Leonhardt 410 Cubic Inch V-Twin Motorcycle
April 17th, 2007 by Paul Crowe - "The Kneeslider"
Over a year ago I pointed out a project over in Germany being built by Clemens F. Leonhardt. Clemens had some very big ideas but at the time all you could see were design drawings, and when you consider what this project is supposed to be, it’s easy to dismiss it as a design that will never happen.
Well, checking back I see that progress is being made and as these photos show, it’s big. In fact, until Clemens gets in the picture or another bike is next to it, you can’t imagine how incredibly big this really is. Yow!
Especially in light of the Jesse James and JRL Cycles radial engine bikes, using the relatively small Rotec engine, the Leonhardt bike instead uses two cylinders from an old 9 cylinder radial aero engine, the very large variety, which gives you a 350 horsepower, fuel injected, 6728 cc / 410 cubic inch monster V-Twin. It has a 3 speed transmission with reverse. The motorcycle’s overall length is 134 inches and weight is 870 pounds. Seat height is only 31.5 inches, pretty reasonable and lower than some production bikes out there. Speed will be electronically limited to 155 mph.
Original plans were for tires from a Boeing 767 but he’s now found a supplier by the name of Rigdon willing to make custom tires in the appropriate size which are, you know, BIG!
The rolling chassis is shown here and this is not a one off custom. He plans to make a small number of these for customers and a sidecar version is planned, as well.
I really want to see this one when it finally gets on the road. He’s working on another project, too, building a motorcycle around a Hatz single cylinder diesel engine which looks pretty cool. I like this guy’s work.
Another photo and links below:
Link: Clemens Leonhardt
Related: A Real Monster V-Twin
Related: 5000cc V-Twin by Lucky Keizer
Posted in Engines, Motorcycle Builders, Motorcycle Design
| Top Of Page
30 Responses to “Leonhardt 410 Cubic Inch V-Twin Motorcycle”
Please read before commenting ...
This is a public forum, NO PROFANITY OR PERSONAL ATTACKS WILL BE TOLERATED! STAY ON TOPIC! All comments are filtered, if yours does not appear, do not resubmit, it has been held for review. Comments may be edited or removed by the moderator. Above all, keep the conversation civil! Thanks.
April 17th, 2007 at 11:30 am
870 lbs. ? That’s crazy….not much more than a HD or a Kawi mega-crusier (relatively-speaking).
NBA stars should take note
April 17th, 2007 at 11:35 am
Ummmmmmm.
BIG.
Yep, it’s big.
April 17th, 2007 at 1:23 pm
How will this handle the ‘twisty bits’ compared to the ‘Wide Tire Bikes’….?
April 17th, 2007 at 1:43 pm
Wasn’t long ago I was wanting a bike that a 6′3″ rider would be comfortable on. Presto, here it is.
Wonder what the tab in will be?
April 17th, 2007 at 4:01 pm
What’s the point? it won’t handle i’m not even sure it would be able to turn at speeds more than a crawl. I consider this a waste of engineering talent.
April 17th, 2007 at 4:36 pm
But us Aussies have seen it all before…
http://www2.hunterlink.net.au/~ddped/rrv2.htm
And Lucky raced his…
April 17th, 2007 at 4:54 pm
Think of the gyroscopic forces those wheels & tires will create at high speed! Even with the length leverage from forks to grips (~3′), I am guessing some form of power steering will be needed just to start a lean. Note, it looks like four brake disks up front. Given the weight is no more than some cruisers, and given the size of the contact patch, that is a lot of stopping power.
April 17th, 2007 at 5:38 pm
air cooled boxer twins with funny front ends, autobahns, Nurburgring, and THIS?!?! what do they put in the water in der Deutschland?
April 17th, 2007 at 6:05 pm
I’d love to see this thing on the salt flats at Bonneville.
April 17th, 2007 at 6:34 pm
It’s like the mini-bike concept in reverse, isn’t it?
What’s the sidecar? A Chevy Tahoe?
It’s sad that Andre the Giant never lived to see this motorcycle.
April 17th, 2007 at 10:04 pm
Please place this bike in the same category as underwater scuba-diving weddings with an Elvis impersonator.
April 17th, 2007 at 10:08 pm
“..Original plans were for tires from a Boeing 767..”
“..two cylinders from an old 9 cylinder radial aero engine..”
Hmm, Herr Clemens what about a C-130 with a loong forked front landing gear.. a F-16 with Corbin seat and pulled down handlebars..a Cessna 172 with kickstarter…
Out of jokes Clemens, congrats and keep creating these amazing machines!
April 18th, 2007 at 4:09 am
Wow. I like. If the entire bike was scaled down, so that the engine became the main focal point and it looked slightly large instead of ever-so-slightly small like here, and perhaps if it was more like the Aussie one, then I’d like it more. Still… Rocketship. Rocketship.
