Recumbent Honda 90
 

I've had a couple of requests to start a new thread, so here goes.

First a little history :-

I've been riding motorbikes since the late 60's, everything from mopeds to 1000cc 'superbikes'. It was my ambition to build a streamlined feet first motorcycle after reading an article about Craig Vetter's mileage challenge in the early eighties.

Having no fabrication or welding skills, I decided that a Honda Cub would be an ideal candidate as a 'first attempt', as the frame layout would need very little modification.

I eventually acquired a 1981 c90 in 2002 for the princely sum of £30. This sat in the shed for around 8 years until I finally found the time and motivation to get started.

The dream was to build something like Craig Vetter’s original streamliner.

http://ts4.mm.bing.net/th?id=H.47235...58423&pid=15.1

I set myself a target of 70 mph and 200 mpg (uk) at 55 mph.
70 mph is easy (I’ve achieved a GPS checked 68 mph without the fairing), so I’m guessing 80 mph is possible with a slippery fairing and optimised gearing.

200 mpg is an arbitrary figure which may not be achievable without fuel injection, but it’s important to set your sights high, rather than say ‘that’ll do’.

It started like this :-

http://ecomodder.com/forum/member-ir...-honda-002.jpg


With the front footrests bolted to the fork legs (not recommended!), and a hand operated gear change.

After further development, being loaded on the recovery truck following another seizure:-

http://http://ecomodder.com/forum/me...2-im000957.jpg

I think the 3 piston seizures were probably due to the engine over revving because of the standard gearing and reduced drag.

It was around this time I got involved with the C90 club, a great bunch of hard core Cub riders who travel all over the UK and Europe on camping trips. A top box and panniers (OK plastic boxes!) were fitted in order to carry the camping gear.

http://ecomodder.com/forum/member-ir...5-p3070031.jpg

The battery has now been relocated to its original location,

The original engine was replaced with a 4 speed 125cc motor, which allows a reasonable cruising speed without overstressing the motor. I also fitted a 2 gallon tank to improve the range between fill-ups. The bike is so comfortable that 200 miles without a stop is easy.

Next stage in the evolution :-


http://ecomodder.com/forum/member-ir...5-p3010204.jpg

This is where I am at the moment :-


http://ecomodder.com/forum/member-ir...t-p1090434.jpg


The dustbin fairing (which needs a screen and some remedial work) is held in place temporarily while I work out clearances and fixing brackets.

http://ecomodder.com/forum/member-ir...3-p1090437.jpg

Notice how well the fairing lines up with the panniers, this was not accidental, it may be possible to fill the gap between fairing and panniers at some point in the future.

I want to keep as much fairing surface area as possible to reduce drag, but I will need to get my feet down. I’m thinking of creating spring loaded flaps to achieve this, but I’m wondering whether a turned up fairing edge (to direct the airflow upwards) might be a more elegant solution.

I’ve recently rebuilt the carb with new needle and jets as the motor was running a little rich, but haven’t been able to test the results due to stormy weather. I need calm weather to set a baseline fuel consumption so that I can quantify the effects of fitting the fairing.

The bike has covered several thousand miles over the past 4 or 5 years, and is my favourite form of transport, my Harley, Pacific Coast and Shadow rarely see the light of day.

My best fuel consumption so far is 140mpg over a 300 mile motorway (freeway) run, which was with the throttle wide open and slipstreaming trucks whenever possible. Still aiming for 200 mpg.

I'm happy to share my experiences with anyone contemplating a similar build.

Not bad. Barry Weiss from the television series Storage Wars has a tear drop motorcycle shell around his bike. :eek:

http://i237.photobucket.com/albums/f...012/file-8.jpg

That is Awesome!! I, for one, would like more details, impressions, etc. It looks like it would be a fairly easy to duplicate project.

That Barry Weiss thing is a Blastolene creation. It isn't so much a streamliner project as it is an art project.

That said, it would be pretty cool to know just what its Cd is. It looks pretty good.

Can you explain the setup on your front wheel in the pre-dustbin fairing picture ?
I think it might be your gear shift but I dont understand the layout (foot rests still attached to the front wheel ?)

I'd like to see a more detailed build on that as well. You can see a picture of it in his album.

I've noticed on many cubs there is a "horn like" protrusion where the gas tank is that would make a semi recumbent position difficult. I assume this can be easily removed?

http://www.midamericaauctions.com/wp...cub-1-5316.jpg

Interesting project. I've already considered to make a Honda-based recumbent tadpole tricycle.

http://ecomodder.com/forum/member-ir...81-c90-004.jpg

Footrests attached to front forks did not work well, any small movement would cause the bike to swerve, couldn't adjust my position in the saddle without wobbling all over the place.
This photo shows the current footrest layout, gearchange lever on the left connected with a stainless tube. I should have used a heavier gauge round tubing for the vertical section, the square section tubing flexes a little and had to braced. Left hand operated rear brake.

