kawaray

I just stripped the components off of my 10-year-old, steel frame to have it repainted. Upon a quick inspection, I noticed that the top tube of this frame was ever so slightly bent. I have not had any "accidents" on this frame, and there were no signs of dents whatsoever. Instead, it appears that it was bent very gently by soft, but heavy objects exerting some force.

Only thing that I can suspect is the frame arm of the hitch rack that I use to transport my bikes: I use Swagman's Current. I was aware of some concerns that this type of mounting mechanism has on carbon bikes, but I had never thought it could exert enough force to bent a steel frame.

I am wondering if anyone has any tips on protecting frames when using this type of mounting mechanism on the hitch rack. I have been using Thule's frame adapter that wraps around the frame to protect the tube from scratching (and maybe distribute the force?). One thing I am thinking about trying is to make sure that the arm would come down on the lug at the seat tube in the future (I am thinking this would be the toughest part of the top tube).

I never had any concerns/complaints against the rack I use until now, so I am very much hoping that I can continue to use it after I get the issue sorted out on my frame (it is currently at a frame builder; if the worst comes the worst, I will have the top tube replaced, I think...). I will appreciate any tips/insights/suggestions.

Koyote

I very much doubt that your bike rack damaged the top tube… But if you are really worried, about $600 or $700 will get you a tray style rack.

kawaray

I have a tray style rack. It has the frame arm to mount it down onto the trays.

Koyote

I meant one like this, which does not contact the frame.

kawaray

No, I am not going to buy a different rack. As I mentioned in my original post, I am very much hoping to continue to use my current rack. So, I will appreciate any tips that people might practice when using a similar rack as mine; I just simply want to learn if I am missing out on anything.

jaxgtr

I used to have a Yakima Two Timer , but it was called something else, anyway, I used to have a piece of pipe insulation I would put over my top tube to protect the paint, I also wrapped the rack brace that would contact the frame with handle bar tape to also protect the frame, but it was more to protect the paint. Never had any issue with it bending the tubes, you might be cranking down on it too hard.

kawaray

The arm that presses down on the top tube has ratchets, so sometimes I had to press it down hard to engage the ratchet. So, I can see that there is a chance that I was cranking it down too hard. Maybe using the pipe insulation might be a good idea since it gives an extra layer to relieve the force on the top tube besides the tires (with 25C pumped up to 7 bar, I am not sure how much leeway those tires provided...)

Koyote

if you let some of the air out of those tires, to make them squishy,, then you don’t have to ratchet down as hard on that top bar… And there is a little more latitude for road noise to be absorbed by the tires rather than where the frame meets the ratcheting arm.

kawaray

I realize that I can let the air out of the tires, and that is what I do when I transport the bike on the rack over a long distance. When I just take it for a quick evening spin, however, I do prefer to pump the tire before I leave my place.

cyclezen

The 'current' already has straps for the wheel hoops, so not much chance of the bike coming dislodged. And so, no reason to bear down on the bar holding the bike down and in place. I would get some tube foam and add to the current foam to the hold-down hooks. Something with some thickness and give, but not too squishy.
Adding the extra foam will allow you to put a firm hold on the bike and still have some 'give' in the foam so it's not putting undo pressure. When you hit bumps and the bike moves a tiny amount, the foam will give and absorb the movement, without undue additional pressure/force on the bike.
That's what I plan on doing... I'm getting a swagman also ( the cheaper one), for those few times when I need to use a rack and keep cargo space in the SUV...
I really don;t need the super-delux other higher priced racks. Had my bike on another guy's swagman, and it's plenty fine for me (with the extra foam tubing...)
Ride On
Yuri

Ironfish653

^^^ Pretty much this.

The straps on the wheel trays are what holds the bike down; the top ‘hook’ is there to keep the bikes from tipping over or knocking into each other.

There’s no reason to have to reef down on the TT.
Or let the air out of the tires. I’m not why you’d lower the air pressure, before you strap it down by the wheels?

kawaray

So, when I didn't have the frame arm firmly pressing down on the top tube, there were considerable rocking by the bike on the rack. Mostly, fore and aft direction of the car, so toward the front and back. This seemed concerning to me for both the frame paint and the stability of the bike. So, I had been putting the extra effort to press down on the frame arm onto the top tube.

I think I like the foam tube idea. So, that might be what I will try to do when I get my bike back...

Doug64

I'm not sure how a person could bend the top tube by pushing the securing bar down by hand. I have a Thule rack, Double Track 990XT, and have hauled aluminum bikes on it without any damage. If a steel top tube can be bent by pushing on the retaining mechanism, then an aluminum top tube could be dented. I have a hard enough time just getting the bar snug, much less doing damage to the top tube. My Thule rack has 3/8" rubber sleeves around the retainer arms where they come in contact with the top tube. The rubber seems to offer some cushion while hold the bike snug.

Just out of curiosity, how much force do you estimate your are pushing on the retaining arms? What kind of bike do you have and what type of steel tubing is used for the top tube? Is the diameter of the top tube on the small side, or is it thin-walled double butted tubing?

