Fixed gearing help

Jai Ma said:

I
went today with the 42-20 freewheel setup and found it perfect for my 14
to 16 mph spin ride (mostly flat, some very short minor grades).
Pretending I had no coasting ability it seemed as if I would be
uncomfortably overspinning on downgrades I didn't even realize existed.

I would be surprised if you found it comfortable, let alone "perfect" to
go 14-16 mph in a gear that small, especially a fixed gear. I use a 42/17
on my commute (rolling terrain), and am quite comfortable with it. You
have to work on the hills, but that is part of the point. Take them as
fast as you can and you'll find them more comfortable.

Quoted message said:

Any opinions on what gear I should use for my purposes (with either a 39
or a 42 in front)?
Also if I go fixed/free and want the free to be around mid-fifty inches
how low could I go on the fixed side with horizontal droupouts that are
about 3cm? Could I use a 39-19 free and 39-16 fixed or a 42-20 free and
42-17 fixed, could I go even a gear lower for the fixed?

Lower? You mean a 42/18, which is a lower gear, or a 42/16? A 42/16 is
not so much of a spinning experience unless you push your speed up some.

Quoted message said:

Two other unrelated questions:
Is it unreasonable to only have a front brake when I use the freewheel?

Yes, it is unreasonable. Things go wrong. You do not want the only way
you can slow down to go wrong. That's what back brakes are for on geared
bikes, as a backup. On a fixie you can slow down with your legs if need
be, so the backup rear brake is less of a concern (I use one,though, since
I climb on the hoods, anyway). But with a freewheel you have no backup
without a rear brake.

Quoted message said:

(it felt comfortable to me)
What kind of tool do you use to take off a single speed freewheel? Is it
brand specific?

Yes, pretty much. But a lot of them use a large 4-prong tool.

--

David L. Johnson

__o | Accept risk. Accept responsibility. Put a lawyer out of
_`\(,_ | business.
(_)/ (_) |

Jai Ma said:

I'm putting together my first fixed. I've got a bike all set up (deraileurs
removed, inner front chainring and front brake only) except for the rear
wheel that still has the six speed freewheel on. The chain is pulled tight
and it aligns straight with the 20 tooth gear, so that's where it is for the
test. The chainring is a 42 tooth. I ride two very hard road rides
(geared) every week. For me, the other 4 rides per week (including
commuting) have to be easy spin 14 to 16 mph recovery rides. I went today
with the 42-20 freewheel setup and found it perfect for my 14 to 16 mph spin
ride (mostly flat, some very short minor grades). Pretending I had no
coasting ability it seemed as if I would be uncomfortably overspinning on
downgrades I didn't even realize existed.

I would think so, with such a low gear!

Quoted message said:

Any opinions on what gear I should use for my purposes (with either a 39 or
a 42 in front)?

If your primary purpose is to develop a wicked fast spin, low is good.
If your primary purpose is to have fun, generally the highest gear that
will let you climb your local hills is the best choice.

For me, in the rolling terrain of New England, this works out to about
42/15. For flat terrain I generally go with 42/14 (or 26/8 with 1" chain.)

Quoted message said:

Also if I go fixed/free and want the free to be around mid-fifty inches how
low could I go on the fixed side with horizontal droupouts that are about
3cm? Could I use a 39-19 free and 39-16 fixed or a 42-20 free and 42-17
fixed, could I go even a gear lower for the fixed?

Each tooth added/subtracted moves the axle 1/8".

Quoted message said:

Two other unrelated questions:
Is it unreasonable to only have a front brake when I use the freewheel? (it
felt comfortable to me)

The problem is that there's no back up system. If something goes wrong
with your front brake, or if your front tire blows at speed, you could
be in a bit of a pickle.

Quoted message said:

What kind of tool do you use to take off a single speed freewheel? Is it
brand specific?

Most of the decent-quality ones use the Park FR-6 4-prong puller.

See: http://sheldonbrown.com/harris/tools/freewheel.html

Sheldon "Fixed For Fun" Brown
+-------------------------------------------+
| Never tell people 'how' to do things. |
| Tell them 'what' to do and they will |
| surprise you with their ingenuity. |
| --General George S. Patton |
+-------------------------------------------+
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

"Jai Ma" <[email hidden]> wrote in message news:<[email hidden]>...
<some snippage>

Quoted message said:

I went today
with the 42-20 freewheel setup and found it perfect for my 14 to 16 mph spin
ride (mostly flat, some very short minor grades). Pretending I had no
coasting ability it seemed as if I would be uncomfortably overspinning on
downgrades I didn't even realize existed.

