Lots of assembly required.....

Wasn't me, twas that flying rock. and gravity. and that other rock lying in ambush in the stream. really.

It was before the racing years of Team Incomplete that I started what would be a long road to the design and construction of a complete motorcycle. As a child my dream was to win the Indy 500 in a car of my own construction. Well, the costs of Indy 500 racing has moved up a bit since my childhood so I had to look for a more accessible vehicle to chase my dream in. Motorcycles were a shoo-in. The process was incremental, starting with a 1980 KZ1000 I had that had a losing argument with the side of a NYC taxicab. I flew off and luckily landed in a big pile of garbage waiting for pickup. You’ll rarely hear someone be glad they landed in a pile of trash but it saved my ass! I retrofitted the bike with modern forks, a monoshock swingarm and other bits and pieces and it was an improvement but not to the extent I had hoped. To answer one poster’s question, this was the first inkling I had that the more of someone else’s parts you use in a design the more compromises have to be made, usually to the detriment of overall performance. From here I had a minor role in helping sakurama in the building of the TI Boxer. His results were much better than my KZ was so I got jealous and decided to go whole hog- new frame and ditch the forks. I proceeded to start educating myself on what a motorcycle actually does when it goes around a turn and why. A crucial step in this process was finding a copy of Tony Foale’s original book: Motorcycle Handling and Chassis design: Theory and Practice. The book has subsequently been updated 2 times and I have the honor of having one of my FFE (funny front end) bikes included in it. For anyone that wants to understand more of what is going on with those 2 wheels underneath us Tony’s books are a great resource. They are not too technical and can be largely understood by the layman. I’ve met Tony several times and he is always willing to shed some light on any topic motorcycle related on the MC-Chassis-Design mailing list hosted by Michael Moore (not that one) at www.eurospares.com.

Anyway, my engineering education and Tony’s writings convinced me that a possibility existed to design an improved front end than telescopic forks. From an engineering perspective they are horrible: long lever arm loaded in bending, dual sliding elements subject to large braking forces, and geometrically intertwined relationship among all of the chassis parameters. What the last means is that rake, trail, wheelbase, dive, etc., are all tied together and difficult to adjust independently. It is not too bad for a street rider who is rarely at the limit of performance, but is tough on a racer trying to drop lap times. The design does have some benefits: easy to package, easy to add a steering mechanism, close connection from road to rider’s hands for good feel, and perhaps most importantly about 50 years of continuous development by major manufacturing companies to minimize their drawbacks.

Gotta run for now but the next post will go over my first chassis and suspension designs….

this is gona be good

Pass some of that over here.

Yes please!

I be stuffed! A man after my own heart, on the other side of the world, who (it would appear.....) also sits up 1/2 the night and dreams up ways of making things better than they should be!!!

With the exception of course, that he also possesses the knowledge, skills and resources to do more than dream, I'm in too!

Oh yeah, one question please.
What would be the lightest front end set-up with limited travel (under 2"), that has adjustable rake/trail that you are aware of please? I would love to build a front end for a dragbike other than spindly forks designed for something much lighter and far slower.
One day. *sigh*

This looks very interesting.
For those of us looking to "catch up" there is plenty of material here...
http://moto2-usa.blogspot.com/

I'm in!
Looking good so far!

Modnrod,

Sometimes not only half the night!

A leading link front end can be made very light with a little triangulation of the components and no rework to the bike's headstock or frame. You could adjust trail with an eccentric axle mount or machined inserts. If you spend a bit of time browsing http://www.eurospares.com/other.htm you'll come across a lot of leading link designs. It would give a lot better torsional strength than telescopic forks which could help make steering more accurate, at least when the front tire is on the ground. Is adjustable trail a needed feature? A leading link design would be a lot more work than bolting on a set of different forks. Have you looked at the forks from a 125cc bike? These Aprilia ones look relatively stiff.

http://www.ebay.com/itm/Aprilia-RS125-91-97-Forks-10784-/280621340471

Let us know what you end up doing.

Hey there papaduc - I see we're now neighbors! I just moved from NYC a few weeks ago and am living just up the road in Tigard.

Anyway, as some of you have followed my bikes over the years as I've built and improved them it has always been Chris that is my resource and a fabrication mentor. I have huge respect for the guy as he can literally build anything he puts his mind to. He's even designed stuff for NASA that went up in the space shuttle and he's taught me all I know about machining and welding.

Since Chris isn't adding too many photos yet I'll dive into my archives to find a few. First off here's Chris in his element working on the Hardinge:



While he has a couple of CNC's he uses for most of his building he can still kick it old school on the manual machines.

And, unlike a lot of builders, Chris knew it was important to actually put his own ass on the line to develop his bike and he was a very fast rider:



I'm pretty sure that above bike is the Rotacular V1. We named it because it used a Rotax engine and was pretty spectacular.

Here's the V2 bike. At about this point Chris reached his personal limit on the track long before the bike had and so Todd took over as pilot. I got a few rides on it back then and it was a demon on the brakes - far better than the TZ250 I was racing.





And here's Todd at speed:



The bike's chassis was stunning and stable. Chris will chime in with more detail but the V1 bike was a Rotax air cooled. Chris wanted more power so he adapted a Ducati superbike head and cyclinder to the Rotax case for the V2 bike. He also made his own design slipper clutch. Just take some time to look at the photos above and check out the details - there was very little that wasn't hand fabricated. The bike was pushing about 78rwhp and when it stayed together it killed the competition - not just won but walked away. Even racing against unlimited Buells with double the horsepower the bike killed. The trouble was it suffered a from mechanicals due to the overstressing of stock parts so Chris decided to build his own engine - you know, like anyone of us would.

