Bike rack drain

[Abhishek9]

Sorry for getting here late, we had to get the optional shim for our 3. The dl3 was fine one trip with 3 bikes, but fell off (at 5mph, on the first corner, thankfully!) with 4. With the shim in it feels much more solidly attached to the car, but I've not tried it out yet.

thanks for the reply. I'm not sure what you mean by the optional shim?

I've ordered the DL3 with extra carrier for 4th bike, as we have two light adult mountain bikes and two kids bikes

 

[Avendit]

One of these: https://www.roofbox.co.uk/scripts/r...s/095_611_atera_strada_clamp_adjustment_shim/

If the clamp handle gets past horizontal when you go to clamp it on, you'll need one. Seconds to fit, and leaves the handle at about 35 degrees on mine and feeling much more solidly connected to the car.

 

[MrBadger]

@Avendit link does not work here.

Is that shim needed because you have a small ball or is it fairly common to need and an 'atera thing'?

 

[Avendit]

sorry, tried to trim the link of what looked like tracking junk. obviously it was important:
https://www.roofbox.co.uk/scripts/rbvehsel4_tab.php/all-products/095_611_atera_strada_clamp_adjustment_shim/Qx@w,6M4PHS,ZGenkQvENtS2,3

 

[SSonnentag]

Hanging our 2 bikes off the back of our X seemed to only increase power consumption by 8% or so at freeway/expressway/interstate (and whatever the EU equivalent is called) speeds. I figure 10% to be safe. The drag increase for the same hitch scenario with a sedan would be much more drastic, but I don't have any firsthand numbers.

 

[Avendit]

Hanging our 2 bikes off the back of our X seemed to only increase power consumption by 8% or so at freeway/expressway/interstate (and whatever the EU equivalent is called) speeds. I figure 10% to be safe. The drag increase for the same hitch scenario with a sedan would be much more drastic, but I don't have any firsthand numbers.

My consumption was definitely offset by -actually-doing-the-speed-limit for a change. Tho that was a mix of mway, A-road at 60 and roadworks at 40 (damn average speed cams). Sitting on a motorway at 75+ will have a bigger impact.

 

[gangzoom]

Just done a very short trip in our X with a tow carrier bike rack and my eHybrid bike on the back.

ABRP suggested we would get home with 45%, got home with 46%. Driving at 65mph. Normally I 'beat' ABRP by a few % at 65mph, so I suspect the bike increased consumption by 5%ish?? Got a longer 150 mile trip soon so will report back.

 

[shuhockey]

M3LR trip last week of 80ish miles half motorway and half country road and we arrived with 3% more than anticipated at the start of the journey. This was with the tow bar carrier and three bikes. On the way back it was 2% more.

 

[Pmedlin63]

I would have thought that the bikes create a very turbulent airflow behind the vehicle and, consequently, low pressure behind the vehicle (because the air can no longer flow in a laminar manner around the vehicle body). This means there will be a pressure drag - high pressure in front and low pressure behind - which is why it is so inefficient.

Do you know if someone sells a bike cover which would clip into the back of the trunk lid creating an airfoil around the bikes?

 

[Avendit]

Do you know if someone sells a bike cover which would clip into the back of the trunk lid creating an airfoil around the bikes?

Its just not needed. I played with it in a simple fluid dynamic analysis program, and reality bears out that it doesn't make any real difference. For me, 4 bikes was more than made up for by slowing down by 5mph.

 

[Watts_Up]

Do you know if someone sells a bike cover which would clip into the back of the trunk lid creating an airfoil around the bikes?

If you need to travel for a long distance, try to remove the saddle and any baskets or accessories,
and if possible the front wheel using some fork attachments.