Wow! I like it. I assume it CR500 powered? What hp are you shooting for?

I totally dig your enthusiasm and this kind of project in general.... but, I don't see how you can keep this thing sub 200 lbs. The Japanese factories, with all their wizardry and money, could only keep production RS250Rs and TZ250s to about 220lbs. And that's dry weight. I'm assuming you have a CR500 motor in there, which is really an ancient, heavy motor. Unless their are replacement cases and head available that are significantly lighter? Also, a 500 single 2-T motor is going to be hella buzzy, and won't last long on tracks with very long straights.

Comments?

And, is that a carb I see? Why not FI?

So.. you're totally right about tradition bikes and their processes not being about to get weights that low. I have a bit more help though... my work as an engineer revolves around structures, specifically finite element optimization of both metals (typically high strength aluminum alloys and titanium) and composites (typically carbon fiber).

Every nut, bolt, spacer, etc has been either measured or calculated and mass is tracked in a BOM. I have most of the parts actually physically here too to scale accurately to check against CAD measurements.

This bike uses a pretty standard main twin spar frame construction mainly because I didn't want to spend too much time there, but outside that it is all rather interesting stuff. Every bolt on the bike has been run through a calculation spreadsheet of mine to determine sizing- some fasteners have been replaced with HS6082 or 7075 AL bolts, many are 6AL4V titanium. Axles are 7050T651 AL for the front and 6AL4V for the rear. Their internal profiles being iteratively optimized in simulation for strength and stiffness targets. The rear sets are made from anadvanced Lithium-Aluminum alloy which is several percent less-dense than 6061 but about 9% higher in elastic modulus, so I am able to achieve the foot peg stiffness I want while using less material that seen on average.

Handlebars are carbon fiber. cooling ducting is carbon fiber. The carbon seat support doubles are the radiator support and partially the exit ducting to the radiator, under the seat. It is integral to the monocoque body/tail. In this way, lots of mass is saved by not having to have multiple structures doing different things.

The motor has been worked over to remove any extras. Titanium studs, titanium nuts. The kickstart and kickstart gears (heavy gears!) have been removed and a plastic spacer fitted to where they were, since this bike will only be started by a portable starter.

The cooling system uses thin AL hard line in most places to save weight over rubber hose and is very small- this is a time trials bike, so it is only designed to run a few laps at a time. Enough to hear the tires and brakes to set time.

The rear brake disc is Carbon/SiC. The rear brake caliper bracket is titanium, also another part that was material optimized via an iterative optimization code.

A lot of other things.

These are things that OEM bike makers just can't do due to cost limitations (Titanium and specialty AL alloys do not come cheap) and design time or manufacturing limitations- often times designing parts to be lighter could be done but they lack the time to exercise such detailed simulation work, or they are limited by production lines and tooling costs (tooling up ways to mass produce carbon monocoques is not cheap, let alone to material cost to make each body). I'm hired by companies to solve just these problems- balancing materials development, structures optimization, and mass production tooling and piece prices. Thankfully for this project I am only building currently 1 of these, with a potential for maybe 2 more once the first is completed. I'm not tracking my own costs. I don't really want to think about it.

Anyways. back to the motor. CR500 is an old motor, but it is surprising well designed- it is one of the tightest shrunk-wrapped cases i've seen a a 'big' single. The entire motor stock out of a 1991 CR500 weighs if I recall correctly (without pulling up my mass tracking sheet).. about 29kg. With my rework that is down to about 26kg. It has been bored slightly larger and will run a lot higher compression and with computerized ignition, port timing changes, some exotic fuel... and a lot of other details I expect to push around 80HP from it without getting to crazy. There are some who build them for over 100HP but with bigger bores and more work than I am willing to do at first. Maybe later. My main reason for going with a CR500 motor was... I had one laying around when I started this project and I just thought "hm why not". They are easy to rebuild and parts are cheap and I will be melting a lot of internals. The other engine I was considering using was a Aprilia SXV-550, which weighs about 33kg stock and can put out something like 75HP. I could have probably got that engine to a similar power-to-weight ratio but it would have been more expensive and the exhaust and intake more weight and more challenging.

It won't be all that fast compared to, say, my MV F4. But it will be a lot quicker on the twisties.