April 19th, 2007 at 11:39 am
why does a 6.7 liter engine look puny and underpowed in this application? I’m ok with over-the-top crazyness, but without the rider to give a sense of scale this thing looks like a toy. it needs smaller tyres, or bigger engine…
the line of sight for the rider spooks me, too…do you think he could see the brakelight of a rider if he was following close?
April 20th, 2007 at 12:50 am
I’m thinking that the detractors here may need some fiber in their diet. This thing is a piece of mechanical artwork, NOT a replacement for their crotch rockets. I love it! Keep dreaming BIG, Herr Leonhardt!!!
June 4th, 2007 at 8:19 pm
I met Mr. Leonhardt about one week ago. And I took a seat on the GUNBUS. That is the second one. The first one had an automatic transmission and he went 200 km/h with it. C. F. Leonhardt is a calm straight old school engineer telling me that he never liked usual solutions. I found out I’m not alone in saying that a BossHoss is an ugly bike with its too small tires and no shape. Yes, it is a bigbike. I save my money…
September 13th, 2007 at 3:27 pm
Are those the “Jugs” off of an R-1820? I missed the part on how he plans to start it. One kick-back would throw you over the moon!!!
September 30th, 2007 at 11:46 am
I’m looking at the vehicle trying to find the transmission or method of power delivery to the rear wheel.
Also any type of exhaust
Smart and necessary is the extra disc brakes to tame the gyroscopic forces of those BIG wheels.
Use of an established type of motor is a plus.
Its difficult to picture trying to turn this beast at low speed, easy to see why it comes with a(n) (invisible) reverse gear.
All in all, as an engineering idea, its great!
You can just see Arnold with some 50 cal. in an action flick.
October 6th, 2007 at 2:02 am
orange county who?
October 10th, 2007 at 2:20 am
This bike is too big, maybe only suitable for Shaq O’Neal or Yao Ming…
October 22nd, 2007 at 1:22 am
Yeah…the first thing I thought when I saw those tires was “WTF, did someone park their 747 in a bad part of town?” Actually, 870# ain’t bad considering about 200 of that is rubber.
If I were to do it, I’d orient the crank front-to-back, using either a 90deg. V or horiz. layout. That way, the tank could be dropped and more realistic dimensions could be had. (But then it’d look less “like a Harley”…)
Actually, I had the opposite thought: 8 Harley jugs in a radial as an engine option for experimental a/c pilots who love the “round engine” look. (I’m actually surprised he got 350hp, as I thought those radials redlined at 2500rpm.)
November 12th, 2007 at 4:18 pm
hacking up a beautiful radial engine to make that abortion of a bike….. is nothing short of criminal damage.
November 14th, 2007 at 8:25 pm
This is the same as one that was built by an Austrailian back in the 70’s. That one was closer to real size and het nearly 200 mph. Woobly frame held it to that speed. This one looks basically worthless
November 27th, 2007 at 8:58 am
Ooooooooo Wahhhhhhhhhhhhhhhhhhh
Uber cool and so totally gay!!!!!
Now that is a real mans bike.
It’s absolutely excellent.
The ONLY donwside I can see with it is…. you could get between the cars in bumper to bumper traffic… cause it’s actually narrower than the rider…
But a “turn on a dime” moped it aint….
This is a really really cool looking bike.
It’s funny tho, the really nasty “shit heapers” contributions, are done by people who are too stupid to try and too lazy to follow through…
I’d love to have a ride of this…..
POWER-WaaaaaaaaAAAAAAHHHHHHHHHHHHHHH
January 8th, 2008 at 6:47 pm
Okay I want the off road version YEA.
January 9th, 2008 at 2:32 pm
The guys that would buy a bike like this would in all likelyhood be a lot tougher than those tatooed love boys of the Harley mindset.
February 18th, 2008 at 5:10 pm
Is it done,would like to ride it but i know if that happens i would want to get one. thats means i have to sell my ktm 950 now
February 20th, 2008 at 1:05 am
OK, so I’m a girl–I agree with Bryce (above) would love to see 7.6 liter, 350 HP monster out on the Bonneville Salt Flats–I wonder if you could launch it out to Snowbird ski area?
Gotta love thos German engineers.
February 21st, 2008 at 6:50 pm
Note the Sidney Rigdon inflated ego tires.
Perfect.
(inside joke, sorry)
March 2nd, 2008 at 10:26 am
what an interesting artical to say the least. as a previous motorcycle shop owner and mechanic as well as a current rider, this really is the ultimate bike. it’s always nice to see someone thinking outside the box, that’s how new ideas evolve. larry wimmer