This 'protrusion' is the fuel tank and on this particular model simply unbolts.

This photo shows the frame modifation needed for a more comfortable seating position.

http://ecomodder.com/forum/member-ir...052011-038.jpg

Have you cosidered a Piaggio MP3 as a basis?, should be an easy conversion.

I don't know if MP3 are available in Brazil ;-)

The issue with the MP3 is it's very heavy to start with (also the CVT is usually not very efficient FE wise)

I should have checked roosters location. Plenty of cheap Cubs in Brazil methinks.
The MP3 is heavy at 208Kg, coincidentally almost exactly the same as Visionary's effort, but I still think it would make a good streamliner for the following reasons :-

1. It has three wheels with a locking device , so complete enclosure would be possible as it can be stopped with 'feet up'.

2. It leans just like a 2 wheeler, so no handling problems.

3. Minimum amount of work would be required (body work only).

4. Registration would not be a problem as the chassis, wheels and brakes would remain unaltered.

I agree that the CVT is not the most effcient drive train, but with different sized pulleys, gearing changes might be possible. My son had a 125cc. CVT scooter, and that would do 100mpg. without any mods, not too shabby?

It is available in Brazil, but too expensive.


Considering some frame mods that would be required in a Honda frame to turn it into a tricycle it wouldn't actually remain so light. But at least I could keep it lower, which would be better for what I'm considering to do.

MP3 does solve the stop stability issue through the price of increased width and issues associated with CVT transmission (moderate tunability, expensive price, efficiency).
I would be reluctant to use one.

Where did you source the dustbin fairing?

I was wondering : did you finally changed the sprocket ?
Because it occurred to me that Honda might be using the same gearbox from 50cc to 125 variant and small wheel to big wheel only playing with the sprocket leaving you with no potential.
Am I right ?

One of my colleages in the c90 club, been sitting in his shed for a number of years. They are available from TGA.CO.UK Ltd.
Huge choice of rear sprockets from 34 - 50 tooth, unfortunately I'm unable to source anything other than a 14 tooth front sprocket, it's a special sprocket designed for the selectable high/low ratio gearbox. This is not a huge problem, as I can cut and weld a larger sprocket on to the carrier, it's not a easy swap so I've avoided doing it until it becomes necessary. Currently running a 36/14 combination, geared for 60 mph at 8000rpm.

My mistake.
I was still thinking about your too high a rpm while cruising and remembered that I saw some horizontal single with a very small rear sprocket.
But now that I think about it, Innova doesn't fall in this category so my hypothesis falls appart.

Enclosing a Piaggio MP3: Already done in Belgium
 

Not really. It would be a very brave man (or woman) who did not leave themselves the option of putting a foot down with an enclosed MP3.
You can see from this photo that my Belgian friend Steve Van den Berghe wisely fitted hinged foot flaps for precisely that reason.
Van den Berghe CabinMP3 | FF Web

However, the drawback with the MP3 is that the two front wheels are precisely where you want to put your feet once you're on the move, for a more laid-back recumbent position!
Peugeot's new rival TTW, the Metropolis 400, has a bit more legroom, but the problem is still there. Peugeot Metropolis 400i review - Telegraph
And the two front wheels are themselves less aerodynamic than one.
PNB

Update on progress
 

The wee beastie is almost finished. I say 'almost' because I don't think it will ever be completely finished, projects like this tend to continually evolve.

http://ecomodder.com/forum/member-ir...t-p3170453.jpg


It's the first time I've used basecoat and clearcoat from a gun, I got some bad advice and consequently ended up with a poor finish. To be honest, the fairing moulding is more than a little uneven, so the job would never be perfect. Just to pove a point, I gave the tank a coat of clearcoat, and going with my gut feeling with regards to gun pressure and paint thickness, the result was almost perfect.

http://ecomodder.com/forum/member-ir...t-p3170454.jpg


Took it out for a run yesterday, probably because of some recent air filter changes I could feel it holding back between 3/4 and full throttle so I think a bigger main jet is needed. Nevertheless I was clocked at 65 on the flat, so with some gearing changes I think my target of 70 is realistic.

Did a 55 mile run along A roads, B roads and dual carriageway and I wasn't 'hanging about', fuel consuption was 166 m.p.g :D result !. General running around before fitting the fairing was between 100 and 120 mpg., so a 40% improvement which I think is in line with general consensus.

I have more testing to do, I'm hoping for 200mpg. at a steady 50 mph cruise along a flat road (not easy to find in Wales).

It's too early to tell whether gusty conditions will effect stability, I've been reading Teri Tx's thread with great interest and will be incorporating a 'storm strip'. I will report results on his thread.

Fantasstic job. Keep us posted on developments and mpg.

