Chain tensioner below cranks?

Tom Reynolds writes:

http://www.velonews.com/news/fea/7370.0.html

Quoted message said:

Scroll about halfway down the page to the only picture associated
with this article. If you click on the image to view a larger
version you can see that there is some sort of chain tensioner
device located below his chainring. Any idea what that is all
about?

You'll notice that this bicycle is from the days before the derailleur
and used a chain tensioner to make up for moving to a different rear
sprocket, which is done either manually or by a small forked guide
that moves the chain. You'll also notice these wheels have wing nuts
rather than QR's with skewers. This is old stuff, but it was still
around till about ten years after WWII in spite of emerging designs.

Jobst Brandt
[email hidden]

email hidden said:

Check out this picture on the VeloNews website:
http://www.velonews.com/news/fea/7370.0.html

Scroll about halfway down the page to the only picture associated with
this article. If you click on the image to view a larger version you
can see that there is some sort of chain tensioner device located below
his chainring. Any idea what that is all about?

Tom

Dear Tom,

Here's a direct link to the enlarged picture:

http://www.velonews.com/images/news/7370.9886.f.jpg

The text suggests a date of 1942, but the picture could be
from the 1930's.

Since there are two brake cables and levers and front and
rear calipers are visible, I'm guessing that the bike has a
freewheel mechanism (not a fixie), but the rear hub looks
like single gear, not an internal multi-speed hub--no
shifters are visible, and that chain tensioner wouldn't be
happy with a derailleur.

The text suggests a road race from one city to the next. I
can't tell for sure, but it looks as if he was using
butterfly axle nuts, suggesting an interest in quick-change.
Yet there seems to be no tool bag, no water bottle, no spare
tire--there might be a pump on the seat tube, but as usual
the rider's leg obscures that area.

So he's riding a bike with a single gear, two brakes, and a
snowplow chain tensioner . . . and what's that small dark
thing behind the heel of his left shoe, which might be on
the chainstay on the left side of the bike, or something
guiding the lower run of the chain on the other side?

I know that I've seen such chain tensioners, but I can't
find any pictures. Possibly in Berto's "Dancing Chain"?

With luck, someone who knows about that era will clear
things up.

Carl Fogel

Carl Fogel writes:

http://www.velonews.com/news/fea/7370.0.html

Quoted message said:

Quoted message said:

Scroll about halfway down the page to the only picture associated
with this article. If you click on the image to view a larger
version you can see that there is some sort of chain tensioner
device located below his chainring. Any idea what that is all
about?

Quoted message said:

Here's a direct link to the enlarged picture:

http://www.velonews.com/images/news/7370.9886.f.jpg

Quoted message said:

The text suggests a date of 1942, but the picture could be
from the 1930's.

Quoted message said:

Since there are two brake cables and levers and front and rear
calipers are visible, I'm guessing that the bike has a freewheel
mechanism (not a fixie), but the rear hub looks like single gear,
not an internal multi-speed hub--no shifters are visible, and that
chain tensioner wouldn't be happy with a derailleur.

You needn't guess, riding with a chain tensioner or for that matter a
derailleur, on a fixed gear doesn't work well when backpedaling.

Quoted message said:

The text suggests a road race from one city to the next. I can't
tell for sure, but it looks as if he was using butterfly axle nuts,
suggesting an interest in quick-change. Yet there seems to be no
tool bag, no water bottle, no spare tire--there might be a pump on
the seat tube, but as usual the rider's leg obscures that area.

Quoted message said:

So he's riding a bike with a single gear, two brakes, and a
snowplow chain tensioner . . . and what's that small dark
thing behind the heel of his left shoe, which might be on
the chainstay on the left side of the bike, or something
guiding the lower run of the chain on the other side?

He's riding a bicycle with probably a three/four-speed freewheel
before the reliable derailleur was around. There are such bicycles
around here in collections and I saw people riding that equipment
years ago.

Quoted message said:

I know that I've seen such chain tensioners, but I can't find any
pictures. Possibly in Berto's "Dancing Chain"?

Quoted message said:

With luck, someone who knows about that era will clear things up.

Oh how lucky!

Jobst Brandt
[email hidden]

Quoth Carl Fogel;

Quoted message said:

Here's a direct link to the enlarged picture:

http://www.velonews.com/images/news/7370.9886.f.jpg

The text suggests a date of 1942, but the picture could be
from the 1930's.

Since there are two brake cables and levers and front and
rear calipers are visible, I'm guessing that the bike has a
freewheel mechanism (not a fixie), but the rear hub looks
like single gear, not an internal multi-speed hub--no
shifters are visible, and that chain tensioner wouldn't be
happy with a derailleur.

Actually, it is a derailer, an early type called an "Osgear."

You can see photos of one of these on an old Bianchi at:

http://sheldonbrown.org/larz2000/osgear.htm
http://sheldonbrown.org/larz2000/osgearquarter.htm
http://sheldonbrown.org/larz2000/osgearside.htm

The tensioner was adjusted by hand. To shift gears, you would loosen
the tensioner, then operate the little flipper gadgets on top of the
chainstay while backpedaling until the chain was on the desired sprocket
of the 3-speed freewheel. Then you'd re-tighten the chain tensioner and
start pedaling forward again.

