# Do you carry a carbon-framed bike on a car rack?



## LVbob (Mar 24, 2014)

Just out of curiosity, do people carry carbon bike on runk-mounted bike racks? The manufacturers discourage this but I am wondering what people do in the real world.


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## mjduct (Jun 1, 2013)

I do, if I get in a wreck, I'm going to lose it no matter where it is...

you put your 100 lb+ ass on it, it kicks up rocks and gravel into the frame at 20+ mph what is the 13-19 lbs of the bikes weight stretched out over 3-4 locations going to hurt?


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## bradkay (Nov 5, 2013)

One concern would be rough roads. Having a carbon (or this aluminum) frame bouncing up and down on the rack could be detrimental to the life of the frame. I suspect that this concern could be eliminated by using a rack that secures the frame tightly against the rack as opposed to one that it just slides on to.


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## LVbob (Mar 24, 2014)

bradkay said:


> One concern would be rough roads. Having a carbon (or this aluminum) frame bouncing up and down on the rack could be detrimental to the life of the frame. I suspect that this concern could be eliminated by using a rack that secures the frame tightly against the rack as opposed to one that it just slides on to.


I think that is the point that the manufacturers are making: the top tube should not be clamped. It seems that I've seen some carbon bikes on trunk-mounted racks and I'd like the convenience of not having to remove the front wheel and getting it into the back seat but I don't want to risk damaging the frame (although this frame has already been crashed so it might need to be replaced).


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## bradkay (Nov 5, 2013)

LVbob said:


> I think that is the point that the manufacturers are making: the top tube should not be clamped. It seems that I've seen some carbon bikes on trunk-mounted racks and I'd like the convenience of not having to remove the front wheel and getting it into the back seat but I don't want to risk damaging the frame (although this frame has already been crashed so it might need to be replaced).


If it is tightly secured with a rubber strap then there should not be any problem. If it uses a mechanical clamp I would avoid it. That being said, if it uses the rubber straps on the top tube but the down tube or any other frame part rests against the rack you could still encounter impact damage. 

Roof racks or hitch racks that use a mechanical clamp on the frame tubes should be avoided as well - any mechanical clamp tightening on the thin walled tubes of the bike can destroy the bike. In bike shops for decades we would clamp the bikes in our stands on the seat tube just below the junction with the top tube (partly because of the tendency in those days of idiots to sell and purchase bikes way too big for the customer leaving no seatpost exposed to clamp upon). No more - the mechanical clamp can crush that tube.


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## JoelS (Aug 25, 2008)

Absolutely not. There's no way I'm resting my CF bike on the top tube on one of those racks. Top tubes are not built for those stresses, they're built for the stresses of riding. I use a hitch mounted rack that holds the bike from under the wheels.


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## LVbob (Mar 24, 2014)

JoelS said:


> Absolutely not. There's no way I'm resting my CF bike on the top tube on one of those racks. Top tubes are not built for those stresses, they're built for the stresses of riding. I use a hitch mounted rack that holds the bike from under the wheels.


I know a hitch mount is the right way to go but I drive a sports car. I have to borrow one of my parents' cars to get the bike in the car. I guess I'll just continue doing that.


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## tlg (May 11, 2011)

LVbob said:


> I think that is the point that the manufacturers are making: the top tube should not be clamped.


^^ This. If you're going to go with a trunk mount get one with straps to secure, not clamps. 
There's no problem with putting a carbon bike on a bike rack. The forces are no where near what a bike sees in regular use with a 200+ plus man riding 40mph down a hill over bumps and holes. 


I don't like to use racks that secure the bike by the frame, not because of cracking it, but because over time they start to mark up and wear off the paint. No matter the frame material. I only use hitch mount racks which carry the frame by the wheels. Easier/faster to load and unload too.


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## tlg (May 11, 2011)

LVbob said:


> I know a hitch mount is the right way to go but I drive a sports car.


What's the sports car? Hitches are available for just about every car out there.


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## Devastazione (Dec 8, 2011)

Probably I would rather carry my wife on the rack rather than my bikes....:biggrin5:


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## LVbob (Mar 24, 2014)

tlg said:


> What's the sports car? Hitches are available for just about every car out there.


