My carbon Milan 4.2 build
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Since I was going to laminate the frame for that service cover, I also wanted to repair the tear in the body front right wheel.
I may actually have caused this myself, when I bought it and we tried to maneuver the bike into my camper van
I first used a saw to cut along the crack, because you need to relieve any remaining stresses, or else your repair will eventually fail too.
Then I sanded the inside, and laminated a layer of aramide-hybride UD (transverse over the tear) and then covered that with plain carbon twill weave.
Then, I rotated the body right side up and laid a layer of carbon twill over the drawn cut pattern. Noted that I first taped the body so the epoxy will not adhere to the body.
Then, I did 2 layers of aramid -hybrid UD (or actually: I folded over -lengthwise- a wide band of it).
And covered again in regular twill carbon.
The reason for the additional twill is that UD is only strong in 1 direction, and I don't want this border to crack when an edge get bumped.
The reason for the aramid is that it adds both thickness to the frame and safety: crash protection.
Edit, I'm fighting the formatting here, it's worse than MS Word!
I may actually have caused this myself, when I bought it and we tried to maneuver the bike into my camper van
I first used a saw to cut along the crack, because you need to relieve any remaining stresses, or else your repair will eventually fail too.
Then I sanded the inside, and laminated a layer of aramide-hybride UD (transverse over the tear) and then covered that with plain carbon twill weave.
Then, I rotated the body right side up and laid a layer of carbon twill over the drawn cut pattern. Noted that I first taped the body so the epoxy will not adhere to the body.
Then, I did 2 layers of aramid -hybrid UD (or actually: I folded over -lengthwise- a wide band of it).
And covered again in regular twill carbon.
The reason for the additional twill is that UD is only strong in 1 direction, and I don't want this border to crack when an edge get bumped.
The reason for the aramid is that it adds both thickness to the frame and safety: crash protection.
Edit, I'm fighting the formatting here, it's worse than MS Word!
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Just upload the photos directly to the forum and put them fullsize into your text and everything is fine.
Nice work, looking forward to the finished 4.2 as it is a very spezial bike.
Nice work, looking forward to the finished 4.2 as it is a very spezial bike.
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When I was holding the part, I got a little nervous, wondered if it would be strong enough.
But I think it's ok.
With 100 KG of sideload, on a single plate, it's approaching the limit of this alloy
And that's what you would get when doing 1G sideways with a heavy (adult, male) passenger. Something I'm not hoping to do (for the sake of wellbeing of the passenger).
But I think it's ok.
With 100 KG of sideload, on a single plate, it's approaching the limit of this alloy
And that's what you would get when doing 1G sideways with a heavy (adult, male) passenger. Something I'm not hoping to do (for the sake of wellbeing of the passenger).
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I cant stop looking at this mount <3
What about dynamic load? Like hitting a pothole, bombing over train tracks, etc...When I was holding the part, I got a little nervous, wondered if it would be strong enough.
But I think it's ok.
With 100 KG of sideload, on a single plate, it's approaching the limit of this alloy
And that's what you would get when doing 1G sideways with a heavy (adult, male) passenger. Something I'm not hoping to do (for the sake of wellbeing of the passenger).
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Those are almost mostly vertical. And suspension and flex in wheel + swingarm flatten the highest peak loads. They get filtered, or 'spread out over time' before reaching the swingarm bearings.
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Weight and other vertical shocks, caused by bumps/potholes hardly affect the swingarm bearing, by the way. Those loads travel up to the suspension struts, of which I plan to mount 2 (1 on either side), and quite close to the wheel axle (which is why the swingarm bearings are hardly loaded).
Hard cornering is the most challenging load-case for these mounting plates, as then the plate gets loaded perpendicular, the pivot tries to bend the plate.
Hard cornering is the most challenging load-case for these mounting plates, as then the plate gets loaded perpendicular, the pivot tries to bend the plate.
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I was thinking about something like this:
The black 3dprints are very thin and hollow, only act as a template/mould.
I would laminate over them, onto the body, and over the 'combs' of the aluminum (first 1 layer of glass, to prevent galvanic corrosion).
By making such a 'bent wall', you can still reach the M8 swingarm pivot fastener with a spanner or ratchet.
The black 3dprints are very thin and hollow, only act as a template/mould.
I would laminate over them, onto the body, and over the 'combs' of the aluminum (first 1 layer of glass, to prevent galvanic corrosion).
By making such a 'bent wall', you can still reach the M8 swingarm pivot fastener with a spanner or ratchet.
I assume the place and size of the access hole affects the stiffness of the body. Can you enlighten us a bit on the trade-offs?This seems the correct size, to me
Because it's next to the bumps, any rain will run down the sides and not into the bike.
And the (internal) border -needed to fix the cover onto afterwards- will not reduce available internal pedaling space.
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Sure, the body will lose some stiffness.
That is why I did laminate quite a thick border (using the aramid-hybrid to give it thickness), hoping to restore at least some of what will be lost.
But maybe you remember this post, which shows what a HUGE hole I cut in my QV?
I didn't notice any change in how it handles. And people that have ridden with me, know I stress-test the handling of my bikes
What would happen if your rear breaks out and would hit eg the curb?When I was holding the part, I got a little nervous, wondered if it would be strong enough.
But I think it's ok.
With 100 KG of sideload, on a single plate, it's approaching the limit of this alloy
And that's what you would get when doing 1G sideways with a heavy (adult, male) passenger. Something I'm not hoping to do (for the sake of wellbeing of the passenger).
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Sliding sideways into a curb will probably wreck the body (the curb will probably not even hit the wheel).
With such a crash, replacing a bent plate is something I can then take along when repairing the rest of the bike
Most cars also need a repair, after a failed imitation of Colin McRae..
I will not design and construct something that can handle any crash, as the bike would become extremely heavy and lose all of its agility (as fas it has any already!) and fun.
Please also note that I'm not planning on installing some illegal high-power motor.
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Can you explain a bit more about this design? I don't understand why you make such a thin and high construct. I would expect it much easier and stronger if it would be as small as possible and attaching directly to the side wall and/or floor.I was thinking about something like this:
The black 3dprints are very thin and hollow, only act as a template/mould.
I would laminate over them, onto the body, and over the 'combs' of the aluminum (first 1 layer of glass, to prevent galvanic corrosion).
By making such a 'bent wall', you can still reach the M8 swingarm pivot fastener with a spanner or ratchet.
Ah yes I was thinking quattrevelo where sideway slips are more common. With 1 wheel at the back, things go south much quicker .Sliding sideways into a curb will probably wreck the body (the curb will probably not even hit the wheel).
With such a crash, replacing a bent plate is something I can then take along when repairing the rest of the bike
Most cars also need a repair, after a failed imitation of Colin McRae..
I will not design and construct something that can handle any crash, as the bike would become extremely heavy and lose all of its agility (as fas it has any already!) and fun.
Please also note that I'm not planing on installing some illegal high-power motor.