A few fixed gear questions.

A few questions:

1. How tight should the chain be on a fixed gear? I try to push the
rear wheel back as hard as I can into the dropout but when I do a
trackstand, I can still feel the slack in the chain when I switch from
forward to backward pressure. The chain looks perfectly taut but
certaintly does not feel so.

2. I ride in NYC where there are thousands of road obstacles (potholes,
manhole covers, etc.) and I'm finding the ride to be extremely harsh.
Any suggestions (e.g. a good fixed gear saddle)?

--
Will Fisher

"Will Fisher" wrote:

A few questions:

1. How tight should the chain be on a fixed gear? I try to push the
rear wheel back as hard as I can into the dropout but when I do a
trackstand, I can still feel the slack in the chain when I switch from
forward to backward pressure. The chain looks perfectly taut but
certaintly does not feel so.

Observation of your drivetrain while turning the pedals by hand will
make it obvious that the chain is not uniformly tight, due to small
eccentricity of either sprocket. Find the tightest spot and adjust the
axle position so that there is just a little (less than 0.5 inch)
vertical movement of the chain.

Do not attempt to make the chain as tight as you can. This will mean
that the chain will be even tighter at some point in the rotation and
that will lead to premature bearing failure.

If you like to have no slack in the chain, a tensioner will give the
closest approximation. But it does take away from the cool minimalism
of a fixie.

2. I ride in NYC where there are thousands of road obstacles (potholes,
manhole covers, etc.) and I'm finding the ride to be extremely harsh.
Any suggestions (e.g. a good fixed gear saddle)?

Fatter tires will make a BIG difference. If you are riding 23mm tires
now, try a pair of 28s if you have the clearance.

If your bike is a true track frame, it's gonna be harsh on the road, as
it is designed for a smooth track.

Saddles? A highly personal decision. A big ol' sprung saddle might
help with your ass, but not your hands, and such a saddle would be
offensive to my sense of taste on a fixie.

--
Ted Bennett
Portland, OR

I'll take that tire suggestion into consideration. Too bad my rims will
look a little too small for 28s but if it makes the ride easier,
anything.

I agree with you on that saddle aesthetics point. I considered a brooks
but none of the models would fit the slick look of my fixie. I'm
thinking Selle Italia Flite but that's because I've heard such good
reviews of it, not because I've tried it personally. Oh well.

Will Fisher wrote:

I'll take that tire suggestion into consideration. Too bad my rims will
look a little too small for 28s but if it makes the ride easier,
anything.

I don't think there are rims so narrow that using a 28-millimeter tyre
would be a problem. I know people running 40-millimeter studded tyres on
narrow road rims on the cyclocross bikes without problems, although
that might be pushing the limit. Here's a compatibility table:

http://www.sheldonbrown.com/tire-sizing.html#width

As it says below the table, people commonly exceed these recommendations
without problems. I think in your case, running 28-millimeter tyres on a
narrow rim should be just fine unless you use unusually low pressures.

I agree with you on that saddle aesthetics point. I considered a brooks
but none of the models would fit the slick look of my fixie. I'm
thinking Selle Italia Flite but that's because I've heard such good
reviews of it, not because I've tried it personally. Oh well.

The Flite works well for many people, but not for all. It's quite
expensive, but otherwise I think it's a good starting point if you
absolutely don't know what might be good for you.

-as

Ted wrote:

If you like to have no slack in the chain, a tensioner will give the
closest approximation. But it does take away from the cool minimalism
of a fixie.

I know it's bad form to respond to your own post, but the above is *bad*
advice for a fixie. A tensioner will fail spectacularly there.

Sorry about the brain fart.

--
Ted Bennett
Portland, OR

On 6 Jan 2005 18:58:16 -0800, "Will Fisher"
wrote:

A few questions:

1. How tight should the chain be on a fixed gear? I try to push the
rear wheel back as hard as I can into the dropout but when I do a
trackstand, I can still feel the slack in the chain when I switch from
forward to backward pressure. The chain looks perfectly taut but
certaintly does not feel so.

[snip]

Dear Will,

When you reverse tension, the chain roller taking the load
rolls back and forth in the bottom between two gear teeth,
no matter how hard you tension a chain.

Applying even a little tension causes the roller to ride up
just a tiny bit onto the face of the tooth.

To make things worse, this happens on both the front and
rear sprockets.

Notice that when you pedal, the top chain run goes taut and
the bottom run goes slack. When you start to brake and
reverse the tension, the bottom run goes goes taut and the
top run goes slack.

Sheldon Brown commented on fixie chain tensioning about a
year ago:

http://groups.google.co.uk/groups?q=...eldonbrown.com
or http://tinyurl.com/6m9tf

Carl Fogel

Carl assumes- When you reverse tension, the chain roller taking the load
rolls back and forth in the bottom between two gear teeth,
no matter how hard you tension a chain. BRBR

I would hope this gent doesn't have a 'roller' or anything else to help chain
tension. This is a fixie and with horizontal dropoiuts, no tension device
needed plus it can be ripped off spectacularly on a fixed gear.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Qui si parla Campagnolo wrote:

Carl assumes- When you reverse tension, the chain roller taking the load
rolls back and forth in the bottom between two gear teeth,
no matter how hard you tension a chain. BRBR

I would hope this gent doesn't have a 'roller' or anything else to help chain
tension. This is a fixie and with horizontal dropoiuts, no tension device
needed plus it can be ripped off spectacularly on a fixed gear.

"Roller" refers to the doughnut shaped part of the chain the fits around
the rivet/pin.

In the past, Carl Fogel has posted links to pictures of motorcycles with
chain tensioners - a motorcycle is effectively fixed-geared when the
clutch is engaged.

--
Tom Sherman - Near Rock Island

Tom- In the past, Carl Fogel has posted links to pictures of motorcycles with

chain tensioners - a motorcycle is effectively fixed-geared when the
clutch is engaged. BRBR

OK, install a tensioner on a bicycle fixed gear and ride it and let me know
what happens.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Peter Chisholm wrote:

[Dreadful AOL quoting format corrected]

Tom Sherman wrote:

In the past, Carl Fogel has posted links to pictures of motorcycles with
chain tensioners - a motorcycle is effectively fixed-geared when the
clutch is engaged.

OK, install a tensioner on a bicycle fixed gear and ride it and let me know
what happens.

I was merely attempting to preemptively post what Mr. Fogel's response
would be. The evidence [1] indicates that I did quite well.

[1]
http://groups-beta.google.com/group/rec.bicycles.tech/msg/85f8f73c79d7a014?dmode=source.

--
Tom Sherman - Near Rock Island