You're talking about the weight of 4 bicycles.....so, based on that I see no issues with utilizing the adaptor.

There are devices made to secure the hitch to the receiver (i.e. remove the "wiggle"). They're cheap.

i think you're fine. until you want to TOW something with it. then you're not fine. all these hitches have ratings. sometimes the hitch is the weak link. i think a typical class V hitch can tow 14,000lb., but if you have a dually diesel PU with a 4:10 rear end you can probably tow twice that much. but i digress.

a class I has a tongue weight of 200lb i think. as long as your 4lb and your hitch don't outweigh that i think you're fine.

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Dan Empfield
aka Slowman

I wholeheartedly agree with what Dan wrote. In my response, I assume the ONLY thing you'd use the adaptor for..........is the bike rack.

I wouldn't trust putting 4 bikes on a 1 1/4" hitch. Not sure what rack you're planning on using, but the Yakima Holdup rack is advertised as like 90 lbs (49 for the Holdup, 42 for the +2 add-on). Plus, the 1 1/4 to 2" converter adds another 12-18". That's a lot of leveraged weight bouncing around back there. The tow hitch might be rated at 200lbs tongue weight, but that doesn't mean your vehicle can support that much weight. Not sure what a Prius can support, but that seems like a lot for that car. I'm certainly no expert on these things. I probably play it rather conservatively when it comes to things like this though.


I used a 2" Yakima Holdup (no +2 add on) on a Civic with the converter. It worked fine. The converter really makes the rack stick out off the back though and there was a lot of play in it. I used something like this to limit the movement. I can't remember what it was for, but I picked up basically the same thing from Home Depot for like $5.

i don't think it's quite that much. this is a foot long in total. the distance of the holes, on center, from each other is the extra leverage. the rack itself won't feel that. only the hitch.

now, maybe there's extra bounce. maybe that may make a difference.

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Dan Empfield
aka Slowman

You're probably right, I'm probably exaggerating the length of the extender. It's been a couple years since it was on there. It certainly felt like it was that long though! Clearance also was more of an issue getting in/out of driveways with gutters/dropoffs, even with the rack up and not in use.

 
If you don't want scratches on the bike then skip the type of rack that comes down on the top tube to hold the bike in place, it will scratch the hell out of the top tube. If you want to avoid scratches you need something like the Yakima Hold Up, the Thule T2 or the 1UP USA.

That said I would not put a 4 bike rack on a prius. The 4 bike racks stick out a long way from the back of the car and without the proper ground clearance it is going to scrape coming out of driveways or parking lots. We had a 3 bike Kuat on a Subaru Outback which is already much taller than a Prius and we had to be careful with dips in the road. Adding a 4th bike on that taller car would have scraped, it will be nasty on a Prius.

Then you have the issue of creating more leverage and reducing carrying capacity with the adapter you want to use. So now your carrying capacity is down to 150-175lbs instead of 200lbs. With the rack and 4 bikes you are going to be pushing it.

If you insist on going this route the 1UP USA is the best option. Rather than the rack going straight out it uses 1 at a time add ons and they "stadium" up from the first rack. This will help with the ground clearance issues and it is also the best rack in the business. But they recommend only putting up to 3 bikes on the 1 1/4" version. You can likely get away with 4 if they are all light bikes, but again, you are pushing it.

Perhaps two on the hitch and 2 on the roof is a better solution.

The 2-bike Kuat on my Prius was a nightmare on the highway, let alone when the wind was screaming across the prairie. No way in hell I'd carry four for any distance. Are you looking to use this in town, or to go to races hundreds of highway miles away?

And yes, the added sway and tail-wagging-dog was much worse than the... whatever on-trunk style I had at first. Much.

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The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

Well I think you guys have successfully talked out out of getting the 4 bike platform rack!

I'm using this guy:

http://www.softride.com/...ra_assist_bike_rack#


on a 1 1/4" hitch. Works fine. It actually comes with an adapter thingy that bolts onto the rack.

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Citizen of the world, former drunkard. Resident Traumatic Brain Injury advocate.

4 bikes? Even with the extended lever arm of the adapter, you are good to go if all you're loading are bikes. A 1 1/4" class II receiver hitch should be rated for a tongue weight of 350 lb. So, if you can carry the rack without busting a gut, that's 50 lbs. That leaves 300 lbs for 4 bikes. I think that you're OK unless you're hauling four battery assist bikes from a city rental rack. In DC, 70 pounds each! https://www.washingtonpost.com/...m_term=.3b2c0e83dcc4 (from DC Rainmaker's blog here: https://www.dcrainmaker.com/...w-nov-26th-2017.html). And even then, you are just at the limit....and these things are probably overdesigned by a factor of 2 (that's the engineer in me talking). Ride on.

If you do try it make sure it is one of the racks that the wheels sit in a cup and the arms come down on the wheels. Will keep your frame safer that way. I like the Saris SuperClamp. BTW, I would check the warranty on the rack to make sure that using the adapter does not void it, unless you do not care about something like that.

It's not just weight - as you say, weight ought to be ok. The Prius is designed to be very aerodynamic, of course, which means that a lot of air hits the bikes on the tray-style rack behind it. A bike (especially an aero bike) sideways is quite a parachute, and even a two-bike rack on the back of my Prius was a white-knuckle affair driving from Austin to Lubbock at Texas speeds (80mph limit) with the prairie wind. A similarly-light but much less-aero vehicle (Kia Soul?) would probably be a lot more pleasant for this task, let alone a bigger and heavier vehicle. A four-bike rack hanging off the back of a Prius would be like a giant slapping the rear of your car back and forth at random when the wind gusts, or a truck drives by.