Spinning ability will increase as you ride more fixed miles. However,
you are running roughly 50-odd inches, which is a pretty low gearing
for general road use. FWIW, I find myself spinning along pretty good
with a ~74 inch gear setup on noticeable downhills. I'd be seriously
using the brakes with 50". (Northern California - there are hills
here).

Quoted message said:

Any opinions on what gear I should use for my purposes (with either a 39 or
a 42 in front)?
Also if I go fixed/free and want the free to be around mid-fifty inches how
low could I go on the fixed side with horizontal droupouts that are about
3cm? Could I use a 39-19 free and 39-16 fixed or a 42-20 free and 42-17
fixed, could I go even a gear lower for the fixed?

Higher? 42x15? Changing sizes of sprocket by a tooth should move the
axle 1/8" - That'll depend upon your dropout length if you want to
combine it with a 42X20FW.

Sounds like for what you are seeking, the 42X17 fixed/20FW is a nice
start. However, you'll have to "stay loose" on any downhills.

Quoted message said:

Two other unrelated questions:
Is it unreasonable to only have a front brake when I use the freewheel? (it
felt comfortable to me)

I wouldn't ride it that way if there were any kind of traffic or
downhills.

Quoted message said:

What kind of tool do you use to take off a single speed freewheel? Is it
brand specific?

It will be determined by the configuration of the freewheel (2 or 4
slots). Tool looks something like this:

http://www.parktool.com/tools/FR_2.shtml

Plus, you'll need a chain whip:

http://www.parktool.com/tools/SR_1.shtml

And, I'm sure you've found this already, but do read through this if
you haven't:

http://www.sheldonbrown.com/fixed.html

Hope that helps,

-- Jim

Jai Ma said:

I'm putting together my first fixed. I've got a bike all set up (deraileurs
removed, inner front chainring and front brake only) except for the rear
wheel that still has the six speed freewheel on. The chain is pulled tight
and it aligns straight with the 20 tooth gear, so that's where it is for the
test. The chainring is a 42 tooth. I ride two very hard road rides
(geared) every week. For me, the other 4 rides per week (including
commuting) have to be easy spin 14 to 16 mph recovery rides. I went today
with the 42-20 freewheel setup and found it perfect for my 14 to 16 mph spin
ride (mostly flat, some very short minor grades). Pretending I had no
coasting ability it seemed as if I would be uncomfortably overspinning on
downgrades I didn't even realize existed.

Any opinions on what gear I should use for my purposes (with either a 39 or
a 42 in front)?
Also if I go fixed/free and want the free to be around mid-fifty inches how
low could I go on the fixed side with horizontal droupouts that are about
3cm? Could I use a 39-19 free and 39-16 fixed or a 42-20 free and 42-17
fixed, could I go even a gear lower for the fixed?

Two other unrelated questions:
Is it unreasonable to only have a front brake when I use the freewheel? (it
felt comfortable to me)
What kind of tool do you use to take off a single speed freewheel? Is it
brand specific?

I find 70" (48 x 18 on a 700c wheel) the best compromise for general
riding, although I time trial on 48 x 14. It's a mistake to go too low:
even 48 x 18 is scary on steep downhills.

A single front brake is legal in the UK with a fixed wheel and is what I
use. You must be confident it is 100% reliable, and it will get a *lot*
more use than on a freewheel-equipped bike because you have to keep to a
maximum safe pedalling speed on descents. If you regularly ride down
long hills, leave the back brake on so you can alternate between the two
and avoid overheating problems.

"Jai Ma" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I'm putting together my first fixed.

Quoted message said:

I went today
with the 42-20 freewheel setup and found it perfect for my 14 to 16 mph spin
ride (mostly flat, some very short minor grades). Pretending I had no
coasting ability it seemed as if I would be uncomfortably overspinning on
downgrades I didn't even realize existed.

Any opinions on what gear I should use for my purposes (with either a 39 or
a 42 in front)?

I like a 42x15 for flattish/rolling routes.

Quoted message said:

Is it unreasonable to only have a front brake when I use the freewheel? (it
felt comfortable to me)

I prefer to have both brakes because I often ride the F-G in situations with
limited traction (rain/snow) and I prefer to distribute the braking when
traction is really bad (mostly snow/ice). It's also nice to use the rear for
controlling speeds on long descents ("drag" brake to keep cadence within
comfort zone) so that the heat load is shared by both rims.