Mercedes SLK Roadster


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## tlg (May 11, 2011)

LVbob said:


> Mercedes SLK Roadster


Mercedes-Benz SLK-Class Trailer Hitch | etrailer.com


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## pone (Sep 19, 2012)

LVbob said:


> Mercedes SLK Roadster


Road // Titanium | Firefly Bicycles

Seven Cycles | Axiom SLX


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## LVbob (Mar 24, 2014)

tlg said:


> Mercedes-Benz SLK-Class Trailer Hitch | etrailer.com


I'm going to look into this. It's not like I need to transport my bike that often (yet) but it'd be nice to know that I have an easier way. Although my dad loves driving my car when I borrow his.

I do see an SUV coming sometime in the future…can have the security of the bike inside the car with little hassle.


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## mjduct (Jun 1, 2013)

I put mine in a saris bones 3 bike rack, and I promise it gets a small fraction of the pressure on the top tube as climbing out of the saddle does or sitting on the tube at a light.

I also use an old tube to fasten the front wheel to the rack, so 4 points of contact with rubber straps on a 12.5 lb bike I'm not worried bout it


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## looigi (Nov 24, 2010)

Yeah. Pretty common to sit on the top tube waiting for a race to start, etc.. And you can certainly pick up the bike by the top tube with one hand without fear. Holding it with straps at two points is not likely to exceed these stresses. The worst that will happen is the finish getting scuffed by the straps or grime under them.


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## redroab (Feb 13, 2014)

LVbob said:


> I'm going to look into this. It's not like I need to transport my bike that often (yet) but it'd be nice to know that I have an easier way. Although my dad loves driving my car when I borrow his.
> 
> I do see an SUV coming sometime in the future…can have the security of the bike inside the car with little hassle.


I considered getting a hitch for my coupe, but decided against it. Sure, it would be convenient, but it looks _hideous._​


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## tlg (May 11, 2011)

So here's a stress analysis I just ran. First one is equivalent of a 200lb rider sitting on the bike. Second one is the weight of a 20lb bike on one bike rack support. Notice the stresses are 30 times less when resting on a bike rack.


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## dcorn (Sep 1, 2011)

LVbob said:


> Mercedes SLK Roadster


Well there's your problem...




tlg said:


> So here's a stress analysis I just ran. First one is equivalent of a 200lb rider sitting on the bike. Second one is the weight of a 20lb bike on one bike rack support. Notice the stresses are 30 times less when resting on a bike rack.


How exactly did you model the carbon layup there? Is it paper thin on the top tube? Those diagrams don't really show anything relevant to this argument other than where the forces are on the bike.


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## tlg (May 11, 2011)

dcorn said:


> Those diagrams don't really show anything relevant to this argument other than where the forces are on the bike.


 It shows the stress locations and magnitude of stress. The "stresses are 30 times less when resting on a bike rack". 

Worry about riding your bike, not hanging it on a bike rack.


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## LVbob (Mar 24, 2014)

redroab said:


> I considered getting a hitch for my coupe, but decided against it. Sure, it would be convenient, but it looks _hideous._​


There is that. Convenience, aesthetics….more to think about. Borrowing my dad's car is really not such a big deal; I pick it up one evening and return the next afternoon. not like I'm rushed or anything.


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## Srode (Aug 19, 2012)

JoelS said:


> Absolutely not. There's no way I'm resting my CF bike on the top tube on one of those racks. Top tubes are not built for those stresses, they're built for the stresses of riding. I use a hitch mounted rack that holds the bike from under the wheels.


Exactly


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## Blackbeerthepirate (Apr 26, 2011)

So, are CF bikes so delicate that a hanging rack isn't supposed to be used?

I haul one around quite often and know many people who do the same with no problems. I have a Yakima Double Down that I really like. Had some kind of Thule before that,that was pretty nice. 

If you are getting a hanging rack, a couple of things I learned the hard way;
Always get one that fits more bikes than you think you'll carry. That way you don't have to space them as tightly or you can give somebody a ride home.
Get something that doesn't let the bikes wave around. Yakima has a seat tube cradle that holds them pretty steady.


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## tihsepa (Nov 27, 2008)

I ride mine. Not into parading around town with my bike on the car.


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## bradkay (Nov 5, 2013)

tihsepa said:


> I ride mine. Not into parading around town with my bike on the car.


Then you never take it on vacation with you or for weekend road trips. That's cool, but I like exploring new areas. 

