Pat wrote:
> I have to stronger disagree with this one. I was rear-ended (without bikes
> on the carrier) and the ONLY damage was that the insurance company had to
> buy me a new Sport Works rack. They were pretty happy about that and told me
> that without the hitch, the entire back end of the car would have had to be
> repaired. I can only think this comment about "thousands of dollars worth of
> damage" is pure speculation, based on my experience.
Unfortunately it isn't speculation. It happened to me on a Honda CR-V. I
was hit from behind. The bumper took none of the impact because the
other vehicle hit the rack. The rack transferred the force to the floor
pan, which was damaged beyond repair and had to be replaced at more than
$2000. Ironically the rack was not damaged.
> You don't stick out too far without bikes on the rack.
This is true, provided the rack arms fold down.
> Oh, now I get it. All of your writing has been speculative. You don't know
> anything about this. I do have a Honda Accord with a rear hitch-mounted bike
> rack. I can tell you it hasn't been a problem. Sometimes, I lower the rack
> to enable me to put something in the truck, but then I raise it back up
> again.
Oh please, you don't "get" anything, you're simply clueless. I have both
types of rack. Currently I use a Performance Xport 4 bicycle hitch rack
used on an SUV with a frame mounted hitch
("http://www.performancebike.com/shop/Profile.cfm?SKU=22746"). I also
have Thule crossbars for a Camry, and four bike mounts, as well as a
tandem mount (which can't be on a hitch rack without sticking too far
out to the side). Each type of rack has its pros and cons. The roof rack
adds wind noise and wind resistance, and you have to be aware of low
branches, low parking garages, and even some low overpasses. The hitch
rack sticks far out behind the vehicle, subjects both the vehicle and
the bicycles to more risk from damage in a collision, and should be
removed when not in use.
It's always amusing to see someone desperately defend something they
purchased by failing to acknowledge the trade-offs present in any
product, and then getting angry when someone else points them out.
For those actually interested in learning something, I have taken some
excerpts from my web page on rack selection.
Issues with Hitch Racks
-----------------------
Rear End Collisions
-------------------
When the hitch rack is installed on your vehicle the bumper is not
functional. If someone bumps into the back of your vehicle, with the
rack installed, it can cause thousands of dollars worth of damage even
if it is only a very low speed collision. I speak from personal
experience here. Someone ran into the back of my car hitting the hitch
rack. The hitch rack pushed a hole up through the floor of the car
causing nearly $3000 of damage. Had the rack not been installed I
probably would have only needed a new bumper cover at a cost of about
$300. Remove your hitch rack when not in use!
Non-folding arms stick out too far
----------------------------------
This is an issue only with racks whose arms don't fold down. On racks
with folding arms you should take the time to fold them when parking
with the rack still on the car.
Bicycle Damage
--------------
If someone rear-ends your car then all of the bikes will probably be a
total loss.
Width (only an issue with horizontal tandem racks)
--------------------------------------------------
The tandem can be wider than the vehicle on the horizontal tandem racks.
You probably will want to remove the front wheel to save a foot or so.
Just be careful not to hit anything with the bike (including other cars
on either side of you on a multi-lane road).
Exhaust Pipes
-------------
Be certain that hot exhaust is not blowing directly on the bicycle. This
is a common problem if the bikes are installed onto the rack
incorrectly. If the bike is such that one wheel is lower on the rack
then put the bike on so the lower wheel is on the side of the car
without the exhaust pipe.
Ground Clearance
----------------
Be sure that the bicycles are high enough off the ground (the wheels
shouldn't be lower than the bumper). If the rear wheels went into a
shallow dip or over a high speed bump, the wheels could hit the ground
and be damaged. This is usually not a problem, but some hitch racks have
height adjustable masts and if the mast is adjusted too low then the
bike wheels could be too low.
---------------------------------------------------------------------------
What to Look for in a Hitch Rack
--------------------------------
Spread. If the rack holds the top tube with two arms, how far apart are
the arms? You want them far apart enough to provide good support, but
close together enough so that short frame bicycles can be carried. Avoid
hitch racks where the frame is held by a narrow clamp of six inches or
less; they have compromised the design to avoid the cost of two separate
arms.
Do the arms fold? When you park, or if you keep the rack attached all
the time (a bad idea), you'll want to be able to not have the arm(s)
sticking several feet out toward the back of your vehicle. An injury
could invite a nasty lawsuit. Thule's, Rhodegear's Interstate series,
and Yakima's RimRoc all have folding arms.
Rear access. Does the rack fold down or pivot out far enough for you to
open the back of your van or SUV. The more expensive racks that pivot
let you gain access to the rear even with bicycles on the rack while the
fold down racks require that you remove the bicycles first. The cheapest
ones neither pivot or fold down.
Spare tire clearance. If you have a vehicle with a spare tire mounted on
the back be sure that the rack clears it.
Wobble. If you use a standard hitch pin to secure the rack then it will
wobble and rattle. There are several systems designed to eliminate
wobble, from a collar with set screws to the use of a threaded bolt that
secures the rack to the hitch rather than a pin.
Hold Downs. Some of the cheaper racks just have some hooks, you have to
use bungee cords or other tie-downs to hold the bike. The better ones
have cushioned rubber pads with straps. Unfortunately the only ones that
have integral locking are the poorly designed single arm racks; with the
others you have to use a cable lock.
