2012 Vetter Challenger Build ( 1981 Yamaha SR185 streamliner)

[bschloop]

Hey all,
I am starting my vetter challenger project for the challenge in Ohio in July, and will be documenting the build here. I went to last year's challenge with my stock '81 Yamaha sr185, but the 600 mi ride down in 100+degree heat caused some problems with tire wear and overheating. I blew my rear tire halfway through the challenge, and had to get trailered back to the starting point. Anyway, here is what I have planned so far.

The Bike: '81 sr185- because I already have it
Full fairing with tail, I am going for 24" overall width, and 8' overall length. it will likely be somewhat boxy looking, as I am trying to go for as few compound curves as possible. i read somewhere (can't remember where) that even a brick with rounded edges has better aero than a motorcycle
this plus taller gearing should put me in the 100mpg range, since it can get 100mpg at lower speed (50ish mph).
the biggest obstacle will probably be cooling the engine since it's an air cooled bike, I plan to find a 12" radiator fan and place it in front of the engine with ducting to make the airflow pass over the cooling fins and vent out the back of the fairing, I also wrapped the exhaust header with fiberglass insulating tape made for sport/race cars which should move more of the exhaust heat away from the engine.

Wish me luck,

P.S. Hopefully I'll be taking some pics today to post later

[redyaris]

bschloop
The Yamaha 185, sounds like a winner, If you are going to have a fan give some thought to putting it behind the motor, rather than in front. I suspect though that if you get the ducting right you will not need a fan. You should also have some ducting behind the motor to insure good air flow away from the motor. If done well you may only need a very small fan as insurance when standing still.

[greenjoe]

Sounds cool, best I remember the SR was a pretty simple/straight foward bike... can't wait to sse what you do with the body work. Are you going for the four bags of vittles storage? Good luck, keep us posted.

[low&slow]

Welcome bschloop! Craig Vetter mentioned you and was wondering what happened to you. It's good to see you'll be back competing at the Ohio Vetter Challenge. I'll be competing in Carmel and Washington. Hopefully I can make it out to Ohio also. Definitely post some pictures of your bike. Streamlining an air-cooled bike can be challenged, I hope it works out for you.

[bschloop]

here are a few pics of the bike, I removed all of the body work, which consists almost entirely of a front fender, rear fender, and headlight bracket. I also removed the seat, and placed a crudely cut plywood seat pan in it's place. I'll cut a nicer one and cover/pad it later. I also cut a piece of angle steel and bolted it to the triple tree to move the handlebars forward and down. I have decided to go with a sportier riding position,and i ordered a set of "drag bars" that will make excellent low bars. I've found a couple of cardboard boxes to approximate the size and location of the "vittles" as this is a requirement for the challenge. Last year I used plastic storage totes, and had my camping gear stored in them for the ride down and back.

[bschloop]

oops, helps if I get rid of all the extra white background in the pics. here they are again.

[bschloop]

here's a model I did in google sketchup of what I want the fairing to look like, and another pic of the bike this time with cardboard panniers, and trunk for approximation of size and location. the trunk is longer than it needs to be, but it looks like I'll be closer to 9' long.

If you are going to have a fan give some thought to putting it behind the motor,

I would probably have to move the battery or airbox to put anything behind the motor, as they block most of the space behind the motor.
I have also thought about oil cooling. The question is would that be enough. I used an IR thermometer, and the head gets to about 250 deg F before the crankcase hits 90.

[beatr911]

bschloop, the 185 should produce about 14hp and be just about right, with aero improvements.

I am really interested in the result of not using compound curves. I think this is a key problem to overcome in making an inexpensive shell. As you know Craig ended up with a fiberglass nose to overcome this, but there may be other solutions.

Have you decided on what materials to use? I keep imagining using a frame made of fiberglass tent poles or pvc and using a cotton bed sheet to cover the assembly and doping it all up, like a kyak or old airplane. It's an archaic method but may lend itsself to easy diy.

Anyway, good luck and keep us up to date with pictures. Congratulations on actually doing what I would like to do.

[redyaris]

I think you could offset the small fan to one side and then a add the ducting to get the flow you want when at rest. If you look at most radiators on dirt bikes they are off to the side. the fan it self can be oriented any way you like as long as the air exits the ducting paralell to the airstream.

[bschloop]

Have you decided on what materials to use?

I was hoping to find some chloroplast for all the simple curves, because it's very lightweight and rigid I will need to make a Fiberglass nose cone, but I am going with a much smaller one than Craig. I found some solar/uv curing resin that I am going to try for this. it's supposed to make the whole fiberglass thing much easier, as you have infinite working time in the shade, then you just set it in the sun and it cures. if this resin works I could make nosecones for as little as $50 each.
Does anyone know how much cooling airflow i'll need? I can get small fans meant for venting the engine compartment in a boat, but I don't know if they are big enough.