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The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

Maybe, but the additional two bikes are in the wind shadow 'behind' the 1st two. I doubt that they will add much aero challenge over two bikes, unless I'm thinking of the bike geometry on the rack incorrectly. I have a hitch mounted rack where the bikes are oriented 90 degrees to the direction of vehicle travel (what I am imagining here). My vehicle is no Prius (an Infiniti sedan) - I don't notice and effects of wind on the bikes (one is typically a QR CD0.1, so lots of area in the wind) or on the vehicle. But this effect is surely very dependent on vehicle aero design...

^^ This, if you are carrying 4 bikes I assume you will have 4 people as well, I would imagine the car will squat. I would be more concerned about dragging or hitting the rack on the road than the hitch being able to handle the weight.
Here is a pic of a 1up rack with four bikes as you can see it sticks far back, not what I would consider ideal in a low clearance vehicle.

If you don´t want to carry bikes on the roof, have you considered a small utility trailer? you can probably pick one up for about the same or less than a 4 bike rack

There's a part to this that I think might be missing here. Go look under your Prius to see what that hitch is attached to, and then report back. Then crawl under your neighborhood F-150 and see what that hitch is attached to. I would have thought the same, that the hitch is rated fine for the "weight", but then factor in torque of a long arm rack on a wimpy little car body connection, and that's a ton of twisting on sheet metal, which I am certain your hitch is attached to. There is no body on frame "frame" down under there like with your SUV or pickups. It's sheet metal, and it deforms a lot, which explains the post about the bouncing. It's not the hitch that's twisting, it's the car body.

No way in bloody hell would I attach anything that large to any hitch not intended by the car manufacturer b carry such a load. There's a reason your Prius didn't come with a 2" hitch, and there's a reason a Subie Outback does. The Subie is built to handle it. Not pulling, not weight, but sheet metal deformation under your gas tank. It's not pretty when it's overloaded and it screams "impending failure" to me when I see those small hitch racks heavily loaded swaying around. Again, the rack AND the hitch are not bending. Your car is. My small .01.

Any anecdotal reports of "mine was fine" is similar to "my granny chain smoked until she was 100". It's just not a good idea, but you might get away with it.

Matt

You said what I was trying to say, only way better.

The Prius not only doesn't come with a 2" hitch, the manual specifically forbids towing. It's one thing to put a light receiver on it and put a light rack and a couple of light bikes, but a light trailer? Yikes. Remember that the Prius has a very specific transmission to deal with the hybrid system (and it's more unique than, say, Honda's hybrid transmission, which is why there's no manual Prius). This really seems like a bad idea.

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The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

That's the setup I have on my Subaru Impreza with my Thule hitch rack. It works fine. With my rack, it does draw out the backend quite a bit. On occasion, if I am not being careful and on a steep incline, it will sometimes scrape the pavement. Otherwise though, it's great. As others have mentioned, just don't try to tow your boat with it. Hitch racks are 1,000 x better than pulverizing your bikes into your garage while on the roof rack.

I was coming to write something similar. 1.25" hitches aren't always connected to something super strong in the car. The 30 seconds search of a Prius hitch install shows only one location for a multitude of receivers. I also didn't see any Class II receivers, but I didn't look hard. If there's any rust in that general area around the two bolts on either side of the receiver mount, I wouldn't even consider it. There's no backing plates and it is not uncommon to hear of a hitch receiver popping out of where it's attached due to the metal weakening (typically due to rust). You could have somebody that does basic welding add some reinforcement (that receiver will become a permanent piece of the car though) for around $100. This might be the way to go if you're absolutely sure you want to go this route.

Maybe it was covered here or you thought of it already, but forget the idea of any coverage for your bikes or racks if something unfortunately happened while having too many bikes on an extended (increased torque) arm. Load the heaviest bikes closest to the car.

Edit: It's still a bad idea. Maybe a roof rack for the +2 bikes would make the most sense.

You are a bit off on your weight ratings. Generally on a small car like a Prius the hitch receiver is going to be mounted to thin sheet metal under the car. I installed one on my wife's BMW 330CI convertible. Being a vert, a hitch was the only real option. The receiver is bolted directly through the spare tire well under the trunk. Not much strength for heavy loads. The hitch receiver clearly states 200lbs max tongue weight.

Class 1 Hitches are good for 2k lbs towing and 200lbs tongue weight.

Class 2 is good for 3500 towing or 300 tongue weight.

Class 3 gets into 2" receivers.

Looking at the options from Curt Manufacturing for a Prius, the only option they offer is a Class 1.

Also the rack is heavier than you think. The 2 bike version weighs in at 49lbs per Yakima Hold Up specs. They also claim 49lbs for the plus 2 attachment. So you are talking 100lbs for just the rack. Add 4 bikes at 20lbs each and you are at 180lbs. Now add the additional leverage of the longer arm from the adapter and you are at or above max capacity. Yakima also says no plus 2 attachment on the 1 1/4" rack, the plus 2 is only supposed to be used with a 2" rack. That coupled with the ground clearance issues is enough to consider this a bad idea for a Prius.

Sell the Prius - buy a Suburban - and carry anything and everything and everybody that you want.
Roadtrips are more fun with more people - 8 people, 8 bikes, +their gear - sorted.

My understanding is that the issue is the vibrations from the adaptor. KUAT specifically says not to use them in their owners manual and I believe FAQs.

Not sure about weight, but think that the adaptor also cuts your tongue weight capacity in half.

I tried it on my Maxima once - not with a four bike, but a two bike and an adaptor. I scraped everything, it was a real pain.

I don't know what year Prius the OP has, but apparently that changed last year:
https://www.digitaltrends.com/...d-towing-capability/