I've been seeing this bike come together for a while now and Chris has had a blog but I sort of think that this forum is a better place with people from all over the world that will appreciate what he's doing so I'm glad he's here and bringing the project to the inmates. And, as Chris mentioned, I've been after him from the very beginning to develop an Adv bike around this engine and chassis. Once the bike has spent some time on the track and we get a second or third chassis I will be putting some effort into helping with that development. Imagine a bike the size and wieght of a 690 KTM but with the power of a 990? Who wouldn't want that?

Alright, let's see some more Chris!

Bitchin'

The blog was mentioned in here a year or so back and I've been following it with much interest since then.

Good to see it on here where more people will be able to enjoy it, so thanks for taking the time to post for our entertainment pleasure.

Thanks for those shots Gregor, you always manage to show your subjects in the best light. Those shots were all of the MK2 bike, a few years into the project. The first design was christened the 'MK1'. I'm sort of embarrassed to post these photos after seeing yours, but here goes. To lessen the shock I'll start with one of yours. This was visually my favorite version of the bike, TEAM INCOMPLETE in your face!!!!! Yes, were a the amateurs with a 3 color PPG high gloss paint jobs with 3' decal on 6 racebikes. But boy was it fun.....








then sneak in a shot of mine without bodywork.



The MK1 was trellis-like and a lot bigger overall, mostly being down to me being shy about how crowded I should make things.

I was in extreme mode with this first bike, nearly zero degree rake angle, inside out front brake, etc. The bike worked really well but just felt a bit too big overall. It was a good testbed for evaluating front control arm bearings and the latest Moto2 bike's design is a partial throwback to this bike. The inside out front brake looked cool but in the long run it is hard to beat the feel and progressiveness of a good set of Brembos.

This bike had a charmed existance, starting with the obligitory all night drive through to Daytona for it's maiden voyage (boy that was dumb) with the attendant all-nighter at the local hotel and finish welding in the school bus machine shop that used to be a fixture at Daytona. After all that never failed or threw its rider off. Without a reason at least.



In the end I got to finish one of my races and was not last.



In retrospect it was a complete success. Oh, and never test a new bike at Daytona.

You may ask why did I use a popular dirttrack engine to build a roadrace bike around? Many did and the answer is simple, in the US if you want to race a bike with a custom chassis and suspension it has to be either an open class bike (not quite yet, thank you) or a single cylinder, which due to their limited power production are allowed unlimited modifications. OK, maybe I did get a bit carried away with the 'unlimited modifications' part. This bike started before the new 4 stroke MX bikes were around so the Rotax 640 was regarded as a good reliable engine. The lower power output also made me focus on the whole point of the journey: to test an alternate suspension design.

I ran this bike, doing revisions to front and rear end geometry, for 2-3 years in addition to a Honda RS125 GP bike. After learning all that could be from this first go, I decided a complete redesign was in order. I had two main goals- mass centralization and size reduction. Both were achieved.

Although the MK2 bike looks completely different, the chassis parameters are is very similar to the original MK1. Instead of making a trellis because it was cool and Ducati did it, I tried to make the most efficient use of material as possible. I put tubes where the loads were being transmitted between the pivot points and not much else. Since those pivot locations were the output of a set of mathematical equations, the result was very simple and not really up for debate:



and the completed bike was noticeably more compact and centralized.



The bike was immediately faster and in every way a more refined package. The first bike was good but this one really started to show a high level of detail and finish. I rode it for a year or so and when I couldn't go any faster and couldn't make any parts to help, recruiting a faster rider became a priority.

Todd Puckett fit the bill perfectly. A MX racer as a child he was fast, smooth, and possessed with a great sense of feel. His feedback improved the bike setup immensely but that will have to wait for another post maybe tomorrow.

Those are sexy!

Did the exhaust pointing at the rear tire cause any issues with the tire overheating?

Exhaust outlet was never a problem with the tire. I think that by the time the exhaust gas is at the outlet it isn't more than 200 degrees or so and not too concentrated. That underseat exhaust was one of the issues with the overall bike design I needed to correct but not because of tire heating. It was a light bike but just positioned too high. You can see the how the MK2 is noticeably lower and it feels much more flickable as a result.

somehow, WOW! just dosen't cut it.
inspirational!:eek1
i am in the process of getting a degree in engineering, so i can do things my way.
thank you for sharing and inspiring.

noam

Very cool! Maybe it's an engineer thing, but I love the "from scratch" approach - it's a dream of mine to do the same. In the meantime I'll live vicariously through Chris...

I agree. With the opening posts and none of this background it kinda seemed like a just out of school/I got a hold of a copy of SolidWorks kind of hack job but with all this background I am highly impressed!

A question about the original modeling that was shown on the first post: Why are the relief cuts on the fork on the outside? Would it be advantageous aerodynamically to move them against the spinning wheel and leave the outside edge clean?

For now they look nice on the outside! The fairing is not yet done and they may be covered but why would the spinning wheel want to see the high drag area? For now I'm not worrying so much about aero as getting a sweet looking bike. We can worry about aero once we're at the track with a sorted chassis.