That is really good improvement in speed and mpg, and I like that the fairing is prefab (and not TOO expensive) plus simple gearing changes. 45mph to 70mph, 110mpg to 160mpg. I think we are going to see quite a few more "streamliners" after folks realize the low cost and relative ease of this kind of project with those kind of results.

And it looks quite comfortable to ride, laid back and lots of protection from the elements from head to toe (especially if you can keep moving). I've ridden naked bikes year round in the midwest, that looks positively luxurious :)

Thanks for the comments guys, P-hack I hope it will encourage others, I'm happy to share my experiences and offer advice to anyone contemplating a similar build. In the words of Sheepdog44 'I try to be helpful. I'm not an expert'

The total cost including the donor but excluding my time, is around five hundred dollars, most of the cost was replacing or upgrading the worn out engine and cycle parts.

The fairing was 50 bucks secondhand, lexan for the screen $20, my buddy did the welding and fabrication of the footrest hangers and fairing brackets, also modifications to the frame and exhaust for free.
Don't worry I'll take good care of him, I will need his help again.

I bet Honda would be interested in seeing this!
Their engineers probably would spend a million dollars on a test bike to achieve these mileage numbers!

1.7 litres per 100 km ! I'm impressed ! and I really wish I could find a dustbin fairing like that one especially at that price :)

One of your photos shows a cover over the panniers that appears to be a more complete fairing aft, is that the usual now or the exposed panniers ?

http://i983.photobucket.com/albums/a...o/IM000917.jpg


Our rego boys probably wouldn't allow this mod, they hold original frames to be sacred but even without it my bum would only be 4 inches higher, the rest of it should be acceptable .

We don't have that model of step through in Australia but we do have a vast number of CT 110s as the Post Office uses them as the standard mail delivery vehicle.

Does the geometry look sufficiently similar to your model to work as you have done ?

2010 Honda CT110P (ADR)

http://pic40.picturetrail.com/VOL282.../409075310.jpg

Hi PeterS,

It's a Postie bike!, there are guys in the c90 club who would give their eye teeth for one of those. Probably a better starting point than a regular c90, bigger motor, proper forks, and possibly a 4speed gearbox?.

I've done some checking on the c90 board http://http://www.c90club.co.uk/index.php?sid=27297ca41e97386835433700e58a4f67
and it seems that they are a derivative of the 6v models, in which case the frame would be identical to mine. There are 'gurus' on this board who can advise on everything appertaining to c90's, I strongly advise you to join.

The frame cut is not essental, by raising the seat an inch or two it could be avoided. In fact, I used the bike for some time before notching the frame, at the time it was the easier option to modify the frame rather than add more padding to the seat.

Conventional panniers (they are actually, easily available tool boxes) were fitted for convenience, that and the fact that in it's previous form it was rather unkindly called 'The Wheelybin'.

I wish you the best of luck with your build, the best advice I can give you at this moment is to do it in stages, in that way you can roadtest each stage to make sure it works for you in terms of comfort and fit. I spent a lot of time re-doing things because I wasn't happy with the result.

It might be better to PM me you want any specific details.

Regards
Ironside.

Thank you Ironside, it appears that the CT 110 is the basis of many different options and it's certainly a popular little machine over here. I'm sure you've heard about the bloke who rode one from Sydney to the UK !

The Honda C90 Club • C90Club.co.uk

Joined ...as AeroSib

Ironside, I understand that the side openings are for ventilation, but could you make them so they could be manually opened and closed? In the closed position the aero would not be spoiled, and you may not always want the cold air rushing in.

Oh, sorry - I just noticed you're in the UK, so no threat of anything really cold;)

Piwoslaw - your observations regarding the ventilation slots are correct. I have cosidered closing them off, or redirecting the flow toward the cylinder head to aid cooling, or to the base of the screen to improve the airflow over the top of the screen.

At the moment, I have no problem with either of these issues. I think the vents help to equalise the low pressure area behind the fairing as I can feel no significant buffeting, also I will probably be glad of the ventilation when the weather is hot.

I don't want to do anything which might adversley affect the useablility, it's no use having the worlds most streamlined motorcycle if can't be ridden on the street, or overheats after a fast run. There are compromises that have to be made with regards to efficiency against useablility.

Regards
Pete.

Ironside , have you ever used the aero calculator tool at the top of the page to work out your CdA ?
Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com . I'd be very interested in the area and what you think the drag figure would be ? .4 ?

I have to admit that your job thus far is the most achievable I've seen here. That dustbin fairing would be the biggest task but it's something I'm going to have to build no matter how I proceed. A CT 110 is available for about $1000 ... that's fairly cheap for an roadworthy bike of any variety here.

PeterS,

The only reference I could find regarding the Cd of dustbin fairings suggested it would be around .44. Using this figure, together with the known bhp, frontal area, weight and performance, seems to agree quite closely with the calculator.

