Maybe bent fork? How to tell?

[John Smith]

Hello,

Recently I borrowed my wifes prized bike (nothing flash but she loves it) and maybe I was a *bit*
hard on it, I don't recall any nasty incidents but anyway, now it has some odd dynamics...

When I go into a turn with it, it seems to 'suck' itself further into the turn. I thought it might
be that the weight might have been all wrong set (seat right forwards to make up for excessively
long handlebar stem) but changing the handlebars to risers and shifting the seat back didn't help,
in fact, if you *lightly* push the bar on one side the bike steady drifts into a ever increasing
turn. Its better at speed but still not nice!

The bike has an alloy ridgid fork on alloy frame (pinewood x90). About 4" handlebar stem. Flat or DH
riser bars.

I am wondering if I have bent the fork backwards? It looks a little bit backwards to the eye but
(being nervous about a sick fork) I took it out, cleaned it all up and cerfully inspected it. No
cracked paint, not stress marks, in fact it looked fine. Off the bike its flat from the steerer tube
down along the fork until the fork does its bend forward section.

Any ideas? If it a normal characteristic how do I fix it? My wife has made the odd comment that its
'weird' to ride now, and it looks like I may be in trouble soon ;-)

Cheers!!

Hamish

 

[Serg]

maybe a bad head set? have u checked it holding the front wheel off the ground and turning the
hadlebar right and left? it should be smooth with no grinding and such.

"John Smith" <[email protected]> wrote in message news:[email protected]...
> Hello,
>
> Recently I borrowed my wifes prized bike (nothing flash but she loves it) and maybe I was a *bit*
> hard on it, I don't recall any nasty incidents but anyway, now it has some odd dynamics...
>
> When I go into a turn with it, it seems to 'suck' itself further into the turn. I thought it might
> be that the weight might have been all wrong set (seat right forwards to make up for excessively
> long handlebar stem) but changing the handlebars to risers and shifting the seat back didn't help,
in
> fact, if you *lightly* push the bar on one side the bike steady drifts
into
> a ever increasing turn. Its better at speed but still not nice!
>
> The bike has an alloy ridgid fork on alloy frame (pinewood x90). About 4" handlebar stem. Flat or
> DH riser bars.
>
> I am wondering if I have bent the fork backwards? It looks a little bit backwards to the eye but
> (being nervous about a sick fork) I took it out, cleaned it all up and cerfully inspected it. No
> cracked paint, not stress marks, in fact it looked fine. Off the bike its flat from the steerer
tube
> down along the fork until the fork does its bend forward section.
>
> Any ideas? If it a normal characteristic how do I fix it? My wife has
made
> the odd comment that its 'weird' to ride now, and it looks like I may be
in
> trouble soon ;-)
>
> Cheers!!
>
> Hamish

 

[John Smith]

Hi Serg,

Thanks for the reply, yeah, I checked that and its ok, really smooth and bearing all nice and
shiney, new grease etc, what I'm wondering is how much tolerance does the bikes handling have to a
slight change, say a shift backwards of 1/2" (roughly 1cm)?

/hamish

"serg" <[email protected]> wrote in message news:[email protected]...
> maybe a bad head set? have u checked it holding the front wheel off the ground and turning the
> hadlebar right and left? it should be smooth with no grinding and such.
>
> "John Smith" <[email protected]> wrote in message news:[email protected]...
> > Hello,
> >
> > Recently I borrowed my wifes prized bike (nothing flash but she loves
it)
> > and maybe I was a *bit* hard on it, I don't recall any nasty incidents
but
> > anyway, now it has some odd dynamics...
> >
> > When I go into a turn with it, it seems to 'suck' itself further into
the
> > turn. I thought it might be that the weight might have been all wrong
set
> > (seat right forwards to make up for excessively long handlebar stem) but changing the handlebars
> > to risers and shifting the seat back didn't
help,
> in
> > fact, if you *lightly* push the bar on one side the bike steady drifts
> into
> > a ever increasing turn. Its better at speed but still not nice!
> >
> > The bike has an alloy ridgid fork on alloy frame (pinewood x90). About
4"
> > handlebar stem. Flat or DH riser bars.
> >
> > I am wondering if I have bent the fork backwards? It looks a little bit backwards to the eye but
> > (being nervous about a sick fork) I took it
out,
> > cleaned it all up and cerfully inspected it. No cracked paint, not
stress
> > marks, in fact it looked fine. Off the bike its flat from the steerer
> tube
> > down along the fork until the fork does its bend forward section.
> >
> > Any ideas? If it a normal characteristic how do I fix it? My wife has
> made
> > the odd comment that its 'weird' to ride now, and it looks like I may be
> in
> > trouble soon ;-)
> >
> > Cheers!!
> >
> > Hamish
> >
>

 

[Werehatrack]

On Sat, 4 Oct 2003 19:30:33 +0200, "John Smith" <[email protected]> may have said:

>Hi Serg,
>
>Thanks for the reply, yeah, I checked that and its ok, really smooth and bearing all nice and
>shiney, new grease etc, what I'm wondering is how much tolerance does the bikes handling have to a
>slight change, say a shift backwards of 1/2" (roughly 1cm)?

