Motorcycle aerodynamics, a slippery and windy, slope?

[redyaris]

Originally Posted by PeterS

Thank you , an excellent resource !David MacKay FRS: Sustainable Energy - without the hot air: Contents

Gray is an interesting project ,how do you find it in cross winds with the extra bodywork on the rear ? I can see something similar being very useful on the Dreamliner modification .

Any difficulties getting on and off ?

Cross winds are no problem although the bike leans a bit more. getting on and off is not a problem although it is different because I have to lead with the foot rather than the knee. I do recomend that the top of the cargo box taper from the top as fast as posible in order to lower the center of pressure as much as posible. I live in an area that has lots of wind and some very strong wind. When riding north south I get side winds all the time.

[PeterS]

Originally Posted by redyaris

Cross winds are no problem although the bike leans a bit more. getting on and off is not a problem although it is different because I have to lead with the foot rather than the knee. I do recomend that the top of the cargo box taper from the top as fast as posible in order to lower the center of pressure as much as posible. I live in an area that has lots of wind and some very strong wind. When riding north south I get side winds all the time.

Thanks for the reply ,can I assume that the area on the rear turns you up into the wind in a side gust ? Is this comfortable ?Too quick or is it predictable ?

[redyaris]

[QUOTE=PeterS;257244]Thanks for the reply ,can I assume that the area on the rear turns you up into the wind in a side gust ? Is this comfortable ?Too quick or is it predictable ?[/QUOTE
The cross wind does not turn the bike, what happens is that the bike starts to roll in the direction of the wind [force] what happens at the same is the "counter steering" of the front wheel which causes the bike to roll in the opposite direction, resulting in the bike leaning into the wind as it goes down the road. The bike is comfortable. I have only had one incident that caused some anxiety, but the fact that it resulted in no great change in trajectory gave me confidence that only a hurricane would be strong enough to cause a dangerous change in trajectory. The bike almost corrects itself, I suspect that most problems that new riders have is panic as the bike rolls.

[PeterS]

Thank you ,that's quite reassuring as cross wind handling is my only real concern .

Bearing that in mind how do you think my proposal would work in a cross wind ...compared to yours ?

I've made some modifications to this drawing since posting previously , mainly more area at the top rear .

[PeterS]

[redyaris]

The wind screen is to close to the riders head for safety given the rider standard position. The rear section should taper/curve down from the riders sholders toward the rear. Later on you can add a section behind the rider helmet that tapers/curves in/down.

[PeterS]

OK on the taper mods , the rear facing section of the screen would be a padded vertical surface about 4'' wide ...... but ,yeah ,I'll space that out a bit .

[Frank Lee]

You don't want to be looking through a pillar that thick do you? I'd orient the trailing edge vertically and make it thin so if you smash your head into it, the windshield yields not your face.

[PeterS]

A good idea but as drawn I'll be looking over the top .The screen is aesthetics really and giving a bit of light to the instrument cluster .Shards of broken acrylic would be like daggers so it does need thought .

[Frank Lee]

Use polycarb. Or nothing, if it's not needed. That would really simplify the build.