Don't be afraid to make you own fairing, it's not rocket science. I found a photo of the one that I made but never used. Basic shape made out of chickenwire, then covered with fibreglass, there are plenty of instructions on the web. It wasn't as lumpy as it looks in the photo, the plan was to smooth it out with body filler.

http://i983.photobucket.com/albums/a...photo/c903.jpg

Get yourself a donor and make a start, it doesn't have to be finished in weekend. In the worse case scenario you can put it back to standard and sell it on. Take a look at Craig Vetter's build, Chapter 47 (I think), there's a photo of David Hyatt with his recumbent Honda passport.

Ironside

.44 ? That's quite good for the project so far . Do you think you could improve the rear section further ?

I'm quite sure I can build a fairing , it's just the time involved that is hard to find at the moment. I seem to never get beyond half way down my "to do " list !

As you say a cheap donor bike is the first step.... I'll do that .

Something like this .Honda CT110 Postie Bike Custom Cruiser in Riverton, SA | eBay

Careful that you're not paying for 'tricked out' bits that you won't use. Another solution to the fairing could be based on one of these :-

NEW 2012 Universal 450L Aerodynamic Roof Rack Luggage BOX POD Carrier in Dandenong North, VIC | eBay

Full enclosure on the cheap.

Postie bikes here are usually just base models as sold of by Australia Post with about 30,000 km on them. Quite good condition and going.

I'd like to build a fairing based as closely as I can on Craig Vetter's Zero although your would do me very nicely too!

http://pic40.picturetrail.com/VOL282.../406863689.jpg

Thus far Ironsides little Honda is looking the most practical. His cd is around .44 by his calculation and this without much work yet on the rear section and with open sides.

Frankly that's a very good result and yesterday I was mentally comparing it to Jacob's ultimate Velomobiel and thinking about the rear of Jacob's bodywork and wondering if it was too rounded. A heretical thought of course but as Ironside and Jacob are running superficially similar machines although the Velombiel had fuel injection and is fully enclosed while Ironside's is quite open .

The Vetter body above has a hard rear edge and from my reading this appears to be very important and possibly a fault with the Velomobiel ???

Any comment ?

Ironside . Do you have a finished rear fairing shape in mind ?

Kamm tails
 

Hi Peter,

I too have wondered about Allert's rounded tail. It seems he is loosing the benefits of the Kamm effect as I understand it. I notice his and Theo's (they are business partners) velomobiles have rounded back ends too. Theo may be able to expound on the reasoning if any. My attempts to email Allert at the address Theo gave me failed several times and I gave up.

I think Allert's rounded tail is more for appearances although tastes in styling differ. I wonder more about the swoopy creases on the sides. They COULD be for lateral lift spoiling but as I said, I couldn't ask Allert in my email attempts. If Theo is reading this, he could clear this up.

Terry Hershner's Zero with the Vetter nose has a classic Kamm tail. Obviously he (Terry) is of a different opinion than Craig about long tails. I notice too that Terry's transition from the cockpit back opening is rounded compared to Vetter's sharp edges. I think Terry is on the right track in that regard. Reading the recumbents.com site, some of the HPV folks also have rounded edges on their transition from the open cockpits to the tails.

The Kamm effect works as I have a day sailing catamaran (Nacra 5.2 -- 5.2 m long) with a stern that is cut off like a Kamm back. At speed, the hole in the water can be seen to close up about 10' or so past the edge, effectively making the hulls that much longer. For boats, hull speed is a direct function of waterline length. A boat operates in water of course where skin friction is very important. A catamaran goes fast largely from having a lot power driving it. A brick can be pushed fast too, the Space Shuttle was such an example. Had the glide ratio of one too! :)

-- Teri

Recent images show the Zero with a tail, there are probably advantages but I would be unlikely to attach one if just for ease of parking in motorcycle parking zones.

http://pic40.picturetrail.com/VOL282.../409165308.jpg

Ironside, would you have a photo of yourself on the bike with the fairing fitted ? I'm trying to get a scale ... the Honda 90 is a small bike and I keep comparing it to a larger one in my head .

If you look in this directory on my website

Index of /graphics/MotoGuzzi

you'll find a number of photos of the Guzzi GP dust bin fairings that were developed in Guzzi's wind tunnel.

The fairing use on this Honda is an aftermarket item designed to appeal to the cafe racers of the period (late 50s early 60s) and could probably be improved a fair amount. NACA ducts instead of those air scoops would be a good start. The fairings on the Guzzi flat singles didn't need scoops like that:

http://www.eurospares.com/graphics/M...zi/guzdb1b.jpg

cheers,
Michael

I appreciate that Michael , it's just that Ironsides' Honda is a very small bike (a lot smaller than a Guzzi) and with the lowered seat and ff position it would be interesting to see his riding position.