I prefer a fork mount roof rack on my station wagon. The back end of the car is filled with camping gear and having a bike behind the car leaves it vulnerable to destruction by tailgating idiots. Since my bikes are worth more to me than my car, I prefer keeping them out of danger.


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## Duane Behrens (Nov 8, 2013)

JoelS said:


> Absolutely not. There's no way I'm resting my CF bike on the top tube on one of those racks. Top tubes are not built for those stresses, they're built for the stresses of riding. I use a hitch mounted rack that holds the bike from under the wheels.


Interesting. I've made 4 or 5 trips from southern California to northern Minnesota with both carbon bikes strapped down to a stock Hollywood rack. And back. 

The bikes are fine.


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## Rokh Hard (Nov 25, 2013)

ive been strapping my Pinarello Rokh and Bianchi Intenso to a Yamika Swingdaddy for months, no issues whatsoevah......however i recently purchased a new Yakima HoldUp ....got tired of removing the tire and strapping them in all the time with the swingdaddy. love that holdup. great rack and got a smokin deal on it at REI anniversary sale last weekend.


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## Rokh Hard (Nov 25, 2013)

tlg said:


> Worry about riding your bike, not hanging it on a bike rack.


bingo.


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## Jwiffle (Mar 18, 2005)

bradkay said:


> If it is tightly secured with a rubber strap then there should not be any problem. If it uses a mechanical clamp I would avoid it. That being said, if it uses the rubber straps on the top tube but the down tube or any other frame part rests against the rack you could still encounter impact damage.
> 
> Roof racks or hitch racks that use a mechanical clamp on the frame tubes should be avoided as well - any mechanical clamp tightening on the thin walled tubes of the bike can destroy the bike. In bike shops for decades we would clamp the bikes in our stands on the seat tube just below the junction with the top tube (partly because of the tendency in those days of idiots to sell and purchase bikes way too big for the customer leaving no seatpost exposed to clamp upon). No more - the mechanical clamp can crush that tube.


You didn't just simply raise the seat post to put it in the stand?

As for the OPs question: I know many riders who carry their carbon bikes on trunk racks without issue. Those who think it hurts the frames are worried without cause. Now, marring the paint finish, yes, I've seen that happen plenty, but it doesn't jeopardize the actual integrity of the frame. Thule makes the Raceway platform trunk rack, which is really nice. The wheels sit in trays, and the top tube is simply held in place with a rubberized clamp (you don't actually tighten it at all, just enough to keep the bike from falling sideways. Easier to use than most trunk racks, and one of only two lockable trunk racks I am aware of (the other is a Thule hanging style rack).


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## Rokh Hard (Nov 25, 2013)

i LOVE my new Yakima HoldUp - 

Review of the Yakima HoldUp 2 Hitch Bike Rack - etrailer.com - YouTube


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## inthesticks (Oct 27, 2010)

We have hauled ours on a Saris Bones 3 for a couple years 3-4 times a week without any issues. I think we have to understand that these bikes only weight 15lbs..and its it attached at 2 points on the top tube.
Since I have started hauling them in my truck via fork mounts and a hitch (Saris Thelma) for the car.


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## ziscwg (Apr 19, 2010)

tihsepa said:


> I ride mine. Not into parading around town with my bike on the car.


I have to ride around with mine to find other riders at coffee shops. then, I park 3-4 blocks a way and ride up acting tired. I mumble something about 75 miles and 10,000 feet somewhere in there to impress the crowd.


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## Rokh Hard (Nov 25, 2013)

ziscwg said:


> I have to ride around with mine to find other riders at coffee shops. then, I park 3-4 blocks a way and ride up acting tired. I mumble something about 75 miles and 10,000 feet somewhere in there to impress the crowd.



yer a champ


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## NJBiker72 (Jul 9, 2011)

mjduct said:


> I do, if I get in a wreck, I'm going to lose it no matter where it is...
> 
> you put your 100 lb+ ass on it, it kicks up rocks and gravel into the frame at 20+ mph what is the 13-19 lbs of the bikes weight stretched out over 3-4 locations going to hurt?


This. Seriously they are made of carbon not paper machet.


