How Did I Dent My BIke? Please Read and Suggest

[James Lynx]

Okay,

It's actually my girlfriend's bike. A Trek 4100 13 inch
bike. She was riding for an hour. We put it on the bike rack
on the car and I dropped her off at her place and drove back
to my place. After I took the bike off the rack I didn't
notice any dents. I rode it for about a couple of minutes.
Sure I'm taller and don't ride a 13 inch bike. My frame is
19 inch. I have a Fuji Discovery II but wanted to try her
bike. I got off and noticed a small dent about half the size
of a dime (please don't say a nickel!). Very small. Now mind
you before we put it on the car rack we didn't notice it and
I didn't notice it when I took it off the rack. It could
have been dented by the rack sure and I didn't notice it but
I think I would have noticed it because I did notice it
after I rode it. I am 200 LBS. Could my weight have caused a
small dent in the frame? It's the lower tube not the top
tube. Or do you think it's more likely loading it on the
bike rack would cause such a dent rather than me riding the
bike? Sure I'm 200 LBS but why should I be able to cause a
dent by my weight. How weak are these bikes? I know you
weren't there but I'm giving you the scenario and maybe you
can help with the likelyhood of different causes.

Thanks,

James

 

[Chuck W]

"James Lynx" <[email protected]> wrote in message
news:[email protected]...
> Okay,
>
> It's actually my girlfriend's bike. A Trek 4100 13 inch
> bike. She was riding for an hour. We put it on the bike
> rack on the car and I dropped her off at her place and
> drove back to my place. After I took the bike off the rack
> I didn't notice any dents. I rode it for about a couple of
> minutes. Sure I'm taller and don't ride a 13 inch bike. My
> frame is 19 inch. I have a Fuji Discovery II but wanted to
> try her bike. I got off and noticed a small dent about
> half the size of a dime (please don't say a nickel!). Very
> small. Now mind you before we put it on the car rack we
> didn't notice it and I didn't notice it when I took it off
> the rack. It could have been dented by the rack sure and I
> didn't notice it but I think I would have noticed it
> because I did notice it after I rode it. I am 200 LBS.
> Could my weight have caused a small dent in the frame?
> It's the lower tube not the top tube. Or do you think it's
> more likely loading it on the bike rack would cause such a
> dent rather than me riding the bike? Sure I'm 200 LBS but
> why should I be able to cause a dent by my weight. How
> weak are these bikes? I know you weren't there but I'm
> giving you the scenario and maybe you can help with the
> likelyhood of different causes.
>
>
>
>
> Thanks,
>
>
>
> James

That really depends on exactly where the dent is on the down
tube, and where else you've inspected for damage. If your
weight caused the frame to begin buckling (which is hard to
imagine just riding around a bit with no crazy stuff
involved), then the top tube should have visible signs of
the same type of buckling as well, or there should be cracks
forming at the welds between the frame members in one or
more places.

If you don't see any of that, I'd say you just dinged it on
something.

-Chuck W

 

[S O R N I]

James Lynx wrote:
> Okay,
>
> It's actually my girlfriend's bike. A Trek 4100 13 inch
> bike. She was riding for an hour. We put it on the bike
> rack on the car and I dropped her off at her place and
> drove back to my place. After I took the bike off the rack
> I didn't notice any dents. I rode it for about a couple of
> minutes. Sure I'm taller and don't ride a 13 inch bike. My
> frame is 19 inch. I have a Fuji Discovery II but wanted to
> try her bike. I got off and noticed a small dent about
> half the size of a dime (please don't say a nickel!). Very
> small. Now mind you before we put it on the car rack we
> didn't notice it and I didn't notice it when I took it off
> the rack. It could have been dented by the rack sure and I
> didn't notice it but I think I would have noticed it
> because I did notice it after I rode it. I am 200 LBS.
> Could my weight have caused a small dent in the frame?
> It's the lower tube not the top tube. Or do you think it's
> more likely loading it on the bike rack would cause such a
> dent rather than me riding the bike? Sure I'm 200 LBS but
> why should I be able to cause a dent by my weight. How
> weak are these bikes? I know you weren't there but I'm
> giving you the scenario and maybe you can help with the
> likelyhood of different causes.

What type of rack -- fork mount or one of those clamps that
hold the downtube?

Back in '96, a friend was putting my brand-new (well,
almost) Fisher Paragon up on his rack -- it was a Ford
Bronco II so I had to hand it up him -- and then I heard him
say, "Oh-oh". The friggin' clamp put a crimp in my downtube.

Rode it that way for a few years until the frame cracked
near the headtube/downtube junction (but not at a weld);
got it replaced under warranty and still (hardly ever)
ride it today.

Bill "ugly '98 black/yellow instead of the loud '99 yellow-
red scheme frame (original was a deep blue)" S.

 

[Matthew Paterso]

On Mon, 31 May 2004 20:14:37 -0700, James Lynx wrote:

> It's actually my girlfriend's bike.

Dude, your not getting any nookie for like a month!

