Creating a motorcycle rear side rack, need opinions

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Creating a motorcycle rear side rack, need opinions

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bkadv	b bkadv posted 7 Years Ago HOT Topic Details
b Group: Forum Members Posts: 5, Visits: 37	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. Edited 7 Years Ago by bkadv
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Steve Broad	Steve Broad posted 7 Years Ago HOT Post Details
Group: Forum Members Posts: 408, Visits: 4.1K	+x Hanaldo - 8/15/2018 1:54:34 PM Because the benefit of an aramid is its resistance to break, not necessarily its flexibility. Aramids are still stiff, they just aren't as stiff as carbon. Generally in a hybrid layup, you would use the carbon on the outer most layers and the area aramids internally. Bkadv, I completely agree with Oekmont. If you do go ahead with it, lose the PET core - your core is the PVC, you wouldn't then wrap that with another core (PET core is no where near pliable enough for this anyway). Your layup is otherwise solid. I wouldn't make the skins any thicker than that as it will become a bit of a danger in an accident. That layup is plenty stiff enough for everyday handling etc. Steve, I'd be interested to know what you are basing your opinion of composites and fasteners on? My experience is mostly in motorsport, and some in boats and gliders - all of which have quite demanding fastener applications. They do take special consideration, but you just do it properly, there's no reason I would look at something and say that cant be done with composites because it needs to be bolted somewhere. The aramid won't stop the carbon from braking once it exceeds its elastic limit (not the right term but, hopefully, you know what I mean :-) ) I had originally planned to build the front clip of my car using aramid and carbon but, after talking to various experts, the only advantage was that in the event of a crash it would be easier to pick up the pieces compared to a wholly carbon clip :-) I needed the stiffness so went with carbon only. AFAIAW the OP is new to composites. Adding fasteners to composites has to be done properly otherwise they will simply pop off at some time in the future, especially if under stress which they will be on a bike. I am looking at this from a practical perspective as opposed the expert/ideal one as I am just someone mudding along on his own in the real world and can only comment on my own experiences and successes/failures.
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