Fork-mount fears

Had all of ours on the RR for years and no CF fork failures to date.
Drove all over TX & OK with them @ 55mph+. We even eliminated the
lawyer lips on one of them [mine:-)] and never had one come loose or
cause a problem.

I have however seen a bike on a RR vs Garage that did not fare well for
the fork but the rack did fine. Once you get used to them on there,
it's all good. Sort of like towing a trailer the first couple of
times....

I'm glad to hear you haven't had any carbon fork failures from the rack
(sorry, I cannot figure out how to auto-quote your post, so I'm
paraphrasing you).. It's just that I got the willies seeing my bike
held on by nothing more than the front dropouts (which are WAY below
the bike's center of gravity for being pushed by wind, cornering of the
car, etc..). Oh, I suppose the rear tire is technically supported as
well, but that doesn't comfort me for some reason.

But if folks keep telling me they've never hurt their bike this way
(short of the usual dumb disasters), then I'll quit worrying.

In article <[email hidden]>,

Quoted message said:

I'm glad to hear you haven't had any carbon fork failures from the rack
(sorry, I cannot figure out how to auto-quote your post, so I'm
paraphrasing you).. It's just that I got the willies seeing my bike
held on by nothing more than the front dropouts (which are WAY below
the bike's center of gravity for being pushed by wind, cornering of the
car, etc..). Oh, I suppose the rear tire is technically supported as
well, but that doesn't comfort me for some reason.

But if folks keep telling me they've never hurt their bike this way
(short of the usual dumb disasters), then I'll quit worrying.

Just to make you feel better, consider the stresses that the front fork
experiences when you are actually riding, and going around a tight curve
at 20+ miles per hour. The *rider* can be 8 to 10 times the weight of the
bicycle, so holding an *unloaded* bicycle by it's front fork should be no
sweat for the bicycle's structure.

--- Joe

In article <[email hidden]>,

Quoted message said:

I'm glad to hear you haven't had any carbon fork failures from the rack
(sorry, I cannot figure out how to auto-quote your post, so I'm
paraphrasing you).. It's just that I got the willies seeing my bike
held on by nothing more than the front dropouts (which are WAY below
the bike's center of gravity for being pushed by wind, cornering of the
car, etc..). Oh, I suppose the rear tire is technically supported as
well, but that doesn't comfort me for some reason.

But if folks keep telling me they've never hurt their bike this way
(short of the usual dumb disasters), then I'll quit worrying.

Just to make you feel better, consider the stresses that the front fork
experiences when you are actually riding, and going around a tight curve
at 20+ miles per hour. The *rider* can be 8 to 10 times the weight of the
bicycle, so holding an *unloaded* bicycle by it's front fork should be no
sweat for the bicycle's structure.

--- Joe

"Joe" wrote: (clip) consider the stresses that the front fork experiences
when you are actually riding, and going around a tight curve at 20+ miles
per hour. (clip)
^^^^^^^^^^^^^^^
Joe, the weight and cornering force combine to form a resultant force that
goes down through the front and rear wheels to the road. The bike and rider
lean to make this happen. This force is not trying to dislodge the skewer
from the cropouts.

On the other hand, Burnedtechie's fears are not justified by the experience
of the thousands of bikers who transport their bikes for thousands of miles
supported by the front fork. If this were a real problem, then we would all
be worrying about it.

burnedtechie said:

I've got a Yakima Viper roof rack which is a fork-mount type thing. My
bike is pretty light compared to my old hybrid (20 vs 30+ lbs) but I
still wonder how safe it is having a carbon-forked (or ANY-forked) bike
held onto the roof by its fork dropouts. Isn't there an *extreme*
amount of torque applied there on any cornering, crosswinds, etc? Yet
I never hear about damage unless the poster is talking about driving
into an obstruction or dropping the bike sideways before tightening the
skewer fully. Otherwise, no damage reports.

Why is this? Am I overestimating the stresses experienced or am I
underestimating the strength of the fork? Or both?

Yep. The weight of the bike is nothing compared to the weight of the
rider, and the fork holds up pretty well under the rider's weight,
including cross-winds, turns, and potholes that knock kinks into the
wheels.

I've been using this same rack for years. So have many others. Frankly,
I prefer fork mounts to those that clamp onto the downtube.

