Rear bumper build

[stumog]

I need to ask some questions on details of making my own rear bumper so I thought I would start a thread to keep it all together.

I am not great a planning so will be cutting and shutting as I go to make it look right and hopfully strong enough.
Dont really need something super tough as only a expedtion truck but we will see.

Would like to bring the s7des out to give the wheel arches a bit of protection. Lots of the aftermarket ones dont really do this. Then going to add some brackets to get the wings supported to the chassis.

Mainly going to be made from a piece of folder steel into a channel. Now is 3mm with some gussets going to be strong enough? It will have a swing spare wheel and may be some jerry cans on the other side but a bit latter on.

Stay tuned
Stu

 

[MikesVX80]

Dont really need something super tough as only a expedtion truck but we will see.

It will have a swing spare wheel and may be some jerry cans on the other side but a bit latter on.

I think these two sentences kinda contradict each other! To support a spare wheel + carrier (~40kg?) and 2x jerry cans of fuel (~50kg?) you need a pretty substantial bumper to support 100kg+ of load, particularly in expedition use. Imagine the forces on those parts if you hit a big hollow on a fast bit of road could easily be several times the 'static weight' of those items.

Without doing any calculations or knowing your proposed design I would say 3mm will be too thin - using box section might help, but I would look at what the aftermarket companies do and benchmark those as a start point.

 

[pberrey]

Stu, I think my 4x4 Specialist front bumper uses a mixture of 3 and 5mm steel plate. That keeps the weight down to 70kg if i remember correctly without compromising strength. As far as i know the same is true for the rear bumpers but that approach is something the have R&D'd over time and the skill is in using 5mm only where it counts.

If i were building (ok spec'ing) my own bumpers I would go 5mm everywhere and not worry about the extra 30-40kg I was dragging around.

Let's not forget that the primary requirement for any bumper on an overland vehicle is that it looks cool. The rest is a bonus but its the sort of thing i would do it right and be happy that if i catch the odd rock at the wrong angle its not going to bend/twist.

Rgds
Paul