--
Matt

Fear of a flat planet

 

[Pippen]

"James Lynx" <[email protected]> wrote in message
news:[email protected]...
> Okay,
>
> It's actually my girlfriend's bike. A Trek 4100 13 inch
> bike. She was riding for an hour. We put it on the bike
> rack on the car and I dropped her off at her place and
> drove back to my place. After I took the bike off the rack
> I didn't notice any dents. I rode it for about a couple of
> minutes. Sure I'm taller and don't ride a 13 inch bike. My
> frame is 19 inch. I have a Fuji Discovery II but wanted to
> try her bike. I got off and noticed a small dent about
> half the size of a dime (please don't say a nickel!). Very
> small. Now mind you before we put it on the car rack we
> didn't notice it and I didn't notice it when I took it off
> the rack. It could have been dented by the rack sure and I
> didn't notice it but I think I would have noticed it
> because I did notice it after I rode it. I am 200 LBS.
> Could my weight have caused a small dent in the frame?
> It's the lower tube not the top tube. Or do you think it's
> more likely loading it on the bike rack would cause such a
> dent rather than me riding the bike? Sure I'm 200 LBS but
> why should I be able to cause a dent by my weight. How
> weak are these bikes? I know you weren't there but I'm
> giving you the scenario and maybe you can help with the
> likelyhood of different causes.
>
>
>
>
> Thanks,
>
>
>
> James

My guess is that someone dented the down tube. My
assumptions are you rode it around the parking lot with out
running into anything with the front wheel.

Reason 1: The downtube has a elongation forces when only
riding the bike around while the top tube has compression
forces. Denting would be the first signs of a crumpling
effect caused by compression forces. I would expect to see
that on the top tube not on the down tube from you being to
heavy for the bike.

Reason 2: At that level of a bike I doubt that the wall
thinkness for the tube set is any different than that for
let's say a 19 inch bike. A smaller frame should be stonger
than a larger frame given the same thickness in the tube
set. Even if the tube set it double or triple butted the
smaller frame should be stronger.

Of couse if what you mean by "I rode it for about a
couple of minutes." means down a set of stairs with a
four foot wall at the end then yes you may have dented it
with your wieght...

-p

 

[James Lynx]

Pippen from what you and others describe I can be confident
that I did not dent the tube by my weight. I must have
dented it placing it on the bike rack.

For the above poster who asked what kind of rack it is.
Well, it's on the back of the mini van and you place the top
tubes over two individual arms so to speak. I'm new to the
whole bike rack thing so I don't even know proper names for
this stuff. I must have pushed the bottom tube into the rack
arm pretty hard or something. The bike will be fine because
it's a really small dent anyway. And yes only rode in the
parking lot a few minutes and rode on the street for a few
minutes. No jumping off of rocks or riding down stairs.

Thanks all for all the input here.

Thanks,

James

"Pippen" <[email protected]> wrote in message
news:<QC0vc.30182$js4.26893@attbi_s51>...
> "James Lynx" <[email protected]> wrote in message
> news:[email protected]...
> > Okay,
> >
> > It's actually my girlfriend's bike. A Trek 4100 13 inch
> > bike. She was riding for an hour. We put it on the bike
> > rack on the car and I dropped her off at her place and
> > drove back to my place. After I took the bike off the
> > rack I didn't notice any dents. I rode it for about a
> > couple of minutes. Sure I'm taller and don't ride a 13
> > inch bike. My frame is 19 inch. I have a Fuji Discovery
> > II but wanted to try her bike. I got off and noticed a
> > small dent about half the size of a dime (please don't
> > say a nickel!). Very small. Now mind you before we put
> > it on the car rack we didn't notice it and I didn't
> > notice it when I took it off the rack. It could have
> > been dented by the rack sure and I didn't notice it but
> > I think I would have noticed it because I did notice it
> > after I rode it. I am 200 LBS. Could my weight have
> > caused a small dent in the frame? It's the lower tube
> > not the top tube. Or do you think it's more likely
> > loading it on the bike rack would cause such a dent
> > rather than me riding the bike? Sure I'm 200 LBS but why
> > should I be able to cause a dent by my weight. How weak
> > are these bikes? I know you weren't there but I'm giving
> > you the scenario and maybe you can help with the
> > likelyhood of different causes.
> >
> >
> >
> >
> > Thanks,
> >
> >
> >
> > James
>
> My guess is that someone dented the down tube. My
> assumptions are you rode it around the parking lot with
> out running into anything with the front wheel.
>
> Reason 1: The downtube has a elongation forces when only
> riding the bike around while the top tube has compression
> forces. Denting would be the first signs of a crumpling
> effect caused by compression forces. I would expect to see
> that on the top tube not on the down tube from you being
> to heavy for the bike.
>
> Reason 2: At that level of a bike I doubt that the wall
> thinkness for the tube set is any different than that for
> let's say a 19 inch bike. A smaller frame should be
> stonger than a larger frame given the same thickness in
> the tube set. Even if the tube set it double or triple
> butted the smaller frame should be stronger.
>
> Of couse if what you mean by "I rode it for about a couple
> of minutes." means down a set of stairs with a four foot
> wall at the end then yes you may have dented it with your
> wieght...
>
> -p