What Bike Rack has less drag: Roof Rack or Hitch Rack

[Blueboy]

I have the 1-UP platform Hitch rack on my MY. On a recent trip I used it to carry two road bikes. I knew it would create extra drag, but was shocked to see that my range was reduced by a third. Pretty consistently, for every mile I drove, my range went down by 1.5 miles. So my LR MY range went from over 300 miles to just above 200, requiring me to replan my trip's stops at superchargers. I typically drove between 72 and 76 MPH.

Now, a roof rack has the bikes positioned in the direction of travel, so that would suggest less drag than a hitch rack where they are positioned perpendicular to direction of travel. But in the hitch rack, they are in the rear, where I'd think they would have less drag.

I'd prefer not to get theoretical views. Does anyone have data on carrying bikes on top of their MY and what is the hit to the range that configuration? Other responses on the range you get when using hitch racks are also welcome.

 

[Watts_Up]

I have the 1-UP platform Hitch rack on my MY. On a recent trip I used it to carry two road bikes.
I knew it would create extra drag, but was shocked to see that my range was reduced by a third.
Pretty consistently, for every mile I drove, my range went down by 1.5 miles.
So my LR MY range went from over 300 miles to just above 200,
requiring me to replan my trip's stops at superchargers.
I typically drove between 72 and 76 MPH.

Now, a roof rack has the bikes positioned in the direction of travel,
so that would suggest less drag than a hitch rack where they are positioned perpendicular to direction of travel.
But in the hitch rack, they are in the rear, where I'd think they would have less drag.

I'd prefer not to get theoretical views. Does anyone have data on carrying bikes on top of their MY
and what is the hit to the range that configuration?
Other responses on the range you get when using hitch racks are also welcome.

For a long trip, I would recommend putting the bikes in the trunk,
even if you need to remove both wheels to save space.
This way you might be able to only fold half of the rear seat.

Otherwise, with your 1-UP platform Hitch rack can you try removing the front wheel,
this will remove a little bit of drag and would allow to recenter the bikes
to avoid the bike to extend outside of the car.

Another solution would be having the bike facing the road and as low as possible behind the car.

 

[Blueboy]

For a long trip, I would recommend putting the bikes in the trunk,
even if you need to remove both wheels to save space.
This way you might be able to only fold half of the rear seat.

Otherwise, with your 1-UP platform Hitch rack can you try removing the front wheel,
this will remove a little bit of drag and would allow to recenter the bikes
to avoid the bike to extend outside of the car.

Another solution would be having the bike facing the road and as low as possible behind the car.

Thanks for your suggestion. I may go with putting both bike in the rear cargo area on my next trip, but it's a pain to do that, and makes putting luggage there more difficult. Plus I'd have to take some care to not have the bikes damage each other, say with a blanket and padding between them. These are expensive, carbon fiber bikes.

Modern road bikes are moving toward having thru axles, so removing the wheels is a pain. I'm trying to have a setup where I don't have to do that.

You can't put the bike on a 1-Up platform rack with the front wheel removed. The whole idea is that the rack just grabs the bike by the tires.

The bikes don't extend outside the edges of the car.

 

[Watts_Up]

You can't put the bike on a 1-Up platform rack with the front wheel removed.
The whole idea is that the rack just grabs the bike by the tires.

Yes, I know this rack, you would need to add a fork holder, like the one used for pickup truck.

I imagine that removing the saddle would also improve a little bit the drag.

 

[Watts_Up]

@Blueboy , I imagine that you reviewed Bjørn Nyland video.
Your numbers are similar to those of a small trailer, but speed might explain it.

Tesla Model 3 roof box test
Tesla Model 3 test with small trailer​

BTW, do you have mountain bikes with large tubes and flat tires, or road bikes?

About carbon bikes, I have a Trek Émonda SL 6 Silver.

But I carry it in my trunk, I don't have a tow hitch. I have a roof rack, but I would not put a bike.
I previously hit the branch of a tree on a parking lot with my previous car and damaged the roof.

 

[Watts_Up]

Does anyone have data on carrying bikes on top of their MY and what is the hit to the range that configuration?
Other responses on the range you get when using hitch racks are also welcome.

