Recumbent motorcycles are nothing new, but most (all?) efforts are focused on street legal machines. Bob Horn, though, is proof there is at least one (feet) forward thinking builder, who has been working for the past half dozen years to design, build and test a recumbent racer. His persistence and dedication finally paid off when he recently lined up against conventional motorcycles in his first MRA sanctioned road races at High Plains Raceway in Colorado. In fact, these may have been the first ever sanctioned roadraces with a recumbent motorcycle in a grid filled with sport bikes.

Bob the builder

Bob has been a builder for a long time, he built a unique Sportster powered concept back in the early 1990s, and he later built an electric powered recumbent to test some ideas about two wheel steering, but this recumbent racer project has been the focus of his efforts since 2008.

The secret motivator

Whether by design or by accident, Bob did something at the start of his project that may have contributed to its success, he wrote a post on his blog clearly outlining what he was planning to do. It’s all too easy to find an excuse for coming up short if you never publicly commit to anything, but tell everyone up front what you’re going to do and there’s a simple measure of failure and success. Either you did it or you didn’t. Unless you’re comfortable with a lifetime of excuses, you might as well get to work and make it happen.

The Workshop

The project build took place in the palatial surroundings of Bob’s garden shed. We’ve seen some amazing builds come from workshops like this and Bob’s efforts should provide more than a few yet-to-be builders with the confidence to begin. It’s not the space, it’s the builder.

The Kawasaki EXperimental500

While registering the racer at the track, Bob had to come up with a name for the bike, and though there were a lot of nicknames bandied about, the name Kawasaki EXperimental500 was chosen, a take off on the EX500 500cc twin Bob is using for power.

Here’s Bob’s list of answers to the most common questions:

The race number has no deep meaning – it was just an available number.

The exhaust exits out the side, not to the rear – there are no “flaming butt” issues.

The steering axis is not parallel with the front fork – there’s a virtual pivot at the hub.

The EX500 engine is internally stock.

The rear swingarm, vertical link, and drum brake are temporary – a more advanced system will be installed later.

NO street conversion or version is planned. Ever.

NO movie replica bodwork is planned. Ever.

The bodywork could be a lot more aerodynamic, but finished bodywork beats unfinished bodywork every time.

4 (now 6) years construction time in a garden shed at a budget of under $1.00/day.

The donor bike cost $500.00 – the leftovers were sold for $600.00.

Having a full time job not even remotely related to the motorsport industry, younger and older children, internet connection, lack of money, etc… didn’t stop this from getting built.

No, I’m not giving away any design or building advice. Nor am I asking for any.

414 pounds ready to ride except fuel, 50/50 weight distribution with fuel and 150 pound rider. 74 inch wheelbase. Just over 4 inches of trail.

Track time and hard lessons

Early in 2013, Bob had his first track time with the racer. The first session pointed to a few easy to remedy bugs, fixed with a carb kit and a headrest. The second session, though, was more costly as a lowside in a left turn followed by a roll in the dirt meant rebuilding the racer. Thankfully, no injuries, but there were definitely repairs to do which take time and money and a blown transmission in his van used up the race budget for 2013. Of course, that meant extra time to get things ready for the following year.

Real racing

Well, the purpose of a racer is to race and in early May of 2014, Bob lined up on the grid for the first time. He was confident, but realistic. He wanted to finish, learn a lot and not be in last place at the end. He accomplished all three goals, 24th out of 25 entries. He also found he has lots of straight line speed, but his “biodegradable guidance unit” needs some tuning to master the corners, something more practice should take care of very nicely. When you’re riding a recumbent of your own design, there’s a lot of learning to do.

In race two, a few weeks later, he placed 17th out of 18 while shaving six seconds from his lap time, it appears a little practice goes a long way. He’s starting to settle in and identify what needs to be tweaked, on the bike and with his technique. More track time may lead to some interesting battles as the season advances.

Craig Vetter has already offered a Photoshop version of what streamlining might look like on the racer which Bob says has a drag coefficient similar to farm implements, but faster corner technique might be more useful right now and the legality of streamlined bodywork in the racing world could mean it’s a moot point, unless of course, there was a separate class where rules haven’t yet been written.

The beginning of something big?

Bob got a nice surprise when the Discovery Channel called and asked to make some video of his project, you’ll notice a camera mounted in some photos as a result. TV exposure could give Bob and his racer some well deserved notoriety and it could also spark efforts from other builders who, after seeing Bob take the lead, might want to jump in to this form of racing to see what they can do with it, especially if he seems to be having too much fun all by himself. If he’s competitive with conventional motorcycles, it could lead to a whole new recumbent racer series or more mixed racing with both recumbents and conventional bikes, maybe someone with an old Gurney Alligator will dust it off and get on the track, too. Who knows?

Manufacturers may be slow to sponsor this sort of racing because there’s no obvious street version they can sell, though component companies should be willing to get their name out front in what could be a new venue, but it’s tailor made for the DIY home workshop guys. I’m not sure how many hands on builders there are ready to take on a project like this when the end result is for track use only, but we might soon find out and since one of Bob’s aims with this project was to keep costs to a minimum, his success is another plus for the home builder.

Isn’t it refreshing to see something completely different? I love this whole project. He had an idea, designed it, built it and now he’s raced it. It’s taken six years so far, but I have a hunch the years going forward will be a lot more fun. Nice work, Bob! Very nice work.

Link: Rohorn.com

Link: Motorcycle Roadracing Association