The version shown in the old racing photo is apparently a variant
version with the flippers on the bottom of the chainstay, so you could
shift while pedaling (very gently) forward.

Sheldon "Before My Time" Brown
+-------------------------------------------+
| Never do today what you can do tomorrow. |
| Something may occur to make you regret |
| your premature action. --Aaron Burr |
+-------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

"Sheldon Brown" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

(snippp!!!)

Just have a look here:

http://www.localhistory.scit.wlv.ac.uk/Museum/Transport/bicycles/Olympic.htm

There was a line of Stallard bicycles back in forties with Poland related
name like Zakopane, Wroclaw etc. The bike in question is one of them.

Cheers,

Tomek Li

Quoted message said:

You'll also notice these wheels have wing nuts
rather than QR's with skewers. This is old stuff, but it was still
around till about ten years after WWII in spite of emerging designs.

Someone tried to resurrect wingnuts a few years ago, during the lightweight
mountain bike craze. They were big nylon wingnuts, very lightweight. They
seemed fine as long as you were using vertical dropouts, and a rigid. IIRC,
someone tested the clamping force, and they were better than many of the QR
skewers on the market -- FWIW.

Matt O.

Sheldon Brown said:

Quoth Carl Fogel;

Quoted message said:

Here's a direct link to the enlarged picture:

http://www.velonews.com/images/news/7370.9886.f.jpg

The text suggests a date of 1942, but the picture could be
from the 1930's.

Since there are two brake cables and levers and front and
rear calipers are visible, I'm guessing that the bike has a
freewheel mechanism (not a fixie), but the rear hub looks
like single gear, not an internal multi-speed hub--no
shifters are visible, and that chain tensioner wouldn't be
happy with a derailleur.

Actually, it is a derailer, an early type called an "Osgear."

You can see photos of one of these on an old Bianchi at:

http://sheldonbrown.org/larz2000/osgear.htm
http://sheldonbrown.org/larz2000/osgearquarter.htm
http://sheldonbrown.org/larz2000/osgearside.htm

The tensioner was adjusted by hand. To shift gears, you would loosen
the tensioner, then operate the little flipper gadgets on top of the
chainstay while backpedaling until the chain was on the desired sprocket
of the 3-speed freewheel. Then you'd re-tighten the chain tensioner and
start pedaling forward again.

The version shown in the old racing photo is apparently a variant
version with the flippers on the bottom of the chainstay, so you could
shift while pedaling (very gently) forward.

Sheldon "Before My Time" Brown
+-------------------------------------------+
| Never do today what you can do tomorrow. |
| Something may occur to make you regret |
| your premature action. --Aaron Burr |
+-------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Dear Sheldon,

That explains it nicely--thanks for the links to your good
pictures.

I'd sorta-kinda wondered if there was very slightly larger
gear in the picture bcause the chain seems to be not quite
going over the top, but the angle is bad and the resolution
poor, so I have to admit that I still can't tell.

The flippers explain things nicely.

So now I gotta ask--in your pictures, what's the gear on the
other side for? I assume that it's intended to be used by
reversing, but it looks as if it's roughly the size of the
middle gear on the 3-gear cluster.

Am I wrong and it's actually much bigger or smaller?

Carl Fogel

Quoted message said:

Carl Fogel writes:

[snip]

Quoted message said:

Quoted message said:

With luck, someone who knows about that era will clear things up.

Oh how lucky!

Jobst Brandt
[email hidden]

Dear Jobst,

Actually, the luck seems to be much better over in Sheldon's
answer.

Enjoy his nice pictures and cheerful, interesting
explanation.

Carl Fogel

Quoted message said:

Check out this picture on the VeloNews website:
http://www.velonews.com/news/fea/7370.0.html

Quoted message said:

Scroll about halfway down the page to the only picture associated with
this article. If you click on the image to view a larger version you
can see that there is some sort of chain tensioner device located below
his chainring. Any idea what that is all about?

It's only contested with a fixed.

That picture is this system:
http://www.yellowjersey.org/eroica.html

it's a Vittoria changer, I believe.

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

A Muzi said:

Quoted message said:

Check out this picture on the VeloNews website:
http://www.velonews.com/news/fea/7370.0.html

Quoted message said:

Scroll about halfway down the page to the only picture associated

with

Quoted message said:

Quoted message said:

this article. If you click on the image to view a larger version

you

Quoted message said:

Quoted message said:

can see that there is some sort of chain tensioner device located

below

Quoted message said:

Quoted message said:

his chainring. Any idea what that is all about?

It's only contested with a fixed.

That picture is this system:
http://www.yellowjersey.org/eroica.html

it's a Vittoria changer, I believe.

Is that an integrated headset?

Quoted message said:

Quoted message said:

Quoted message said:

Check out this picture on the VeloNews website:
http://www.velonews.com/news/fea/7370.0.html

(am)>>http://www.yellowjersey.org/eroica.html

Quoted message said:

Is that an integrated headset?

In this style, the headlug is cupped and a bearing race with
a round back floats in that headlug. It self-aligns. When I
was young Dawes and Bianchi still used them
http://www.yellowjersey.org/photosfromthepast/BINKY66.JPG
for another example

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