Fork vibration

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

Quoted message said:

Bike is a new Trek 4900 with the Judy fork. I bought it for my wife,

she'll

Quoted message said:

rarely ride it. I just bought it for her so she could ride with me when

she

Quoted message said:

felt like it. She loves it, BTW, says it's the best bike she's ever been
on. She may ride a gravel road with it someday, other than that it'll be
strictly roads.

But tonight I've got my 225 lbs on this thing, and I'm coasting down a

nice

Quoted message said:

paved incline and begin leaning on the brakes to slow up a bit, more
pressure applied to the rear than the front, and I notice that the front
fork shudders every time I touch the brake.
I'm doing maybe 20mph. I don't experiment to verify, but I'm pretty

certain

Quoted message said:

that if I increase front braking pressure much things are going to get

scary

Quoted message said:

pretty quickly.

So, is this just a "Trek thing", or should I take it in to the LBS with

the

Quoted message said:

expectation that a properly adjusted Judy fork on a Trek 4900 won't behave
so badly.

Getting back into this whole bike thing is so cool, btw. I'm 42 and

haven't

Quoted message said:

ridden since I was 25.

Thanks for any input.

About this "vibration"...
Does it happen only at or over a high(er) speed like 20 mph?
Or does it happen at a slower speed?
Can you hear it too?
Can you feel it too?
Or can you just see it?

You know, the RS Judy fork these days is a very low end fork, I would check
it out but it might just be that flexy!

Check the headset by applying the front brake and rocking back and forth
while feeling around the hs cup for movement with you hand.

Any noises when you do this or apply the front brake (except for normal
brake pad sound - same as back brake) is bad!

Does it do that when you wife rides it? I assume she weighs less than you
so if it doesn't shudder your weight is just too much for it.

BTW you weight is on the upper range of what you could get springs for even
a higher end RS like the Psylo.

mikeg said:

Bike is a new Trek 4900 with the Judy fork. I bought it for my wife,
she'll rarely ride it. I just bought it for her so she could ride
with me when she felt like it. She loves it, BTW, says it's the best
bike she's ever been on. She may ride a gravel road with it someday,
other than that it'll be strictly roads.

But tonight I've got my 225 lbs on this thing, and I'm coasting down
a nice paved incline and begin leaning on the brakes to slow up a
bit, more pressure applied to the rear than the front, and I notice
that the front fork shudders every time I touch the brake.
I'm doing maybe 20mph. I don't experiment to verify, but I'm pretty
certain that if I increase front braking pressure much things are
going to get scary pretty quickly.

So, is this just a "Trek thing", or should I take it in to the LBS
with the expectation that a properly adjusted Judy fork on a Trek
4900 won't behave so badly.

Getting back into this whole bike thing is so cool, btw. I'm 42 and
haven't ridden since I was 25.

If the bike is set up properly for your wife, you should stay the heck off
it! (Unless, of course, she also weighs 225.)

Are these V-brakes or discs? Take it back to the shop, and tell 'em what
happened. They should check it out for free.

For the riding you say your wife will do, suspension is counter-productive.
Big fat tires are plenty cushy for roads and occasional gravel pathways.
(But since you've got it, don't set the shock super-soft, at least.)

Bill "random thoughts" S.

On 2004-07-11, mikeg penned:

Quoted message said:

Bike is a new Trek 4900 with the Judy fork. I bought it for my wife,
she'll rarely ride it. I just bought it for her so she could ride
with me when she felt like it. She loves it, BTW, says it's the best
bike she's ever been on. She may ride a gravel road with it someday,
other than that it'll be strictly roads.

But tonight I've got my 225 lbs on this thing, and I'm coasting down a
nice paved incline and begin leaning on the brakes to slow up a bit,
more pressure applied to the rear than the front, and I notice that
the front fork shudders every time I touch the brake. I'm doing maybe
20mph. I don't experiment to verify, but I'm pretty certain that if I
increase front braking pressure much things are going to get scary
pretty quickly.

You say that she loves it. Does *she* experience fork vibration when
*she* rides it?

If she's much lighter than you and the fork is set up for her weight, I
suppose all sorts of things could go wonky when you ride it.

Quoted message said:

So, is this just a "Trek thing", or should I take it in to the LBS
with the expectation that a properly adjusted Judy fork on a Trek 4900
won't behave so badly.

I never had fork vibration on my Trek. It sounds like either a "the
shock isn't set up for 225 pounds" thing or, possibly, a "this bike may
not have been set up well" thing.

