Maxwell Cycles from Petaluma (in Northern California) presented a beautiful ebike at the 2017 NAHBS, and it is an interesting example of using a hubmotor as a non-hub. As soon as I saw it, I knew I wanted to write about it.
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Maxwell Cycles
The Maxwell Cycles shop is a small operation, but it has a record for being able to tackle complex jobs, and producing a professional-looking custom product, that is built to a customers spec.
Concerning the style of the ebike that they built for the 2017 NAHBS (North American Handmade Bicycle Show ) Kevin Maxwell Ostrom stated “I’m a motorcycle guy, so I built something a little bit different.” The Maxwell XO1 is a tribute to board-track racing motorcycles, and it has a 100V X 30A = 3,000-watt power system with regenerative braking. Oddly, Ostrom says most of the recent bicycles he’s created have been hung as installation art…
Kevin is a machinist by trade, but…whenever he found himself with his shop between jobs, he used that time to pursue his passion, custom bicycle frames. In 2007, Kevin decided to take the frame-building course at the United Bicycle Institute (UBI) in Oregon, which would jump-start his knowledge base about the techniques that are used to properly build a quality custom frame, and also…what equipment to buy for his shop.
Here is a development prototype he built on commission for the Rans company, many years ago.
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The Maxwell XO1
Kevin has worked on many different projects to “pay the rent”, but…his passion has always been the boardtrack motorcycle racers from the pre WW-One period. He specifically has a soft spot in his heart for the Excelsior brand, and also the very advanced Henderson examples.
Every project starts with an idea, and here is the initial CAD drawing that Kevin made to sort out the size and dimensions of his vision for the boardtracker he had always wanted to build.
Laying out the frame and tank
I suppose you could “buy” a tube notcher for fish-mouthing, so you can build custom frames, but…when you own a machine shop, you can just make a notching-jig from scratch. You will also need a chop-saw, and a tube-bender…and then comes the hard part…
After notching tube-ends to make a snug fit at the joint, you can see the beautiful TIG-weld here, which will be covered with a fillet braze to smooth it over.
Welding-on cylindrical shims to fatten the handlebars at the clamping points.
Kevin hoped he would have enough demand to make several of these, so here…he has made a wooden die to stamp-out the compound-curved fork braces.
Dry-fitting and touching-up the oval holes that present a round hole to the fork-arms after the braces are bent
Looking at this pic convinces me that I would be very comfortable in this shop. If you can think it up, Kevin can make it from scratch.
Assembling the fork parts into a precision jig to hold everything in alignment, while it is welded.
The bluish discoloration at some of the joints show that this fork is about halfway done with the welding operation. The dual forward tubes that are added to the fork for a reinforcement are called trusses.
Its only when you get up close to the finished product, that you see the beauty in the smoothness of every welded joint.
Kevin had not finished the electrical power system for the first prototype by the time of the 2016 NAHBS, but he still felt it would be beneficial to attend, so he could start getting his shops name out there. At the end of the show, one of the attendees offered him enough money that he simply couldn’t refuse, and he sold his orange prototype.
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The XO1 Electrical System
Kevin had some time to do some more fitting work on the electrical system of the XO1, before he had to deliver it to the customer who bought it. My first question when I emailed Kevin was where and how he mounted a freewheel, but he replied that he wanted to have regenerative-braking (regen), so it has a direct chain connection between the motor-sprocket and the large rear wheel sprocket.
The 2016 NAHBS XO1, just after the show (note the motor-mount had not yet been powder-coated orange)
The second frame, which he made for the 2017 NAHBS. Here, it has just returned from powder-coating, which is tougher than paint.
Here is Kevin, standing behind the 2017 NAHBS XO1
Kevin is very happy with the performance, but his only design regret is…now that he has the 3,000W power system running, he plans on upgrading the front brake to a larger 203mm disc with a hydraulic caliper. In order to speed the development process, the show version had an off-the-shelf 160mm-disc cable-operated braking system (front and rear), but the regen-braking helped by playing a significant role in slowing down the ebike.
The motor shown is a Crystalyte 3540, and the current controller is from Ed Lyen. It is an 18-FET size, capable of running an 24S battery pack. The battery is a 104V nominal Lithium-Ion 18650-cell pack from HPC.
He plans to have a street-legal 28-MPH system available for California customers to order, using a 52V X 30A = 1,600W power system.
Here is his Facebook page, and also…here is the Maxwell Cycles blog
We previously have written about ebikes that were featured at the NAHBS, here is our article on the 2014 Paul Daniels mid-drive, and also…here is our article on the 2015 Paul Brodie ebike.
The Maxwell Cycles shop is at
1000 Clegg Ct, Suite BO
Petaluma, CA 94952
(707) 696-4661
Here is a video interview of Kevin with the XO1 at the 2017 NAHBS, courtesy of the youtube channel “Handbuilt Bicycle Guide”
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Written by Ron/spinningmagnets, April 2017
