Project 100 (custom enclosed Honda C90 targets 100 mph vmax and 100 km/L FE)

[Frank Lee]

Ohhhhh. Pretty wide tires for a 50 to try to turn then.

[PeterS]

Originally Posted by Frank Lee

Ohhhhh. Pretty wide tires for a 50 to try to turn then.

Agreed, what coefficient of rolling resistance did you plug in to your calculation ?

[visionary]

Tyre sizes are 110/80 front and 160/60 rear. I made an error on the drawing for frontal area. The calculation requires the rear tyre width for the outline, and I extended that for the front tyre shape - making it look much wider, sorry. i will post an amended front visual soon.
Frank - you sold me short by a full 35cc! The C90 is 85cc (presently) and I'm not worried about oversize tyres, its only acceleration that will suffer "significantly".

[visionary]

So the latest image is the frame construction to house the rear body section and storage area. I didn’t make as much progress as expected this week, but that’s partly due to some revision work on other parts of the build. Packaging the rear spring damper unit has required some “repositioning” of the frame bars.
I’ve made the front and rear frame sections detachable from the lower “chassis” section. This will make alterations a lot simpler when I work on the bodywork. Initially I will use the C90 rear light and indicators, but I really wanted to do an integral design with car lamps similar to Allert’s bike. Unfortunately there will be so few C90 parts on the finished bike that I feel obliged to keep as many as possible in order to convince authority figures that “it really is a Honda, honest”.





Below is another comparison image, this time with Allert’s bike. When producing this image I was surprised at how low he was able to sit without a custom frame design. This gives me hope that I might pass the 200mpg mark also.

[cvetter]

Morning again: I see two problems with the Honda 90 powerplant:

To sit up as your sketch shows, you will need something like 15 hp to go 70 with any kind of normal winds and/or hills. I guess you could hot rod your 90 to get 15 hp but then consider the following:

Our experience in the States in Vetter Challenges is that the air cooled motors 180-230cc have the power but they are working so hard and get so hot that they need to have water sprayed on their hot spots just so they don't seize in the Challenge. You gotta carry a lot of water for a 100 miles trip.
Unless you plan to stick the engine out front, Morgan 3 wheeler style, streamliners need to be liquid cooled. If you can get the new Honda CBR 125 you would have a much better chance, I think of reaching your goals. If Honda sold the CBR 125 in the US, I would get one and streamline it.

[jkv357]

As far as high-output 125s go, Aprilia will begin selling this FI 125 4-stroke in the U.S. later this year -



Aluminum frame though - I'd be a shame to chop or cover it up! Interesting to see how it compares to the new CBR250R single as far as performance and FE.

It might do well as one of the "crouch down and get real small" entries from the older Challenges, but would take a lot to get it modded into an upright (scooter) position with the required storage. You'd pretty much just need to use the engine and build you own frame for the most part I guess.

Neat bike as it sits IMO.

[cvetter]

The Aprilia 125 looks very promising and it may be possible to leave it as a motorcycle, too. Take a look at how the first Vetter Streamliner Kit is fitting on a Kawasaki 250 Ninja:

We will be doing a test run between Las Vegas and Barstow November 20, 2011. Anybody want to ride with us?

Craig

[visionary]

Replies
Craig – thanks for the insight! I value your input, and obviously experience counts for a lot, but I knew this was a difficult challenge right from the start. My goal of 100mph is the same as your “70mph into 30mph headwinds”, or as near as makes no difference. The drag calcs (posted earlier) confirm that 100mph can be achieved with 11.5hp. The Honda C90 is 85cc and 7.5hp std, and with mild tuning (inc switch to programmable ECU and fuel injection) should reach this target power. I’ve planned for heat issues, and will use a fully ducted and fan-assisted airflow system. I would prefer to use a liquid cooled motor but there is nothing (that I am aware of) with a horizontal cylinder layout, which is an essential part of the low seat-height design. EDIT - looks like I've answered my own question in the reply below, Doh!
Jkv357 – that Aprilia does look good! My budget for this project would be overstretched to get something like that, and then I could never bring myself to cut it up! The C90 was the ideal start point just because I wouldn’t hesitate to cut it into pieces! Oh, and it’s a horizontal cylinder style. Allert’s bike (125cc, liquid cooled & fuel injected) would have been even better but they are still to valuable to “wreck”. But with a bit of luck I could fit that engine at a later date.

[Frank Lee]

Anything under 180cc would have restricted access to roads in CA.

[cvetter]

Interesting that you bring that up. I wonder why they even wrote such a piece of legislation in the first place. After all, there are minimum speeds posted. There are maximum speeds posted. If you stay within the limits, why would anybody care how big your engine is, anyway?