Fork spreading

[Keven]

Read through this: http://www.sheldonbrown.com/frame-spacing.html

But didn't see a reference to spreading the legs of the fork. I bought
a little bike for my son, an older Nishiki, and the fork seems to be
made for hubs that are smaller than the standard 100 mm. Perhaps they
are about 95 mm. How can I safely and effectively spread the fork so I
can fit a decent hub in there?

--keven.

 

[zen cycle]

Keven wrote:
> Read through this: http://www.sheldonbrown.com/frame-spacing.html
>
> But didn't see a reference to spreading the legs of the fork. I bought
> a little bike for my son, an older Nishiki, and the fork seems to be
> made for hubs that are smaller than the standard 100 mm. Perhaps they
> are about 95 mm. How can I safely and effectively spread the fork so I
> can fit a decent hub in there?
>
> --keven.

A) don't try it if it's not a steel fork.
B) Don't try it if you can't spread the legs by hand.

If it's a steel fork and you can pull the legs apart far enough to
insert a new by with hand/arm strength, it'll most likely be OK.
Otherwise, I'd get a new fork or a hub that's the right size. You don't
want to have your kid crash and lobotmize himself becasue of a fork
failure.

 

[[email protected]]

Keven Ruf writes:

> Read through this: http://www.sheldonbrown.com/frame-spacing.html

> But didn't see a reference to spreading the legs of the fork. I
> bought a little bike for my son, an older Nishiki, and the fork
> seems to be made for hubs that are smaller than the standard 100mm.
> Perhaps they are about 95mm. How can I safely and effectively
> spread the fork so I can fit a decent hub in there?

I don't know how long the fork legs are but if you know the width you
need and think you can do this carefully, do the following:

Lay the fork on its side, placing your foot on the blade next to the
floor at the fork crown. Grasp the end of the upper fork blade near
the dropout and bend it carefully outward measuring the progress until
you have half the required increase in spacing. Turn the fork over
and repeat to achieve the desired spacing.

Next using a hefty crescent wrench or stick one dropout in a vise,
bend them one at a time to be parallel to each other (about the
steering axis).

Job completed.

The method is crude but accurate enough to keep the fork on center.
Placing the foot near the fork crown allows one blade to be bent at a
time.

Jobst Brandt

 

[[email protected]]

Keven wrote:
> Read through this: http://www.sheldonbrown.com/frame-spacing.html
>
> But didn't see a reference to spreading the legs of the fork. I bought
> a little bike for my son, an older Nishiki, and the fork seems to be
> made for hubs that are smaller than the standard 100 mm. Perhaps they
> are about 95 mm. How can I safely and effectively spread the fork so I
> can fit a decent hub in there?
>
>

94mm was an older standard. You *may* be able to respace a 100mm hub to
94mm by removing or resizing any spacers between the cones and the
locknuts. I've done this in reverse (i.e., 94mm to 100mm) when an older
bike was fitted with a newer, 100mm, replacement fork.

 

[Mike Jacoubowsky]

> I don't know how long the fork legs are but if you know the width you
> need and think you can do this carefully, do the following:
>
> Lay the fork on its side, placing your foot on the blade next to the
> floor at the fork crown. Grasp the end of the upper fork blade near
> the dropout and bend it carefully outward measuring the progress until
> you have half the required increase in spacing. Turn the fork over
> and repeat to achieve the desired spacing.

The problem is getting familiar with where the yield point is. If you've
never done it before, the first time doesn't always go as planned. I'd
recommend experimenting first on a junky fork on a bike that's not long for
this world. After that, things go a lot easier, as you've gained the
confidence that comes from knowing you won't be destroying it.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

<[email protected]> wrote in message
news:[email protected]...
> Keven Ruf writes:
>
>> Read through this: http://www.sheldonbrown.com/frame-spacing.html
>
>> But didn't see a reference to spreading the legs of the fork. I
>> bought a little bike for my son, an older Nishiki, and the fork
>> seems to be made for hubs that are smaller than the standard 100mm.
>> Perhaps they are about 95mm. How can I safely and effectively
>> spread the fork so I can fit a decent hub in there?
>
> I don't know how long the fork legs are but if you know the width you
> need and think you can do this carefully, do the following:
>
> Lay the fork on its side, placing your foot on the blade next to the
> floor at the fork crown. Grasp the end of the upper fork blade near
> the dropout and bend it carefully outward measuring the progress until
> you have half the required increase in spacing. Turn the fork over
> and repeat to achieve the desired spacing.
>
> Next using a hefty crescent wrench or stick one dropout in a vise,
> bend them one at a time to be parallel to each other (about the
> steering axis).
>
> Job completed.
>
> The method is crude but accurate enough to keep the fork on center.
> Placing the foot near the fork crown allows one blade to be bent at a
> time.
>
> Jobst Brandt

 

[* * Chas]

"Mike Jacoubowsky" <[email protected]> wrote in message
news:[email protected]...
> > I don't know how long the fork legs are but if you know the width
you
> > need and think you can do this carefully, do the following:
> >
> > Lay the fork on its side, placing your foot on the blade next to the
> > floor at the fork crown. Grasp the end of the upper fork blade near
> > the dropout and bend it carefully outward measuring the progress
until
> > you have half the required increase in spacing. Turn the fork over
> > and repeat to achieve the desired spacing.
>
> The problem is getting familiar with where the yield point is. If
you've
> never done it before, the first time doesn't always go as planned. I'd
> recommend experimenting first on a junky fork on a bike that's not
long for
> this world. After that, things go a lot easier, as you've gained the
> confidence that comes from knowing you won't be destroying it.
>
> --Mike Jacoubowsky
> Chain Reaction Bicycles
> www.ChainReaction.com
> Redwood City & Los Altos, CA USA

You don't want to try that with an old Peugeot UO8 seamed tubing?? fork.
UO8s during the early 70s came with forks that were made from rolled
brazed sheet metal. It wasn't even seamed tubing. The slightest attempt
to bend the blades cause the brazed seam to split!

Chas.

 

[Dane Buson]

[email protected] wrote:
> Keven Ruf writes:
>
>> Read through this: http://www.sheldonbrown.com/frame-spacing.html
>
>> But didn't see a reference to spreading the legs of the fork. I
>> bought a little bike for my son, an older Nishiki, and the fork
>> seems to be made for hubs that are smaller than the standard 100mm.
>> Perhaps they are about 95mm. How can I safely and effectively
>> spread the fork so I can fit a decent hub in there?
>
> I don't know how long the fork legs are but if you know the width you
> need and think you can do this carefully, do the following:
>
> Lay the fork on its side, placing your foot on the blade next to the
> floor at the fork crown. Grasp the end of the upper fork blade near
> the dropout and bend it carefully outward measuring the progress until
> you have half the required increase in spacing. Turn the fork over
> and repeat to achieve the desired spacing.
>
> Next using a hefty crescent wrench or stick one dropout in a vise,
> bend them one at a time to be parallel to each other (about the
> steering axis).
>
> Job completed.
>
> The method is crude but accurate enough to keep the fork on center.
> Placing the foot near the fork crown allows one blade to be bent at a
> time.

I'm glad this thread showed up. I have a folder that the front was at
88mm. I have to say it was easier to set the spacing on the fork than
resetting the spacing on a frame. Now I can put a decent wheel on the
front.

I'm thinking the SA Dyno/Drum hub combination would be awfully nice.
Then I could get rid of the incredibly terrible ultra-long reach brakes.

--
Dane Buson - [email protected]
Claret is the liquor for boys; port for men; but he who aspires to be a hero
.... must drink brandy.
-- Samuel Johnson