Hello all i just finished a tour around the world on this motorcycle. I want to replace things and make this bike lighter overall. I want to start with the rack and work my way later to other projects on this bike.

I want to make a side pannier rack. I already have a custom made one but its steel and heavy.

The characteristics I am looking for in this project are: Great in tension(pulling on rack), impact resistance, abrasion resistance and lightweight 

this is a mock up using MS paint along with a picture included of my motorcycle with the steel pannier rack



I am thinking of getting it in 10mm thickness
https://www.easycomposites.co.uk/rigid-foams/easycell75g-infusion-grooved-closed-cell-pvc-foam-core.html

shape up the mock up in my MS paint drawing with this easycell75G, connect pieces with glue, sand around the edges to get it into circular/tube shape. 

then cover it all with 1 layer of Kevlar, 1 layer of 3D core and final outlayer of Carbon 2/2 twill 200g

Around the bolt plates in the picture, I will reinforce it with 1x small piece kevlar around the bolt hole and 2 extra layers of carbon fiber. So when bike crashes, the bolted joints to the frame of the motorcycle doesnt snap easily.

What do you think? can i get feedback on this plan. Maybe I can use some other core?, use different layer?

Thank you ,

- BkADV

i am fine with a total thickness of around 0.75 inches.

Hi. You went around the world on that bike? Wow!

With the vibration this rack has to endure, I am not sure that composites are the way to go. You can't bolt directly to carbon,, aramid etc, especially if a foam core is involved, so metal inserts have to be added. With the vibration they will have to cope with I would not be confident that they would hold up for long.

I love composites and have used them on my drag car project wherever possible. However, it is horses for courses and I wouldn't use them on your project. If you are looking to save weight I would simply remake it in titanium, saving around 43%. I doubt that a composite version would weight much less.

On a world tour, there are factors that are more important than weight. You could make a lighter composite structure (I would advice in rethinking the whole design for that, as this was really made with steel construction in mind) that would last forever in normal use. However, one unlucky accident and you are stuck in whateveristan without a rack. It is not that composites can't handle rough use, it's that there is no bending back, no quick welding in some backyard workshop. For the second reason, titan would be a suboptimal choice, too.

If you really want a composite solution:
-composites like flowing forms to maximise their performance.
-skinning a core with a core material doesn't make much sense
-the outer skin over the core should be thicker than a single layer, so that not ever scratch could cut the whole skin, resulting in potential failure.

Don't often disagree with Oekmont, but I do this time. I don't consider that composites are the best way forward here. The inherent weakness is in the fastenings. Titanium is used in race cars and aircraft so perfectly suitable for your application, subject to choosing the correct grade.

I do agree, however, that the weight saving would be outweighed by the maintenance/repair problems in the field. I doubt that many backstreet workshops stock titanium filler rods or epoxy repair resin :-)

okemont isnt really recommending composites just highlighting how it could be done. The first paragraph highlights why he wouldnt recommend composites.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Maybe it did not came over as intended.
I do not consider composites as an optimal choice. But not because of the fasteners. Read yourself into that. There are plenty of good metallic insert like solutions in various designs that will last forever. Done right, this is no problem at all.
My problem is that if a composite part fails the function fails as well. Steel usually just bends. Bend it back and you are on the road again. And if it breaks, you can find someone who can do a quick repair. To find someone to weld titan will be much, much harder. And you will most likely disagree, but titan is not quite as durable as steel, especially for long time dynamic loads and unplanned load peaks (accidents). Most medias will tell you otherwise, calling titan a wonder metal, but I studied 6 semesters metallic material science, I know quite a lot about that. That said, the sentence before is a rough summary, as steel isn't equal to steel, and the same is true for titan.
In most cases (speaking of bigger structures with few functional faces) the carbon structure will be lighter than a steel or titan one. But weight isn't everything.

Thank you for all the responses

I just want to clarify, i already finished my tour.

Second, the rack is not important. If it breaks, my luggage can be adapted to without racks. I also rather not have metal panniers bending into my exhaust system. Too many rich people with BMW GS and metal work. 1 simple dent on their outer protection simply dents into their engine/pipes and causes much more damage than it needs to be. .that is why we have composite helmets for our head

I dont need bodywork, racks and aux fuel to survive. If it breaks, im fine with that... I was already fine with losing my whole motorcycle in east Russia as long as i lived.

I have gained lots of experience with my 40k km trip.

Isnt carbonfiber or rather composites much better in vibration prone areas? I hate the sound of rattling of metal skid plates and metal pannier/racks in off road and extremely bad roads.

My goal with this motorcycle now is, to put in an new engine, redo suspension, body work(in carbon and kevlar), lights. Create a carbon fiber fuel tank for Aux fuel((not main tank) and composite side and rear pannier rack. Less weight.

My future plans for traveling on this bike is short trips to china/india/pakistan/tajik/krygz/uzbek. TAT in america, some bits of TET in EU. So nothing serious, I am comfortable in these regions in terms of language and getting around.

I already did the big trip



in Mongolia ^^

If you are just pootling about then a composite rack with built in fasteners will work fine. Likewise, titanium will work as well.

Oekmont - We will have to agree to disagree re the fragility of fasteners in carbon and the frailty of titanium :-)

Why are you mixing aramid with carbon? By sandwiching the aramid within carbon you lose the flexibility of the aramid.