@house9 - Unscientific roof rack efficiency test (Model 3)

Summary:
30 miles - mixed loop:
_2 miles - neighborhood (20 - 35)
12 miles - highway/freeway (65 - 80)
16 miles - road (45 - 65)

236 Wh/Mile - 00% - Stock
247 Wh/Mile - _5% - Tesla Roof Rack
264 Wh/Mile - 12% - Tesla Roof Rack w/Yakima Highroad
348 Wh/Mile - 47% - Tesla Roof Rack w/Yakima Highroad, 2 bikes

​

 

[Watts_Up]

@gidster99 - Range with Bike / Cycle rack fitted on tow bar / hitch

Summary:
72 miles 280 Wh/Mile - 00% - Avg Speed 60 MpH Max Speed 73 MpH - No Bikle Rack
72 miles 391 Wh/Mile - 40% - Avg Speed 48 MpH Max Speed 75 MpH - Bikle Rack with 3 Bikes plus Luggage

 

[Watts_Up]

Another solution would be having the bike facing the road and as low as possible behind the car:

I noticed the Atoc DraftMaster Hitch Bike Rack which could offer a good aerodynamics compromise:

Tandem version with Model X:

 

[Blueboy]

@Blueboy
BTW, do you have mountain bikes with large tubes and flat tires, or road bikes?

About carbon bikes, I have a Trek Émonda SL 6 Silver.

But I carry it in my trunk, I don't have a tow hitch. I have a roof rack, but I would not put a bike.
I previously hit the branch of a tree on a parking lot with my previous car and damaged the roof.

We only have road bikes. I have a Trek Domane, and my wife has the woman's equivalent, a Trek Silque bike.

Funny fact: Trek's high end bikes are the Emonda, the Domane, and the Madone. They are all permutations of the same six letters.

Thanks for all of the efficiency data. Did you get that from other posts within this forum, or your own tests?

 

[Watts_Up]

We only have road bikes. I have a Trek Domane, and my wife has the woman's equivalent, a Trek Silque bike.
Funny fact: Trek's high end bikes are the Emonda, the Domane, and the Madone.
They are all permutations of the same six letters. Thanks for all of the efficiency data.
Did you get that from other posts within this forum, or your own tests?

Yes funny names.

It was just some results from other TMC threads.
I didn't expect that bicycle drag would create about 40% of range losses.
This was a number reported for small trailers, but speed was much lower.
There was a thread with a trailer and some range comparisons, but I cannot find it.

I always carry my bike inside the car but I lose most of the rear seat.
If I have to use a bike rack for a long trip, I would remove at least the front wheel,
and may be the saddle and any bottle, bags, or accessories attached to the frame.

I wonder if the Drafmaster would provide some real improvement?
Another possibility for a long trip would be using a rear platform,
remove both wheels and place both bicycles horizontally and wrapped into a tarp.
It might be then more simple to put in the bikes in the trunk
and pile up all the baggage above and up to the roof.

Range and speed are quite important especially if you have passengers.
There is no ideal solution for caring bicycles which are light but very bulky.
I am worrisome putting a bike on the roof, from bad previous experience.
Anything placed behind the car can be an issue when using a SuperCharger

 

[2left]

@house9 - Unscientific roof rack efficiency test (Model 3)

Summary:
30 miles - mixed loop:
_2 miles - neighborhood (20 - 35)
12 miles - highway/freeway (65 - 80)
16 miles - road (45 - 65)

236 Wh/Mile - 00% - Stock
247 Wh/Mile - _5% - Tesla Roof Rack
264 Wh/Mile - 12% - Tesla Roof Rack w/Yakima Highroad
348 Wh/Mile - 47% - Tesla Roof Rack w/Yakima Highroad, 2 bikes

​

Your 349 Wh/mi for two bikes on the roof are right about in line with what I get with two bikes on my roof when I'm on the highway at 70-75 mph.

 

[DanDi58]

Reading this thread with interest, as I am getting the town hitch with my MY. Not sure which rack I'll get yet. But I mainly use my bikes locally, so I'm only driving for 30 minutes or so with them on the back; not too worried about the range hit at the moment. Although I could see myself taking them with us to Cape Cod every summer. I'll search around for threads on which bike racks are good (my wife and I have old Univega Rover road bikes). I'd prefer to pop on the hitch rack rather than put them inside as they are fairly heavy and my back ain't what it used to be. I do want a rack that is not crazy heavy but it doesn't have to hold more than our 2 bikes.