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## tednugent (Apr 26, 2010)

Rokh Hard said:


> i LOVE my new Yakima HoldUp -
> 
> Review of the Yakima HoldUp 2 Hitch Bike Rack - etrailer.com - YouTube


As long as the tire is knobby (ie my MTB and CX bikes), the holdup is fine

The "strong arm" slips on smooth road bike tires


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## NJBiker72 (Jul 9, 2011)

bradkay said:


> Then you never take it on vacation with you or for weekend road trips. That's cool, but I like exploring new areas.
> 
> I prefer a fork mount roof rack on my station wagon. The back end of the car is filled with camping gear and having a bike behind the car leaves it vulnerable to destruction by tailgating idiots. Since my bikes are worth more to me than my car, I prefer keeping them out of danger.


Very much in danger of garages and car ports though.


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## wanton007 (Mar 9, 2011)

I just ordered the Sea Sucker Mini bomber.

SeaSucker | Vacuum Mounting Systems

I need a bike rack that was easily movable between 2 vehicles (potentially more) and also work with my wife's step through bike (basically no top tube). And the advantage of not having to purchase 2 hitches for 2 cars and the ease of installing / removing the sea sucker made one a no brainer for me. 

I did do a bunch of research on multiple forums for reviews and the majority are favorable.


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## duriel (Oct 10, 2013)

Are you serious, HTFU. Put the bike on any bike rack!


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## Srode (Aug 19, 2012)

looigi said:


> Yeah. Pretty common to sit on the top tube waiting for a race to start, etc.. And you can certainly pick up the bike by the top tube with one hand without fear. Holding it with straps at two points is not likely to exceed these stresses. The worst that will happen is the finish getting scuffed by the straps or grime under them.


The concern is not the static load when picking it up or holding it, the problem is the shock load when you hit pothole or speed bump etc. The CF top tube is not made to take a point load as you can tell from looking at most. They are wider across, thinner top to bottom. If in doubt, ask your manufacturer and see what they say. I know when I bought mine I was told not to transport it hanging from the top tube as damage could occur and it would not be covered by warranty.


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## bradkay (Nov 5, 2013)

NJBiker72 said:


> Very much in danger of garages and car ports though.


I've been using roof racks since the early 1980s and have never come close to driving into a car port, garage, drive through, etc with my bike on the roof. The worst I have done is to collect a few leaves from a low hanging branch...

If you are a serious cyclist and love your bike how can you forget that you have it on the rack? 

The way I look at it is that I am in control of what happens to my bike on the roof but when it is on the back of the car the bike is vulnerable to whatever idiot is tailgating me (and there are a lot of those out there!).


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## NJBiker72 (Jul 9, 2011)

bradkay said:


> I've been using roof racks since the early 1980s and have never come close to driving into a car port, garage, drive through, etc with my bike on the roof. The worst I have done is to collect a few leaves from a low hanging branch...
> 
> If you are a serious cyclist and love your bike how can you forget that you have it on the rack?
> 
> The way I look at it is that I am in control of what happens to my bike on the roof but when it is on the back of the car the bike is vulnerable to whatever idiot is tailgating me (and there are a lot of those out there!).


True but put the bike further in on the rack. And it is their responsibility if they hit you. 

I know guys that love their bikes that have done the garage demo. I could see myself doing it if I drive home from a hard century.


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## bradkay (Nov 5, 2013)

NJBiker72 said:


> True but put the bike further in on the rack. And it is their responsibility if they hit you.
> 
> I know guys that love their bikes that have done the garage demo. I could see myself doing it if I drive home from a hard century.


Putting the bike further in on the rack will not save it when you are rear-ended. My bikes are nearly all irreplaceable so even if the idiot who rear-ended you is insured (not a given anymore) I will get shafted. 

I fully believe that only idiots will drive their nice bike into the garage. I repeat, in thirty-plus years of using roof racks I have never even come close to such a stupid move.


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## NJBiker72 (Jul 9, 2011)

bradkay said:


> Putting the bike further in on the rack will not save it when you are rear-ended. My bikes are nearly all irreplaceable so even if the idiot who rear-ended you is insured (not a given anymore) I will get shafted.
> 
> I fully believe that only idiots will drive their nice bike into the garage. I repeat, in thirty-plus years of using roof racks I have never even come close to such a stupid move.


It will help from a slight tap. 
No bike is irreplaceable. It is a thing.


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