
wrote:
On Wed, 18 Feb 2009 06:49:38 -0800 (PST), "
wrote:

I'd guess its homemade by the shop mechanic, for some reason. *Not
sure why someone would make one of these from scratch when you can
just buy them for $10 on the internet. *

In my case, the commercial ones I've seen won't fit my bike. So I have
a piece of hard foam ziptied to the seat tube. But I'd like something
a little less prone to collecting dirt.

The N Gear Jump Stop uses a plastic collar and
metal chain guard - as distinct from the Third Eye
thingy which uses a metal hose clamp and plastic
chain guard. The plastic collar is probably a little
more deformable, and/or you could carve away
some of it. If I was trying to fit one to your bike, I might
make a shim from old inner tube that was half the
height of the collar, so it reduced the diameter at
the top but not the bottom of the collar. Also, if you
write to N-Gear, you get an answer from Nick, the
main guy. He's quite helpful.
http://www.gvtc.com/~ngear/

But anyway, maybe that won't work. The wire
chain guard that is clamped by the derailleur bolt
looks almost like one could be made from an
old spoke, though I'm not sure it would be stiff
enough. roadbikerider.com says to use 1/8" steel
rod, which is certainly cheap enough - tricky part
will be getting the FD clamp bolt to press on
enough of the rod to hold it. You may need a
washer and a longer bolt.

Ben