--
monique

Quoted message said:

But tonight I've got my 225 lbs on this thing, and I'm coasting down
a nice paved incline and begin leaning on the brakes to slow up a
bit, more pressure applied to the rear than the front, and I notice
that the front fork shudders every time I touch the brake.

Your wheel is likely out of true. Spin it and see if it exhibits wobble at
the brake pads. If so, get it fixed at an LBS.

--
Phil, Squid-in-Training

mikeg said:

Bike is a new Trek 4900 with the Judy fork. I bought it for my wife, she'll
rarely ride it. I just bought it for her so she could ride with me when she
felt like it. She loves it, BTW, says it's the best bike she's ever been
on. She may ride a gravel road with it someday, other than that it'll be
strictly roads.

But tonight I've got my 225 lbs on this thing, and I'm coasting down a nice
paved incline and begin leaning on the brakes to slow up a bit, more
pressure applied to the rear than the front, and I notice that the front
fork shudders every time I touch the brake.
I'm doing maybe 20mph. I don't experiment to verify, but I'm pretty certain
that if I increase front braking pressure much things are going to get scary
pretty quickly.

So, is this just a "Trek thing", or should I take it in to the LBS with the
expectation that a properly adjusted Judy fork on a Trek 4900 won't behave
so badly.

Getting back into this whole bike thing is so cool, btw. I'm 42 and haven't
ridden since I was 25.

Thanks for any input.

The Judy is a horrid fork. Actually, Rock Shox should've called it
Gumby. I constantly had problems with mine rubbing on the brake rotor,
especially when turning. Eventually, I had it replaced with a much
better (non-Rock Shox) fork.

There might be other problems with the frame (??), but most likely it's
just the fork. You should have the shop take a look at it and try to
duplicate the problem.

--
Slacker

Quoted message said:

I suppose all sorts of things could go wonky when you ride it.

Yes! I'm not the only one that says "wonky!"
*high-five*
--
Phil, Squid-in-Training

On 2004-07-11, ZeeExSixAre penned:

Quoted message said:

Quoted message said:

I suppose all sorts of things could go wonky when you ride it.

Yes! I'm not the only one that says "wonky!" *high-five*

*grin*

It's entirely possible I picked it up from you, I suppose =)

--
monique

ZX6R says:

Quoted message said:

Yes! I'm not the only one that says "wonky!" *high-five*

I grew up with that one, but that was on the other side of the Puddle, where it
is pretty normal to use "wonky" to describe something. You've obviously been
watching too many BritComs. ;-)
OTOH, the Oxford Desk Dictionary (US edition) describes a "wonk" as a student
who studies too hard. So that can't really apply to you, either ;-P

Steve

I've had this problem with disc brakes on the same shock. I found the
problem to be dirty brakes. Cleaned the pads and rotor with brake cleaning
fluid, all is well.
Cheers
George

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

Quoted message said:

mikeg said:

Bike is a new Trek 4900 with the Judy fork. I bought it for my wife,

she'll

Quoted message said:

Quoted message said:

rarely ride it. I just bought it for her so she could ride with me when

she

Quoted message said:

Quoted message said:

felt like it. She loves it, BTW, says it's the best bike she's ever

been

Quoted message said:

Quoted message said:

on. She may ride a gravel road with it someday, other than that it'll

be

Quoted message said:

Quoted message said:

strictly roads.

But tonight I've got my 225 lbs on this thing, and I'm coasting down a

nice

Quoted message said:

Quoted message said:

paved incline and begin leaning on the brakes to slow up a bit, more
pressure applied to the rear than the front, and I notice that the front
fork shudders every time I touch the brake.
I'm doing maybe 20mph. I don't experiment to verify, but I'm pretty

certain

Quoted message said:

Quoted message said:

that if I increase front braking pressure much things are going to get

scary

Quoted message said:

Quoted message said:

pretty quickly.

So, is this just a "Trek thing", or should I take it in to the LBS with

the

Quoted message said:

Quoted message said:

expectation that a properly adjusted Judy fork on a Trek 4900 won't

behave

Quoted message said:

Quoted message said:

so badly.

Getting back into this whole bike thing is so cool, btw. I'm 42 and

haven't

Quoted message said:

Quoted message said:

ridden since I was 25.

Thanks for any input.

The Judy is a horrid fork. Actually, Rock Shox should've called it
Gumby. I constantly had problems with mine rubbing on the brake rotor,
especially when turning. Eventually, I had it replaced with a much
better (non-Rock Shox) fork.

There might be other problems with the frame (??), but most likely it's
just the fork. You should have the shop take a look at it and try to
duplicate the problem.

--
Slacker