If the fork is bent, it's probably not bent evenly. There's a tool to check for this; the lbs may
have it. It bolts to each fork tip independently; if the two bits of the tool don't line up, the
fork's bent.

See if the bike's manufacturer gives a spec for head tube angleon that model, and use a protractor
with a level to check it; if the angle is farther from vertical than it should be, then you may well
have bent the forks back a bit.

--
My email address is antispammed; pull WEEDS if replying via e-mail. Yes, I have a killfile. If I
don't respond to something, it's also possible that I'm busy.

 

[Tj Poseno]

Check if the frame, may be bent also, I have a road bike that does the same thing, if i let go of
the bars, it turns, so i cant ride no handed.

Supposibly thats whats wrong with my bike, I did a couple jumps with
it. (Its was all I had)

This is why I never ride others bikes, I always ay, oh, this bike can do it... OH SH@#, that dont
look good. So I stay off other peoples bikes.

 

[Traveller V.116]

[email protected] (TJ Poseno) wrote in news:[email protected]:

> Check if the frame, may be bent also, I have a road bike that does the same thing, if i let go of
> the bars, it turns, so i cant ride no handed.
>
> Supposibly thats whats wrong with my bike, I did a couple jumps with
> it. (Its was all I had)
>
> This is why I never ride others bikes, I always ay, oh, this bike can do it... OH SH@#, that dont
> look good. So I stay off other peoples bikes.

You can also check real wheel alignment. My bike's steering went wacko once; a quick check showed
the rear wheel off-center in the dropouts, cause an axle nut had worked loose.

 

[Pete Biggs]

Try riding with no hands (or with just a light touch on the bars with fingertips). If everything
else is ok and bike either consistently steers to one side or "auto-centers" more than normal then
forks are probably damaged.

A frame builder may be able to repair them but also consider new forks.

~PB

 

[Alex Rodriguez]

In article <[email protected]>, [email protected] says...
>Recently I borrowed my wifes prized bike (nothing flash but she loves it) and maybe I was a *bit*
>hard on it, I don't recall any nasty incidents but anyway, now it has some odd dynamics... When I
>go into a turn with it, it seems to 'suck' itself further into the turn. I thought it might be that
>the weight might have been all wrong set (seat right forwards to make up for excessively long
>handlebar stem) but changing the handlebars to risers and shifting the seat back didn't help, in
>fact, if you *lightly* push the bar on one side the bike steady drifts into a ever increasing turn.
>Its better at speed but still not nice! The bike has an alloy ridgid fork on alloy frame (pinewood
>x90). About 4" handlebar stem. Flat or DH riser bars. I am wondering if I have bent the fork
>backwards? It looks a little bit backwards to the eye but (being nervous about a sick fork) I took
>it out, cleaned it all up and cerfully inspected it. No cracked paint, not stress marks, in fact it
>looked fine. Off the bike its flat from the steerer tube down along the fork until the fork does
>its bend forward section. Any ideas? If it a normal characteristic how do I fix it? My wife has
>made the odd comment that its 'weird' to ride now, and it looks like I may be in trouble soon ;-)

Check the head tube /downtube junction. If it is wrinkled, then the damage is to the frame,
not the fork.
---------------
Alex

 

[A Muzi]

> In article <[email protected]>, [email protected] says...
>
>>Recently I borrowed my wifes prized bike (nothing flash but she loves it) and maybe I was a *bit*
>>hard on it, I don't recall any nasty incidents but anyway, now it has some odd dynamics... When I
>>go into a turn with it, it seems to 'suck' itself further into the turn. I thought it might be
>>that the weight might have been all wrong set (seat right forwards to make up for excessively long
>>handlebar stem) but changing the handlebars to risers and shifting the seat back didn't help, in
>>fact, if you *lightly* push the bar on one side the bike steady drifts into a ever increasing
>>turn. Its better at speed but still not nice! The bike has an alloy ridgid fork on alloy frame
>>(pinewood x90). About 4" handlebar stem. Flat or DH riser bars. I am wondering if I have bent the
>>fork backwards? It looks a little bit backwards to the eye but (being nervous about a sick fork) I
>>took it out, cleaned it all up and cerfully inspected it. No cracked paint, not stress marks, in
>>fact it looked fine. Off the bike its flat from the steerer tube down along the fork until the
>>fork does its bend forward section. Any ideas? If it a normal characteristic how do I fix it? My
>>wife has made the odd comment that its 'weird' to ride now, and it looks like I may be in trouble
>>soon ;-)

Alex Rodriguez wrote:
> Check the head tube /downtube junction. If it is wrinkled, then the damage is to the frame, not
> the fork.

Does it look like this perhaps?

http://www.yellowjersey.org/photosfromthepast/BRKNDREK.JPG

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