 

[djgarrett21]

Similar experience with my Yakima hitch mount rack (platform style). I was very surprised at the range hit as well on the freeway, probably ~30% reduction in range. I plan to take a few mountain bike trips, ~5 hour drive away (without charging) and the range hit is going to force me to change up my charging strategy significantly.

 

[Watts_Up]

Similar experience with my Yakima hitch mount rack (platform style).
I was very surprised at the range hit as well on the freeway, probably ~30% reduction in range.
I plan to take a few mountain bike trips, ~5 hour drive away (without charging)
and the range hit is going to force me to change up my charging strategy significantly.

Unless you really need the rear seat if you have passengers, spending time to put the bike inside your car would be the best option.

 

[Bill135]

We will be traveling from Harrisburg PA to FL this coming weekend with two bikes on back and a car full of luggage. I am Planning on 360W/mi and keeping speed under 70 mph. Weather should be ok as it is supposed to warm up on Saturday.

 

[djgarrett21]

Unless you really need the rear seat if you have passengers, spending time to put the bike inside your car would be the best option.

Agreed if it is a single road bike - definitely worth it. Mountain bike(s) covered in dirt/mud is a different story

 

[DaveORD]

Agreed if it is a single road bike - definitely worth it. Mountain bike(s) covered in dirt/mud is a different story

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+
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problem solved...

 

[Blueboy]

... I'll search around for threads on which bike racks are good (my wife and I have old Univega Rover road bikes). I'd prefer to pop on the hitch rack rather than put them inside as they are fairly heavy and my back ain't what it used to be. I do want a rack that is not crazy heavy but it doesn't have to hold more than our 2 bikes.

I strongly recommend a platform rack. For me the choice came down to the 1-UP rack and the Kuat Sherpa rack. I went with the 1-UP rack as they are modular, so can be configured to hold 1, 2, or 3 bikes. But the Kuat Sherpa rack is lighter that the 1-UP configured for 2 bikes. It holds exactly two bikes (no modular expansion). It looks to be quite easy to take on and offf the car. For either of these racks, it is very easy to put the bikes on the rack or to take them off. And the bikes are very secure, and since the racks only grab the tires, there's no potential to scratch the bikes.

 

[Rshephorse]

hitch rack will be less wind resistance than rooftop. especially when 'not used'.
For longer faster trips we put the bikes in the car- if there's only two of you it's easy.
I thinking that there would be a way to put bikes without tires on the 1Up rack I have, rest a fork or dropout in the center of the tray, stabilize with the swing-arm and shore-up with a few webbing straps. This would really reduce the bikes exposure to the wind and keep it down in the slipstream of the car.

 

[Bill135]

We just completed our trip to FL from Harrisburg with two bikes on Thule rack with the front tires off and a car full of luggage. Temperatures on departure were in the low 30s with no wind. Car was charged to 100% and warmed up. I added the last few % while we were getting ready to leave. We traveled I-81 to Waynesboro, VA, Rt 29 to Charlotte, NC and I-77 to Columbia SC. I generally drove at the speed limit. W/mi ranged from 330 to 380 with an average of around 360.

The next day we traveled south on I-26 to I-95 to Rt-301 to Ocala and I -75 South to Venice FL. Traffic was heavy with lots of accidents. Autopilot is a godsend. Again drove right around the Speed limit or slightly above. Even at 75 mph I was going slower then a majority of the traffic. People are nuts and take way too many chances. Even though I was going faster then the previous day my W/mile was lower ranging from 310-360 W/mile because of higher temps and it’s flat.

For the entire trip I averaged 341/mile for 1172 miles. The low average is due to stop and go traffic and getting off the interstate for about 200 miles of the trip.

As a comparison I have driven back and forth from Harrisburg to Pittsburgh recently and W/mile have ranged from 240-360/ depending how cold it was. One trip with temps in the 20s with a 10 mile headwind w/mile was 360 whereas on the return trip with temps in the low 50s and no wind the W/mile was 240.

So all that being said i would estimate that bike rack with two bikes adds about 50-80W/mile. The biggest determinant of how much energy the car will use are in order: speed, temperature and wind. When you have a bike rack on the car the effects are amplified.

We had a good trip, although it took, about 1-2 hours longer per travel day when compared to the same tip in an ICE vehicle. We stopped to charge 4 times the first day and 5 times the second day. The biggest PIA was having to SC in Columbia for 40 min to go from 15%-95% after dropping my wife off at the hotel. I needed a full battery for the 154 mile run to Hardeeville, SC.