Security. How is the rack locked to the hitch? How are the bikes locked
to the rack? The advantage of the single arm racks with a solid mounting
hold down plate over the top tube is that it it make the rack lockable,
but the disadvantage of the single arm rack is so great that I would not
use one just for this reason; you can just use a heavy cable lock.
Swinging. On the racks that hold the bike by the top tube, the bike can
swing back and forth while on the car. Some of the more expensive top
tube mount racks have a bottom support bar sticking out down near the
wheels for you to secure the bottom of the bike.
Removeability. How fast and easy is it to remove the whole rack? Some
of the RhodeGear racks are easy to partially remove but they leave the
base sticking out beyond the bumper which is a very bad idea.
Storeability. How easy is it to store. The racks with arms that don't
fold down, and/or masts that don't fold, are a pain to store because you
can't store them flat. The pivoting masts are also a pain to store, but
you gain the advantage of easier access to the rear of the vehicle.
Odd frames and Children's Frames. A lot of the hitch racks that hold the
bikes by the top tube have a problem with odd frames, mixte ("ladies")
frames, and children's frames. The racks that hold the bike by the
wheels and crankarm will be easier to use with these. There are
attachments to create a fake top-tube to use the top tube racks with
mixte frames. On the top tube racks with dual arms you may be able to
put children's bikes on them by hanging the bike by the wheels.
Other accessories. Many hitch racks have attachments available for skis.
Weeding out the Junk and Making an Intelligent Choice
-----------------------------------------------------
The reality is that most of the hitch racks are not well designed and
it's easy to weed out the bad ones. IMVAIO, on the hitch racks with top
tube mounts you should look for:
* Dual fold-down arms
* Pivot-out or fold-down mast
* Anti-wobble device included
* Integral locking of the rack to the hitch
* Rubber Hold-downs with straps that don't come off to lose
* Bottom support bar to prevent bikes from swinging
* Comes with bicycle locking mechanism (standard)
Also look at the hitch racks where the bicycles don't hang from arms,
but sit in wheel trays.
----------------------------------------------------------------------------
Issues with Roof Racks
Height
------
With a roof rack you need to be very careful about where you drive. Of
course you can't drive into your garage with your bike on the roof
(though many people have done this). You also need to watch out for
parking garages, trees with low branches, car washes, fast food
drive-throughs with awnings, etc. Someone e-mailed me saying that
'everyone' with a roof rack has driven under an overhang or into a
garage with the bikes on the roof. Knock on wood, but in twenty years of
using roof racks I've never done this.
Spread
------
The crossbars need to be a minimum distance a part to carry some longer
items like tandem bicycles. There are ways to get around the minimum (a
little anyway) that I've seen (but there are no guarantees of the wisdom
of doing this). It isn't just the length restriction for the
attachments, it's how secure the rack is held onto the roof when the
crossbars are close together. If the restriction is due only to the
distance between the crossbars then you can often reinforce the
attachment. For example, on bike mounts where the short roofline causes
the wheel tray to extend too far, you could reinforce the wheel tray
with aluminum angle which eliminates the flex (the tray is made of thin
stamped steel) and adds support. Check
http://www.onlinemetals.com for
aluminum angle. Doing this sort of thing is entirely at your own risk.
Wind Resistance
---------------
Roof racks, even when they are empty, create a lot of wind resistance.
There will be a measurable, non-trivial, reduction in fuel economy with
a roof rack.
Wind Noise
----------
Since a roof rack and its accessories are not smooth, the wind going
across them will create noise. Sometimes pieces of the rack will go into
oscillation causing hum. A fairing can be used to direct air over the
rack but the fairings are often incompatible with the other accessories.
Lateral Forces
--------------
High cross winds can exert tremendous forces on roof rack accessories.
Ensure that your rack is securely mounted to the vehicle. Sometimes
crossbars are attached to the vehicle's roof rack mounts, which are only
screwed into the roof with sheet metal screws. Bicycles in fork mounts
are putting a lot of stress on the fork dropouts. Be sure that the
clamps that secure the dropouts are very tight and that they can't pop open.
Headset Bearing Fretting
------------------------
When the vehicle is in motion shock from the road is transmitted up to
the roof rack. When a bicycle is clamped by the fork, into a fork mount,
the fork and headset are held rigidly in place. As the vehicle goes down
the road the headset will be constantly absorbing small shocks. This
would not be a problem if the headset were also turning, because the
lubricant inside would be distributed by the rolling of the bearings.
But the headset is not turning and therein lies the problem. From:
http://draco.acs.uci.edu/rbfaq/FAQ/128.html: "The damage occurs when
these small motions occur when there are no steering motions to
replenish lubricant while the bearing balls fret in place. Fretting
breaks down the lubricant film on which the balls normally roll and
without which they weld to the races and tear out tiny particles." This
was written by Jobst Brandt, a well known and well respected engineer
and author of _The Bicycle Wheel_.
On upright mounts the wheels are absorbing the shock from the road but
on fork mounts the shock is being absorbed by the headset though it is
unknown how much extra wear occurs because of fretting. For obvious
reasons some people claim that the extra wear is trivial, though they
have no way of quantifying it.
Bugs
----
Enough said.
Wind and Lubrication
--------------------
Jay Hardcastle wrote: "The biggest risk to bike on a roof rack (aside
from overhangs) is the wind forcing moisture in and lubricants out.
(Handlebar tape and saddles also take a beating.) A Lycra or Neoprene
transport cover (bike bra, or Xport) can help with either; plus no bugs
to clean-off!" This is good advice.
