Thanks to [Radical Brad] for writing in to let us know about his recent project, building a street racing bike from square tubing and old bike parts.
In this 50 minute video [Radical Brad] takes us through the process of building the Marauder v2, a street racing LowRacer. The entire build was done over a few weekends using only an AC welder, angle grinder, and basic hand tools you probably have in the garage.
The entire rear section of the Marauder is made from an unmodified stock rear triangle from a typical suspension mountain bike. The frame is made from 1.5″ mild steel square tubing with 1/16″ wall thickness, which is called “16 gauge tubing”.
[Radical Brad] runs you through the process of welding the pieces together at the appropriate angles along with some tips about how to clamp everything in place while you work on it. After completing the rear end he proceeds to the front end which uses the fork from the front of the old bike. A temporary seat is fashioned from some wooden boards joined together with hinges. Then the steering system is installed. Then the chains and pulleys for the motion system. Then the seat is finalized, and after a coat of paint, and installing some brakes, we’re done!
If you’re interested in projects for old bike parts you might like to check out Juice-Spewing Wind Turbine Bootstrapped From Bike Parts and Odd-Looking Mini EV Yard Tractor Is Made From Plywood And Bike Parts.
A mate built something like this about 30 years ago….
I could never get the hang of recumbents, so I’m stuck on my slow upright bikes (doubly slow, since I don’t ride as much as I used to…)
I wish they would have mentioned that this is an Atomic Zombie build. They sell plans for all kinds of strange and wonderful bikes built from existing bike frames and hardware store parts that you can build using standard hand tools.
https://www.atomiczombie.com/content/plans/marauder_lowracer/marauder_lowracer.htm
There’s some awesome bikes over there, thanks for the link!
Thanks for the link to my site!
I am putting my DIY builds up on my YouTube Channel now.
Will try to do at least one per month, but in the summer I am busy on the farm!
CHeers!
Radical Brad – AKA: AtomicZOmbie / ChopZone!
And the Marauder is in the ‘Bike builder’s Bonanza’ book https://books.google.com/books/about/Atomic_Zombie_s_Bicycle_Builder_s_Bonanz.html?id=A3WMA18kHJUC …published in 2003.
I’ve given copies of this book to so many people over the years. It really is amazing how many unusual designs and geometries he/they show off, all built from EMT and salvaged steel bikes.
Wow, brings me back!
I ended up doing that book after being contacted by McGraw Hill when they seen my world record tall bike. Fun days!
https://chopzone.com/about.htm
Thanks for your support.
Brad
Call me old but all I see is neck pain
I have ridden and built recumbent bikes and have a few observations.
I never understood the idea of putting a steering tube between your legs. There are two problems with it. First, you have to hold your hands up there, which pretty quickly gets tiring. Second, and more importantly, if you crash the bike, that tube is going to end up in the place you want it the least. Steering under the seat is much more comfortable (but I get it- this bike wasn’t made for comfort, mostly “cool”), as your hands just fall onto the handlebars.
The super long wheelbase is going to make for wobbly steering at low speeds, especially going up hill. The problem is the steering feels “delayed”. You turn the handlebars and it takes a while for the bike to respond, so you turn further. The bike catches up with your steering input and now you have to turn the other way because you turned too far. It makes for a wobbly ride at low speeds.
The super long chain is going to try to jump off the chainrings if you pedal while turning the bike at moderate speed. The mass of the chain wants to keep going forward in a straight line and you’re steering the bike away from that line. It’s better to keep chains shorter – break the chain up and put in a mid-drive gear.
Super low bikes like this are invisible to cars.
Transporting this bike somewhere you can ride it safely is going to be a problem.
Here’s mine: https://drmrehorst.blogspot.com/2018/10/diy-carbon-fiber-full-suspension.html
That was a good comment with useful info
One thing though, you can buy flexible thin flagpoles with an orange flag that sticks up high for children’s bikes but also this kind of low riding vehicle, so I would advise to at least get one of those. After all, on quiet roads the lone driver might expect a low bike even less.
This has been on my list to build for a long time. My inexperienced eye agree with underseat steering or a mechanism that would result in podracer type steering. and the mid-drive gear. There are also lighted buggy whips available. This being hackaday, I suspect a regular fishing pole or two with a LED strings on it could be used for much cheaper.
FWIW my experience riding with people who have low-rider recumbents is that they look so weird, drivers see them from much further away than they see me. I regularly see pedestrians stop and point when they see a recumbent. They don’t fit in our pattern library so they stand out.
I wouldn’t ride a low recumbent in the driving lane in rush hour traffic. But that sucks on a standard upright too.
And in my experience I’ve had times I almost overlooked them while riding a bicycle myself..
Since they disappear in so many traffic situations, cars and bushes and all kind of objects as well as groups of cyclists hide them, and especially in corners. And in fact you might simply literally overlook them while looking out for regular traffic.
