track fork on road bike w/ road bike geom.?

I'm working on converting a road bike to a entry-level track bike.
Will a track fork work well on a bike with road-bike geometry? Will it
make a difference in the handling (i.e. handle better on track)? Or
should I leave the perfectly fine road forks on it?

Thanks.

On Fri, 26 Dec 2003 06:35:55 +0000, JB wrote:

I'm working on converting a road bike to a entry-level track bike. Will a
track fork work well on a bike with road-bike geometry? Will it make a
difference in the handling (i.e. handle better on track)? Or should I
leave the perfectly fine road forks on it?

There are some concerns here. The track fork may be shorter, as well as
having less rake, than the road fork you are replacing it with. That will
throw off the handling of the bike.

What's wrong with the fork you have? If you have the money to replace the
fork, why not look into a real track frame? Some of them are pretty
inexpensive.

--

David L. Johnson

__o | "Business!" cried the Ghost. "Mankind was my business. The
_`\(,_ | common welfare was my business; charity, mercy, forbearance,
(_)/ (_) | and benevolence, were, all, my business. The dealings of my
trade were but a drop of water in the comprehensive ocean of my
business!" --Dickens, "A Christmas Carol"

JB wrote:

I'm working on converting a road bike to a entry-level track bike.
Will a track fork work well on a bike with road-bike geometry? Will it
make a difference in the handling (i.e. handle better on track)? Or
should I leave the perfectly fine road forks on it?

I'd just leave the road forks on it. Then you can always fit a front
brake [1] and play with it on the road when you can't get to the track.
Some tracks may only allow "proper" track bikes even though you've
removed the brakes and gears from your road bike!

[1] you may find it easier to have a spare bar/stem combo for the road
with the brake lever and brake attached, as otherwise you'll have to
leave the track bars untaped, or fit the lever over the tape (ugh). If
you're doing this, pursuit-style "cow horns" are best as you get
somewhere to rest your non-braking hand.

JB wrote:
I'm working on converting a road bike to a entry-level track bike.
Will a track fork work well on a bike with road-bike geometry? Will it
make a difference in the handling (i.e. handle better on track)? Or
should I leave the perfectly fine road forks on it?

Handling will vary when you change the height ( axle to
crown race), or the rake. Sure, you can do a drawing to
predict that change, but generally, if it handles well,
leave it alone. Round and oval blades behave the same for
all practical purposes.

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

A Muzi wrote in
:

JB wrote:
I'm working on converting a road bike to a entry-level track bike.
Will a track fork work well on a bike with road-bike geometry? Will it
make a difference in the handling (i.e. handle better on track)? Or
should I leave the perfectly fine road forks on it?

Handling will vary when you change the height ( axle to
crown race), or the rake. Sure, you can do a drawing to
predict that change, but generally, if it handles well,
leave it alone. Round and oval blades behave the same for
all practical purposes.


The issue here is not the difference between oval and round fork blades.
The intent of the oval blades is to provide the fork strength needed to
off set braking loads. The issue is trail. A "standard" road front end
is a 74 degree head angle and 4.0 fork rake resulting in a trail of about
56. A "standard" track bike uses a 75 degree head tube with 3.0 fork
rake resulting in a trail of about 66. The higher the trail measurement
the more stable or slower the handling. Or IOW, a track bike needs and
should be harder to turn than a road bike since there is no cornering
involved and stability is much more important.

The conversion of a road frame to a track specific frame (in terms of
geometry) can be done if the fork is selected to produce a trail in the
mid-50s and fork blade length is used to maintain the head angle. It's
not a simple matter of swapping forks because I doubt you'll find a fork
off the shelf that will produce the correct trail. The money spent on a
custom fork would be much better spent on a good used track bike/frame.

Of course there is also the problem of using road rear drop outs but
that's another thread. Best to locate a good used track frame or
purchase one new. I also recommend staying away from many mass produced
inexpensive track frames because most are simply road frames with track
drops outs (to save the manufacturers tooling costs).

ALF

On 26 Dec 2003 06:35:55 -0800, (JB) wrote:

I'm working on converting a road bike to a entry-level track bike.
Will a track fork work well on a bike with road-bike geometry? Will it
make a difference in the handling (i.e. handle better on track)? Or
should I leave the perfectly fine road forks on it?

Thanks.

Everything is rideable. Might work. If you have a fork, try it!

1. The shorter track fork should decrease the trail, and increase head
angle.
2. The decrease in fork rake should increase the trail.

A. As far as trail is concerned, the two effects tend to cancel. A
little trig could tell you by how much.
B. As far as head angle is concerned, the change is beneficial.

I know from personal experience that one case of the opposite
combination didn't work well. A Marinoni with a steel replacement road
fork became unstable around (my) top speed. Too much fork rake = too
little trail = instability.

JB wrote:

I'm working on converting a road bike to a entry-level track bike.
Will a track fork work well on a bike with road-bike geometry? Will it
make a difference in the handling (i.e. handle better on track)? Or
should I leave the perfectly fine road forks on it?

Andy Muzi replied:

Handling will vary when you change the height ( axle to
crown race), or the rake. Sure, you can do a drawing to
predict that change, but generally, if it handles well,
leave it alone. Round and oval blades behave the same for
all practical purposes.

Al Frost wrote:

The issue here is not the difference between oval and round fork blades.
The intent of the oval blades is to provide the fork strength needed to
off set braking loads. The issue is trail. A "standard" road front end
is a 74 degree head angle and 4.0 fork rake resulting in a trail of about
56. A "standard" track bike uses a 75 degree head tube with 3.0 fork
rake resulting in a trail of about 66. The higher the trail measurement
the more stable or slower the handling. Or IOW, a track bike needs and
should be harder to turn than a road bike since there is no cornering
involved and stability is much more important.

More important than trail is the issue of pedal clearance. Track forks
tend to be considerably shorter than road forks, which will lower the
front end, and also lower the bottom bracket (which may already be on
the low side for velodrome use.)

The conversion of a road frame to a track specific frame (in terms of
geometry) can be done if the fork is selected to produce a trail in the
mid-50s and fork blade length is used to maintain the head angle. It's
not a simple matter of swapping forks because I doubt you'll find a fork
off the shelf that will produce the correct trail. The money spent on a
custom fork would be much better spent on a good used track bike/frame.

Replacing the fork will do nothing to improve the handling of the frame,
nor will it make it a whit faster. Keep the original fork or buy a
track frame.

Of course there is also the problem of using road rear drop outs but
that's another thread.

That's an imaginary "problem."

Sheldon "Keep The Fork The Frame Was Designed For" Brown
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