By Jim Langley
“I have a Giant Defy Advanced bike with a carbon frame. When transporting my bike by car, I was told not to use a bike rack that held the bike from the top tube, but to get a rack where the bike sat on wheel supports. True?”
“Andy, I think the best thing to do would be to try calling Giant USA and asking one of their tech people just to be 100% sure you know the issues. It might be that the weight of the bike hanging from the top tube could place enough stress on the carbon to create an issue at the holes for the internal cables.
“When you ride a bicycle, the top tube is compressed and at little risk. But when you hang a bike from the top tube, the weight pulls down on the top tube. I find it hard to believe the weight of a featherweight bike could damage the tube, but if you hit a big bump? Maybe something like that is what they are worried about. To be safe, I would probably just go get a piece of PVC tubing, cut it to length to make a brace for the bottom of the top tube, line it with some foam padding, and you would be good to go.
“The entire top tube would be supported and padded, and that should ensure nothing can damage the tube. You’ll probably have to shape the PVC a bit to clear the cables but that shouldn’t be too hard. You can keep this custom support in your car so it’s always with the rack.
“I think something like that will put your mind at ease and prevent any possible issues with the bike or Giant. Hope this helps! If you find out something from Giant, please let us know.”
No word from Giant yet, by the way.
The risks are real
Not to scare you, but I’ve seen more bicycle damage caused by car-rack use and abuse than I care to remember. And, I’m just talking about with my own bikes, including the heartbreaking incident when I drove into my garage with my oversize 1885 museum-quality restored highwheel on the back of my car and — you guessed it — smashed it into the door.
But, it’s not just me. Team drivers have been known to lose bicycles off of roof racks; a month ago I saw a bike lying in the highway, about to be run over as the poor owner who had parked his car with trunk-rack on the shoulder was about to play Frogger to try and retrieve it; and a frame-builder friend just told me a customer took his carbon bike off the roof rack after a trip and found that a rock had shot right through it, severing one of the seatstays!
And, even worse than the bicycle damage is what can happen to your vehicle should the rack or bicycle(s) smash into it or get torn off it. To help you avoid such calamities, here are some safety tips organized by rack type. I know I won’t cover everything, so please share your own bike rack horror stories and tips for preventing them on our Community Comments page. Help save a bike and/or car!
The biggest risk is driving into something too low, and experience suggests that it’s nearly impossible to remember your precious cargo is up there. Out of sight, out of mind — unfortunately. You might try a sign on your dashboard reading “BIKES ON TOP!”
A tip I’ve heard for when you get home is placing your garage-door remote control in your bike glove so it reminds you. I’ve seen flags that drop down when your garage door opens and even little pop-up signs you stick to your car’s hood that appear when you slow to parking speeds (the wind pushes them down). But I don’t know if anyone is making these anymore (you could make your own).
An easy mistake to make on a roof rack that holds bikes by the front fork (front wheel removed) is pulling a bike off and damaging or even breaking your fork. This can happen because the bike is overhead and hard to handle. If you don’t fully open the roof rack’s quick release, and lift the fork up and out, you might pull sideways while the fork dropouts are still engaged. This can bend or break an aluminum dropout.
Tip: Remember that rock I mentioned that shot through the carbon bike? That guy needed a bike bra. These covers go over the front of the bike and protect it from the wind as it rides up top. The Trek Bike Bra sells for $39.95. Besides preventing things from striking your bike, it’ll keep the grease from being blown out of your bearings on a stormy, long drive, and protect your finish, too.
While carrying your bikes on the back of a vehicle means they’re protected from the wind and airborne debris, you still can’t forget about them. Because it’s almost as easy to back into something and smash your bikes as it is to whack them off a roof rack.
The beauty of a rear rack is that, in most cases, you can see the bikes when you check your mirror(s), so you get that constant reminder. But there are other hazards.
Strap-mount trunk racks need to be installed carefully and correctly. And, it’s not always easy or logical how the straps, buckles and tensioning devices work. So, read the directions and make sure you understand how to securely install the rack, or ask for help from the rack manufacturer or the bike shop where you purchased the rack.
Tip: Over time and with use, straps can stretch, and they may run through holders that can change position, creating slack. For trunk racks to stay put, the straps need to stay tight. So check them regularly and keep them tight, which will help keep and your rack and bikes safe.
Bumps can cause the rack and bikes to bounce around. If you’re carrying several bikes on a trunk-mount rack, they may bump into each other, which can also damage them. Be sure to check for this when you’re putting your bikes on the rack, and place padding between them that won’t move when you’re driving.
Most importantly, beware the exhaust pipe(s) on your vehicle. If your bikes or wheels are near the exhaust, it can and will melt rubber and plastic — and ruin your tires/tubes, wheel reflectors and other accessories.
Hitch racks, which are also called receiver racks, are supported by the super-strong welded-on square-steel channel (the “hitch,” or “receiver”) beneath your vehicle. Because the hitch is so strong, these car racks can carry many bikes in many different ways, depending on the design of the rack.
Because the hitch racks protrude from the back of the vehicle rather than resting against it like most trunk racks, it means you have to remember that your vehicle is longer now when you’re backing up and turning (in effect, the more bikes on the rack, the longer your vehicle).
Hitch racks are so sturdy it can seem safe to just place the bikes on them and let gravity hold them in place. That’s not a good idea. The hitch is attached to the back of the car and it acts as a lever, amplifying bumps and transferring the force to the rack and bikes. An unsecured bike could fly right off the rack. Be safe by attaching the bikes to the rack in such a way they can’t come off or bang into each other.
And even the strongest-looking rack should have a per-bike weight limit and a total bike capacity that you don’t want to exceed, even though it may seem like the rack can handle more. Don’t overload these racks, or they could fail and your bikes might fall off, or worse.
With any rack, check it and the bikes at stops on your trip to make sure everything’s tight. I would recommend not letting your riding buddies put their bikes on your rack unless you’ve taught them how to use it properly. Like your other bicycle gear, inspect your car rack, maintain it and make sure it’s safe and sound, not rusting away, with frayed straps and ready-to-fail connectors. And, if you’re not using a rack, remove it from your car and store it out of the weather so it doesn’t corrode and break down. Keep it safe for use when you need it (most racks fold to make this easier).
Jim Langley has been a pro mechanic and cycling writer for 38 years. At RBR he’s the author of Your Home Bicycle Workshop and moderator of the technical forums on the Premium Site . Check his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter.