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

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

"Will Fisher" writes:

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.

Chain doesn't need to be so tight, in fact it often causes binding
problems in the drivetrain.

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)?

Track bikes ride harsh because of the short wheelbase. Try a
different type of bike that's actually designed for riding on the
road, if a track bike is what you're riding.

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:

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)?

That sounds too tight.
You'll feel lash no matter what when you reverse direction.
http://www.yellowjersey.org/chainchk.html

You'll learn to lift your butt off the saddle. No saddle
will cushion a pothole with your full weight on it.

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

Will Fisher asked:

1. How tight should the chain be on a fixed gear?

Generally speaking, you can allow a little bit
of slack in the chain which will be visible
to the eye. Ideally, imo, the chain should
look pretty straight on top. If you get it
too tight you will know because the
drivetrain won't turn freely.

One way to do it is install the wheel
with the bike turned upside down, and
jam a big crescent wrench or other
suitable object between the frame and
the tire to crow-bar the wheel back
as you tighten the nuts.

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)?

It's not about the saddle. Remove yourself from
the saddle at least a little while traversing bad road
sections and your life will improve. Keep your arms
and legs bent and stay loose.

Also, micro-manage your line to avoid obstacles.

Tires: I wouldn't use any tires smaller than 25
in the city.

Robert

Will Fisher asked:
1. How tight should the chain be on a fixed gear?
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)?

R15757 wrote:
Generally speaking, you can allow a little bit
of slack in the chain which will be visible
to the eye. Ideally, imo, the chain should
look pretty straight on top. If you get it
too tight you will know because the
drivetrain won't turn freely.

One way to do it is install the wheel
with the bike turned upside down, and
jam a big crescent wrench or other
suitable object between the frame and
the tire to crow-bar the wheel back
as you tighten the nuts.


It's not about the saddle. Remove yourself from
the saddle at least a little while traversing bad road
sections and your life will improve. Keep your arms
and legs bent and stay loose.
Also, micro-manage your line to avoid obstacles.

Tires: I wouldn't use any tires smaller than 25
in the city.

Good saddle and tire advice but your chain is way too tight.
You're needlessly accelerating drivetrain wear.

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

Will- 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. BRBR

I say, chainwheels and rear hubs/cogs are not perfectly round. The chain will
go tight/loose as you pedal. The tightest part should have about 1/2 inch of
slack.

Will- 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)? BRBR

I say-fatter ties are a better solution, fat enough to fit into your frame.

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

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"