The BMW chopper build breakdown
Vložit
- čas přidán 6. 08. 2024
- While the bikes on its way to the USA I thought I would write a blog post engineeredtoslide.com/2022/06... and share a video on the construction process of the build, super excited to get to the Born Free Show and finally show off this piece of art.
- Auta a dopravní prostředky
One of the most beautifully designed builds on the planet, IMHO. Simple, eloquent, conservative, perfect balance of form & function. The less is more approach, isn't easy to pull off with skills like Nigels. It's easy to get carried away, showcasing fabrication skills, by dressing up parts that don't offer much more than aesthetic. To pull off those wheels, takes so much knowledge, to control the runout. Stainless steel can be very unforgiving, & make you pay for the smallest mistakes. You need laser precision & patience to pull out a wheel within a few thou. runout. SS does not like that heat & lets you no instantly. (wish he showed a clip of the wheel straight on, spinning with the dial indicator, to see where it ended up). It was one of the best builds at Born free that year. Handmade chassis, wheels, intake, exhaust, all pristine, topped with a classic wassail tank & a skinny lowbrow duck bill fender, to tie it all together, making it the perfect touch for that event. That carbon fiber spring for the girder was a nice touch too, especially on a chopper! I don't particularly like BMW, but I do love me some hand built 1-off choppers, & that it was! He couldn't have picked a better tire than that 18inch, MH drag slick, tucked tightly under the fender, to set the mood, Nigel is a straight up Legend! Would love to see his take on a vintage Harley platform.
Hey Nigel, love this aesthetics of this build.
Well done!
A true masterpiece, congrats Nigel.
To say I’m surprised would be a lie.
Can’t wait to see you bring home the win at BF13.
Please never stop building these inspirational works of art.
All the best
Thank you Mat, appreciate it mate.
Attention to detail is amazing; that carbon-fiber spring on that front end is sick! Even using the oem single side hub is pretty clever too! Hope you enjoy the the boxxer motor, pulling to the right when you goose it, and that radial car tire in the back.
Thank you, I have ridden a few boxxers in my time, good for overtaking in Australia haha
Awesome build. Your vision and creativity is to be admired.
Hearing it run and seeing you ride it should be the next chapter; keen to know how it handles and performs.
Thanks Scott, yes I have given it a good ride, that is posted over at BMW Australia's page, cheers mate.
It's a beautiful bike. The workmanship is exquisite, more like fine jewellery than industrial engineering. The welds are world class, and the wheels are both inspired and inspiring. Nothing but admiration for this achievement.
The only thing that I would do differently is the front suspension. The girder forks are magnificent, but personally I would not use carbon fibre for the spring.
Carbon fibre has many admirable qualities. It's incredibly light yet remarkably strong despite it's diminutive weight.
However, as it's a synthetic composite made of flexible woven mats of carbon fibre material impregnated with very strong resin, that's laid into or onto a mould of the required shape in a process similar to glass fibre construction, then placed inside special chambers under high heat and high pressure, which dissolves the resin throughout the carbon mat, prior to hardening as it cures, bonding & fusing them together, and permanently taking the required shape of the mould, the resulting material has properties & qualities that are extremely desirable, and others, not so much.
It's great strength to weight ratio works extremely well at resisting certain types of force, but due to the nature of it manufacture, it's light & strong, but also extremely brittle. That's why it's ideally used for items like the central tub in racing and exotic sports car construction. The carbon tub needs to be light, strong, & stiff to resist impacts, protect the driver in a crash, and be able to support the entire drivetrain, and complete front & rear end's bolted to it. All of which it does well.
One quality not so desirable for the tub is flexibility, which is fortunate as carbon fibre doesn't possess the qualities & properties usually synonymous & compatible with flexibility. It's very brittle laminate construction doesn't handle compression & deflection very well, like squeezing or bending forces from being placed in extreme pressure environments such as the deep sea, especially combined with high cyclic repetition which exacerbates the stress on the carbon fibre. It's the reason why the Titan Submersible imploded last year when the carbon fibre centre body of the submersible suffered a failure. Under the immense compression exerted on it over 3 km underwater, it probably started as a microscopic crack that quickly caused a delamination failure and subsequent collapse of the centre pressure vessel. Metal alloys are far better suited to these kinds of forces & applications, due to their more flexible & elastic nature, and ability to resist and absorb deformation & deflection in repeated cycles almost indefinitely using the right metal, or for a long time at least.
Conversely to a carbon tub in a racecar, springs require flexibility, elasticity, & resilience among other qualities. For which carbon fibre isn't ideal.
However, I'm no engineer or expert. Just an ex-motor mechanic with enough knowledge to get myself in trouble. I wouldn't presume to have your skill in fabrication or welding, and only make welds that look like that in my sleep. I may be wrong and the carbon works fine. But for my 2 cents worth, I'd prefer to use alloy steel. I can vaguely recall an exception, but it's why fibreglass has almost never been used to make leaf springs for cars, having similar properties to carbon fibre. But I suppose, if it cracks it's not catastrophic. Just ride home carefully and come up with an alternate design.
Beautiful bike, man.
Excelent build.
keen to see some rolling shots of this on the road
czcams.com/video/6lkgCU1MHt4/video.html BMW shared some video of it riding. Thanks.
Seeing you unbox the bike in person and hearing what you had planned back then, I never would have imagined it would end up like it has.
I don't know which is my favourite part, the magneto or wheels.
Goodluck at Born Free.
Thank you, it seems like a lifetime ago doesn't it, I wont lie, I didnt see it turning out like this back then either haha. Hope you're well mate. Still at BMW?
@@Engineeredtoslide yes, still here. Waiting for your next creation ;)
You said in the video that the bikes electrics are powered by a dewalt battery. Have you got any further information on this setup? I couldn’t see anything about it on your blog either.
It’s an 18v battery in a dock that plugs in under the bike, it only starts it’s and runs the lights. It wouldn’t work for a bike that needs power for its ignition.
@@Engineeredtoslide yeah I’m wanting to do a similar setup to my bike as what you have done here. I was just curious on more of the details behind the setup you have made :)
Very cool! It is super clean is it able to run? If so you did a great job hiding everything 👍
It sure does, you can checkout the video BMW did for it at czcams.com/video/WkbUhQ22LCk/video.html
Like assessing a boat in your backyard.
Let’s see how it RIDES (and sounds). Otherwise it’s just a sculpture in an art gallery.
czcams.com/video/6lkgCU1MHt4/video.html
Vende no Brasil?
Who made the carbon leaf spring?
I did with the help of a few key people, 3D printed mold, 12 layers of pre preg carbon, vac bagged and put in the oven for 12 hours before shaping, polishing and clear coating.
@@Engineeredtoslide that’s awesome. You’re not afraid to tackle anything. Did you do any calculations for the spring rate based on the number of plies and shape? Very interested in this
And the Sound.........nothing.......?