--

David L. Johnson

__o | Arguing with an engineer is like mud wrestling with a pig... You
_`\(,_ | soon find out the pig likes it!
(_)/ (_) |

In article <[email hidden]>,

Leo Lichtman said:

"Joe" wrote: (clip) consider the stresses that the front fork experiences
when you are actually riding, and going around a tight curve at 20+ miles
per hour. (clip)
^^^^^^^^^^^^^^^
Joe, the weight and cornering force combine to form a resultant force that
goes down through the front and rear wheels to the road. The bike and rider
lean to make this happen. This force is not trying to dislodge the skewer
from the cropouts.

On the other hand, Burnedtechie's fears are not justified by the experience
of the thousands of bikers who transport their bikes for thousands of miles
supported by the front fork. If this were a real problem, then we would all
be worrying about it.

Leo,

The OP was concerned with " underestimating the strength of the fork". My
post quite adequately covered that point.

--- Joe

"Joe" wrote: The OP was concerned with " underestimating the strength of
the fork". My post quite adequately covered that point.
^^^^^^^^^^^^^^^^^
Quite right, if you refer to his first post. In his second post, he says,
"It's just that I got the willies seeing my bike held on by nothing more
than the front dropouts," which leads me to think he is also concerned about
the skewer security. You were replying to something he actually he actually
said, and I shifted the emphasis to something ELSE he seemed to be saying.
I apologize.

Quoted message said:

I've been using this same rack for years. So have many others. Frankly,
I prefer fork mounts to those that clamp onto the downtube.

On the other hand, we've replaced a fair number of forks that were damaged
by roof racks that clamp to the fork's dropouts. Not damaged during actual
use, mind you, but rather while someone was trying to put the bike on it,
and before being able to secure the front Q/R, the bike managed to start
falling to the side, quickly (and severely) bending one of the dropouts.
Filing the dropout tabs can help in this regard, since it eliminates the
need to readjust the Q/R each time it's used (although later designs of
fork-mount roof racks have Q/R designs that no longer require readjustment
when used with lawyer-lip'd dropout... and yet people still manage to mangle
them).

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

"David L. Johnson" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

burnedtechie said:

I've got a Yakima Viper roof rack which is a fork-mount type thing. My
bike is pretty light compared to my old hybrid (20 vs 30+ lbs) but I
still wonder how safe it is having a carbon-forked (or ANY-forked) bike
held onto the roof by its fork dropouts. Isn't there an *extreme*
amount of torque applied there on any cornering, crosswinds, etc? Yet
I never hear about damage unless the poster is talking about driving
into an obstruction or dropping the bike sideways before tightening the
skewer fully. Otherwise, no damage reports.

Why is this? Am I overestimating the stresses experienced or am I
underestimating the strength of the fork? Or both?

Yep. The weight of the bike is nothing compared to the weight of the
rider, and the fork holds up pretty well under the rider's weight,
including cross-winds, turns, and potholes that knock kinks into the
wheels.

I've been using this same rack for years. So have many others. Frankly,
I prefer fork mounts to those that clamp onto the downtube.

--

David L. Johnson

__o | Arguing with an engineer is like mud wrestling with a pig... You
_`\(,_ | soon find out the pig likes it!
(_)/ (_) |

Once again, proof positive that you have to be smarter than the
equipment you [the general you] are operating.

Mike Jacoubowsky said:

On the other hand, we've replaced a fair number of forks that were damaged
by roof racks that clamp to the fork's dropouts. Not damaged during actual
use, mind you, but rather while someone was trying to put the bike on it,
and before being able to secure the front Q/R, the bike managed to start
falling to the side, quickly (and severely) bending one of the dropouts.

I lost a fork on a very windy drive through Bug Sur, just a few
weeks ago. The severe shaking of the bike eventually pulled out the
fork from the mount, breaking off a piece of one of the carbon
dropouts in the process. I had filed off the "lawyer lips", which
probably would have helped retain the fork in the wind.

I have now replaced my fork mount racks with wheel mount racks.
--
terry morse - Undiscovered Country Tours - http://udctours.com

mrbubl said:

Once again, proof positive that you have to be smarter than the
equipment you [the general you] are operating.

Accidents happen to even the smartest people. A front fork without a
wheel mounted is rather delicate.
--
terry morse - Undiscovered Country Tours - http://udctours.com