Renovation and aerodynamic improvement of a BPW closed trailer

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Renovation and aerodynamic improvement of a BPW closed trailer




by Christophe » 27/08/22, 20:11

I have just bought an old used closed BPW trailer (according to the plate it would date from...1980???). It's a German manufacture ... it's obviously sturdy without being too heavy.

trailer_bpw.jpg


trailer_bpw_2.jpg


The chassis is still perfect despite the years... on the other hand, I don't know if there is damping and if there is, it is weak (it doesn't move too much when shaking it...)... but it looks like torsion arms right? Advice to specialists? : Shock: : Shock: : Shock:

trailer_bpw_6.jpg
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I just weighed it, it weighs about 290 kg empty (There's 20 kg more on the drawbar, not photographed, and the ground was not 100% flat, hence the asymmetry) and the PTAC is 650 kg...which leaves 360 kg of payload, much more than I need (but hey, the kg goes quickly, huh!!)

trailer_bpw_3.jpg
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trailer_bpw_4.jpg
trailer_bpw_4.jpg (345.05 KiB) Viewed 3695 times


trailer_bpw_5.jpg


The 10 mm plywood body would deserve a nice renovation... also to make it more aerodynamic!

The idea is therefore to create an aerodynamic cylindrical surface on the front part and to extend it on the sides...for the first stage of the renovation... 8)

First question : what material to use? It must be light, flexible and resistant to bad weather and wind...

I can easily weld a chassis on the front part to put this new, more aerodynamic fairing.

I thought cold of aluminum sheet...

In 0.5 mm there would currently be around 100€ for the outline of the trailer, but is 0.5 mm enough?

In terms of weight, in 0.5mm it will be around 13 kg, in 1 mm around 26 kg...just for the outline...with the roof it would probably be a good 30 kg...and I have to other things to renovate...(in the idea of ​​this aerodynamic fairing, I keep the side walls)

The kg goes quickly...

There you go, thanks for your advice guys! It's the economic exercise of the moment (I saw a few Barbot trailers during my research: it's beautiful but it's completely overpriced and the chassis are certainly not of the quality of this old BPW.. .)

Edit additions October 2022, 2 months later

A comparative study of trailer aerodynamics was carried out from this page: self-construction-and-do-it-yourself/renovation-and-aerodynamic-improvement-of-a-closed-trailer-bpw-t17276-640.html

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And the appearance of the trailer optimized at the end of October 2022:

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Macro
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by Macro » 27/08/22, 20:23

Badly locked... Your axle whose suspension works by deformation of rubber silenbloc is crushed...

Then...Your trailer has a GVW of 650kg...Do you have a gray card? because the Germans have a different legislation than us

The aerodynamics of a trailer : Cheesy: : Cheesy: : Cheesy: it can only be reconsidered on the complete set... There you are tackling a heavy project for results... that you will not be able to quantify...
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by Macro » 27/08/22, 20:55

Here are the dimensions that your suspension arms should have when empty
https://www.code-remorques.fr/essieu-de ... 00047.html
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by Christophe » 27/08/22, 21:01

Macro wrote:Badly locked... Your axle whose suspension works by deformation of rubber silenbloc is crushed...


Ah that's why they are hard : Mrgreen: .... Well, that can be fixed, right?

Macro wrote:Then...Your trailer has a GVW of 650kg...Do you have a gray card? because the Germans have a different legislation than us


Belgians too: https://assurance.be/immatriculer-caravane-remorque/

Macro wrote:The aerodynamics of a trailer : Cheesy: : Cheesy: : Cheesy: it can only be reconsidered on the complete set... There you are tackling a heavy project for results... that you will not be able to quantify...


Pfff defeatist you don't know my perseverance and my aeronautical talents 8) 8) 8) ...Here's a gift: https://dragonfly-paramotor.fr/ (it is precisely for this project that I bought this...old stuff...but carrying my Dragonfly in it will be a task...hence the necessary renovation!)
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by GuyGadeboisTheBack » 27/08/22, 21:02

A silent block cannot be repaired, it can be changed.
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by Christophe » 27/08/22, 21:04

GuyGadeboisLeRetour wrote:A silent block cannot be repaired, it can be changed.


I finally ... : Shock: : Shock: : Shock:
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by GuyGadeboisTheBack » 27/08/22, 21:07

Gaston, get out of this body! : Mrgreen:
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by Macro » 27/08/22, 21:08

Well... I would tell you to play something like an inflatable structure between the car and the trailer because automatically you will have the turbulence of the "drag" of the car which will rush into the intermediate space.. Unless your towing vehicle is a truck..
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by GuyGadeboisTheBack » 27/08/22, 21:11

I have a friend who had "aerodynamicized" his trailer with a bamboo structure covered with truck tarpaulin, adjusted of course. Removable, lightweight, inexpensive.
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Re: Renovation and aerodynamic improvement of a BPW closed trailer




by Christophe » 27/08/22, 21:14

Obviously Macro, the overall drag will be increased in all cases with a trailer but there is nothing worse than a flat front surface, especially in the wake of a car! : Shock: : Shock: : Shock:

Take a look at the design of modern barbot trailers...it's not as bad as my "wall" huh...

barbot.jpg
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