I'm interested because my rack is very similar to yours, and it could be an issue I have never thought about.

cyclezen

so you're saying that your bike rocked in a front to back direction, towards back of car and then away (not front to back of the bike in rack - which would be side to side, relative to car...)?
Interesting, I didn't notice that, the few times I had my bike in friend's swagman.
but that generates another idea... there's another thread, here in BF, where a storage option was being discussed, to carry tube/usual repair stuff like levers, CO2, etc in a 'carrier'/pack down in the V of the BB area (as opposed to having in a saddle bag). Sortta Like the Specilized SWAT idea, only external.
Noted was that many mtb riders carry stuff, like a spare tube with a strap to secure to the downtube or seattube. I was thinking to do the same on my mtb - using Double-sided velcro - 2 inch wide.
I use double sided velcro for a lot of things, especially backpacking and when having to carry photo gear, securing a tail light to the seatpost, etc.
...so, I'll have extra 2" double velcro from the tube carry project.
For the bike carrier wrap the bike top tube where the hold down bar contacts, with a suitably sized piece 2" double sided velcro - fuzzy loop side toward the frame. This will protect the finish and the outer stiffer hook side will offer a little friction/grip to foam tube of the hold-down bar, to stop any sideways movement...
when removing from bike, I'll 'store' the velcro piece by wrapping it around the vertical support bar/stanchion...
should work fine...
Ride On Yuri

kawaray

Yeah, so when there was some space between the arm and top tube, it created a room for the bike to "tilt/rock" (in the direction that is side to side for the bike; toward front and back of the car). I was a bit paranoid about this, since I had a friend who had some incidents where this kind of movement of the bike created a torsion on the arm of a rack to nearly destroy his rack (it was a different rack, and I think the arm came down on the wheel on his rack; I don't even know what brand his rack was, and who knows if it was the only cause of the incident...). So, I have been extra cautious to minimize the amount of "movement" that my bike has on the rack.

kawaray

I have a steel frame road bike with horizontal top tube. I think it has double butted tubing, but I could be mistaken (if I remember correctly, it is a Tange tubing?).

I don't think the bent was caused by me exerting the force on the top tube. I am suspecting that it might be a combination of how the bike got "trapped" on the rack in a certain way (one thing I noticed was that trays on this rack slide, so there has been consistent tinkering on where they end up) and maybe the G-force from car driving at the highway speed? I am only suspecting on this, but this is the only thing that fits the description of "soft, but heavy object gently exerting the force" to bend the tube... And it was ever so slight bend that I did not notice at all while I was riding the bike; it became apparent only after I stripped the components off of the frame, and a bike mechanic (actually a frame builder) inspected it for alignment.

Ironfish653

Unless you take your car autocrossing every weekend, with the rack and bikes on the back, you're not putting the 'G's into the bikes you think you are.
Same for the 'soft but heavy' mystery force. If it was so soft that you weren't aware of it, it would have to have been to a very, very long time to put a bend in the tube. Possibly something very heavy was leaned against the bike, or the bike fell against something? It's possible that it could have been there the whole time.


I'm trying to prevent this from becoming one of those "correlation is causation" threads that seem to proliferate around here:. "Bike has bent top tube. Bike has been carried on rack; therefore, a Rack will Bend your Top Tube"

kawaray

Bike was bought brandnew. It did not have anything heavy lean on it for a very long time. Or, it did not fall on anything.

I am not certainly hoping to start a myth, nor do I think that every rack will bend a top tube. I am only exploring good habits to protect the frame while transporting a bike.

kahn

Just wondering if you might have hit a large bump/pothole and really jostled the bike up into the bracket and bent it. Those round tubes are really hard to bend.

kawaray

Yes, I thought those tubes are hard to bend; yet, it is bent on my bike. I feel like if a bump on the road is capable of bending it, then there are lots of different scenarios can be suspected, including the force exerted by the frame arm on my hitch rack I was not really suggesting a fraud in the design, but was thinking that a combination of my loading habit and/or some weird circumstances/behavior of the bike while on the rack could have made the bend. So, I was simply hoping to get some insights from folks who had a similar rack about how they typically load their bikes to avoid any damages to the frame.

I understand that this inquiry is not to liking of some members, so I will retract it.

jsilvia

I have the Kuat, best rack I ever owned.

kawaray

Are there anything that you particularly pay attention to when you mount your bike on the rack with a frame arm? For example, where do you position the frame arm to come down along the length of the top tube? The instruction for my rack specified that the arm should come down at the lowest point on the top tube, but I have a traditional steel bike with horizontal frame, so "the lowest point" is rather moot. I am now wondering if I should have the frame arm come down on the lug at the seat tube?

cyclezen

You're being a little 'tender', this is the internet... LOL!
take what you think is applicable... the reason this works is because you WILL get a broad spectrum of responses...
How to get a bend...
Well, if you are anything like me - I am that guy who always tightens 1/4 turn too much and strips the thread... LOL!
if you bear down on the arm and put ever so light a bend into the TT, time in the rack, over multiple iterations, could progressively put a very slight bend into thin steel tubing.
I have a ton of experience in 'coldsetting' rear triangles of older steel frames - to fit newer hub sizes... 120 to 126, 126 to 130.
It doesn' take a lot of effort to do this cold setting... and once set, it doesn't spring back...
don;t be that 'cold-set' guy - snug is fine, especially if you have decent tire pressure...
Your thread has warned to to NOT be that 'Cold-set' guy.... LOL!
Ride On
Yuri

Elvo

I would recommend securing the bike by locking the rack arms onto the wheels, not the frame itself

sarhog

I would recommend being familiar with the rack in question prior to recommending methods to use said rack.