I’d not object to the steering location myself, if you crash the bike you already screwed up and are probably going to be injured at least with minor bruising etc no matter where the steering is. And with under seat steering you can’t use your arms to resist going forwards over the top or into the handlebars nearly as much, and as with all recumbents you can’t just stand up and step off the bike as it goes wrong or roll off the bike etc – they are just not as easy to cushion your impact with the ground because of the body position (though with really low recumbents like this one the converse is you also don’t fall very far either).
Not ridden one like this, but I can’t see how this would get uncomfortable or really be tiring – its barely raising your arms at all! I’d also suggest it is a more versatile position as anybody can sit that little bit more upright, pad with an extra cushion or raise/lower the handlebars to put them in a comfortable enough location to give this bike a go. Where under your legs doesn’t have that same easy flexibility and I’m not entirely sure everyone would even be able to reach – some folks have long torsos compared to their arm length, and others arms so long the position you have placed yours would be uncomfortable most likely..
I suspect that ‘wobbly steering’ wouldn’t really be an issue either – just got to learn how that bike behaves and retrain your expectations.
I do however mostly agree with you, and like the design you went with. I especially agree on this thing being impossible to use safely on public roads. If you are going to have a lower more aerodynamic pedal powered object on the roads it probably needs to be a velomobile style as they usually have a taller fin on the body work with some lights etc to really be visible.
Years ago I was testing a coaster brake hub as my front hub brake on my self-made short wheel base recumbent. (The cable from the brake lever pulled a short section of chain wrapped around the sprocket against a return spring.) While cruising along a section of pavement, the hub locked unexpectedly and launched me off the front. Since I use underseat steering, I just ran forward away from the now vertical bike. Indeed, one foot was still in the toe straps with the pedal on the ground. I stopped after a few steps and looked back to watch the bike topple sideways. The chainrings left some gouges in the hot tarmac. What excitement! I changed the front brakes very soon after. But the incident proved to me the ease with which an emergency front dismount was possible.
+oO
Interesting, actually managing to go over so straight that you can stand up with a recumbent is something I’ve never seen before, always seems to roll too much as soon as control is lost. I’m guessing yours was fairly short wheelbase and high rider position (so high COM) to make it possible, unlike this thing – as usually the fact you are so horizontal and pretty much stay that way as you fall with the longer wheelbase and usual pretty low COM means it will twist rather than pitch up enough to get your legs underneath you. But so many ways you can come off and an even wilder range of designs for recumbent bikes.
It might be vastly different in the US, but round here, car drivers are very cognizant of potholes or debris on the road, so it’s pretty much impossible to miss a bicycle, even if it’s low.
Flags don’t do anything at all: they will just impact aerodynamics while being far too small to recognize quickly at speed. The reason this works on some trailers or children’s bikes is that a trailer is pulled by a large and expected upright bicycle, so you just need to get the extra information that this is a somewhat long vehicle. As for children’s bikes, they are just very slow. Riding at speed, i.e. let’s say about 30 km/h / 20 mph, which is pretty comfortable for a recumbent, these small flags will be nigh invisible.
Long wheelbase recumbents have fallen out of favour (for good reason), but so have intermediate gears. Long chains really are less of a problem than you make it out to be with modern chains and chainrings, and intermediate gearing just adds complexity. Of course, proper maintenance and tensioning is crucial.
Most people who work at computers have problems with their cervical spine. It is likely that this position will cause them nausea or a headache after 30 minutes.
Recumbents are one of the best ways for people with moderate back injuries, ruptured discs, and osteoporosis to keep riding bikes, because they provide extensive lumbar support rather than having shock impact of the rear wheel hitting a bump transmitted right up the spine. A good recumbent seat fairly evenly distributes your weight from your butt to almost your shoulders. They are vastly better for almost every type of back injury, and also reduce wrist/forearm injury for people who have back pain but are trying to ride standard upright bikes by supporting their upper bodies with their arms on the handlebars.
I ride a standard bike because I race, but I wrench for several recumbent riders, all of whom have various back injuries that prevent them riding standard bikes. There are definitely problems with recumbents, but hurting your back is not even in the top 10.
based on a very naive attempt to calculate the psi in a piece of steel tube supporting weight on the end of an arm, i would have guessed 1/16″ wall 1.5″ tube would not be strong enough for that lever arm to the front wheel. that’s why regular bikes are built out of triangles, i thought.
makes me wonder if my naive take is too pessimistic
Thanks for posting my project!
I also have a more simple version of Marauder (no suspension) posted here…
https://chopzone.com/forum/index.php?pages/marauder_lowracer/
Hope to get more DIY bikes on my Youtube chan when I have the time!
Cheers!
Radical Brad – AKA : AtomicZombie / ChopZone
You’re welcome. Thanks for making your video! We’d be happy to hear about your future projects, please feel free to drop us a line any time.
I bought the Atomic Zombie plans for the StreetFox.
I haven’t found a welder that would take on the job of building it.
I don’t know if it’s liability or what, but it’s been a while since I’ve looked
at the plans, at least two years. I’d think something like this wouldn’t take an
experienced welder much time at all. Just my luck I guess….