196 lbs (88kg) is light but it could be lighter- I am using RS250 Cup aluminum wheels- because I think they are dead sexy and I have had a love for that wheel design for decades- but they aren't super light. A set of carbon wheels made to fit (the wheels are skinnier than superbike wheels- due to the low weight/power, the rear is only a 4.5" wide rim vs. 6" for most big bikes) would cut another 3kg or so - 6.6 lbs.

Also the hugger is to keep the tire from throwing rocks into the radiator core, which is right in front of it unprotected under the seat. Maybe that actually isn't an issue, but I dunno, I have seen how sticky race tires get and even if it doesn't happen on track, when you are riding the bike into the pits I have seen lots of marbles get picked up and thrown by race rubber.

It is actually Carbon/Kevlar and is only 2-3 layers thick, depending on the area. It's not a pound of two... it's about 200 grams

And the vibration from it being such a rowdy single- I have thought about that, I know it will probably make the bike impossible to enjoy. But I had this engine in a CR500 supermoto before and rode it on the street a while and.. I lived with it.

Also, The engine is being built for making power higher in the RPM band and on the supermoto the real bad vibration through the seat and bars was really in the 3000-5000 rpm area. I plan on spending all my time with this bike between 6000-8250. Where the frame excites/damps frequencies on this new frame though... I haven't explored. We'll see....

Schumi, you are my new hero. :D

Found two moto Morini 350's in a storage unit that my employe put away 26 years ago. One ran before storage, one didn't, I'm working on restoring the one with the missing engine. It's a scavenger hunt right now for parts.

http://forums.pelicanparts.com/uploa...1469911619.jpg

Wow! I cannot believe I have never seen/heard of this company before. I love that. I am not much of a Duc guy, but one day I want to build a bike with Ducati air cooled 900.

Did some quick searching, that bike is their 'F042'- based on a 2V 1100 making 95HP. They claim the dry weight is 139 kg! That is light, but yeah.. not super light. Most of that extra is engine... I'm sure that 1100, while a sweet sounding machine, is a good 45kg+. Still nothing beats two strokes in power-to-wight. Lots of weight advantage to not having big heads or camshafts or cam chains. And those air cooled Ducs have to have some pretty heavy cylinder castings and a lot of oil volume to soak up heat.

That said, that is a bike you could ride all day long and then ride home too. An I bet the power delivery is like butter. What a beauty.

OK, you've obviously done your homework :)

I am totally digging the project. The engine is the sticking point for me. Have you considered a modified Aprilia RS250 (Suzuki VJ22) motor? With ignition, heads, race fuel, and a big bore kit, you can go all the way to 100hp. Stock is about 58HP to the rear wheel with pump gas, so I would think 75HP would be readily attainable. I'm thinking the engine weight would be pretty light? I have a couple engines on my bench if you need me to weigh one.

Absolutely awesome project, Mike. Just out of curiosity, which CAD and FEA softwares are you using? I'm a CATIA V5 user myself.

Love Morini's I have a one in my moped. Would like to get one of their super bikes....

While the CR wasn't free it was damn close, and modding it for big power is damn cheap. I may get wild with different fuels. I won't feel bad when I melt the top end every 4 laps. I could never do that with a VJ twin, I am sure parts for them are getting more and more expensive by the day.

I want to do a VJ/RS project in the future for sure, the RS250 bikes were my first exposure to two stroke road racers in person and were an inspiration for this project. One of the main benefits to the monocoque tank/tail structure is technically I could re-use the entire upper body section on other bike frames, and so one day doing this on an RS250 frame and swingarm is a goal. If you could get me what a VJ22 motor weighs, with noting whatever accessories or fluids it contains, I'd really like that info. I'm moving to France at the end of this year and setting up a small shop, and plan on getting my hands on a side project bike to work in addition while this RC500 project continues.

The RGV's can weigh about 125kg I believe, less on a diet... and that is 1990's materials and technology. Would love to ride one. Love the sound.


Higgins- I use CATIA for CAD. For analysis work, I primarily use various solvers of the Altair Hyperworks suite.

Actually I remembered what I told myself I was going to acquire next already.... it's along the lines of:

http://motorivista.com/wp-content/up...otorcycle-.jpg

SEX.

I'll try to get it weighed this week. Are you a French national? Why moving to France? What area? I ask because Mrs. Motion and I will be snooping around Provence this fall for a place.