Aerotrunk project

[Grant-53]

Yes, I hear that a lot. Been there and done that also. I have spent the last 40 years studying crash testing. A rigid shell with no crush doesn't help much. Look at how your helmet is designed. If the bike chassis is designed to protect you instead of the other way around we have something worthwhile especially if it doesn't feel like a cage. My first car was a '65 Corvair so I'm used bucking the trend. Always do your homework.

[Grant-53]

I stand corrected on one point thanks to aerohead and the chart in the Fairing and Drag thread post #22. Rather than making a tailbox with 5:1 form and 50% Kamm length I have gone with a complete 3:1 form for my bike project.

For those who have questions about high speed slides in a full fairing shell, check Youtube for the videos on crashing race HPVs. The Olin HPV crash took place at Grove City, PA where I did most of my undergraduate work in Mechanical Engineering. When selecting material for the main bulkhead behind the rider, keep in mind the federal regulations for static roof strength is 3 times the vehicle weight.

[low&slow]

I still need to do the A-B-A testing to define the exact benefit of riding with the aerotrunk but in the interum I'll be comparing the difference between with aerotrunk and not. Today I refilled after traveling 106.9 miles, using .957 gallons for a result of 111.7 mpg. This is the best tankfill so far with this moto's current configuration ( 15/37 gearing, enclosed front fender, aero windscreen and the aerotrunk ). I'm done with modifications for a while so I'll just ride with aerotrunk off and see what the difference is.

[beatr911]

Vic, those are some great numbers. Could you go over the full extent of the modifications you've done on this bike? (Pictures also please) That way we can know what to do to get close to your figures.

Trunks are incredibly useful as you know. Unfortunately the blobs and boxes that the aftermarket makes offer limited utility while also trying to make them fit the style of the bike. What have you hauled in your box?

Thanks for the research on this topic. Please continue to update us!

[low&slow]

Hi Garth, Thanks! The 2005 Ninja EX250 has the following modificatons: taller gearing ( 15/37 from stock 14/45), fully enclosed fender, aero windscreen ( from my Yamaha Vision ) and the aerotrunk. Here is a recent picture that shows all except the current , longer windscreen.

The aerotrunk can hold 4 full paper sacks of groceries. I've used the aerotrunk on overnight trips and during the Holidays I brought home a boxed coffee maker that my wife wanted as a XMas gift.

[JeffM]

Looking nice Vic. How is the stability with the aero trunk vs. the boat tail and the enclosed front wheel?

Are you planning on attending the Vetter Challenge in Utah this year?

[low&slow]

Hi Jeff, I would say that the aerotrunk-mounted Ninjette is a bit more wind sensitive than my streamliner. It's not bad and I have ridden it in some pretty windy conditions without a problem. Compared to my first streamlining efforts with my old Yamaha Vision, it is a quantum leap forward.

[low&slow]

I did a ride today with a buddy into the Delta ( aerotrunk removed) and topped off after getting back: 113.7 miles/1.549 gal.= 73.4 mpg . There were a lot of hills and the pace was somewhat spirited but it does seem to show a marked difference without the aerotrunk. I may run another short tank to see what it does during more normal conditions. I think my worst tankfill with the aerotrunk on was around 85 mpg so compared with this one ( 73 mpg) it shows a difference of about 16%. More testing to follow.

[JeffM]

Ok Vic, you now have me thinking of building my own aero-trunk to experiment with. Just what I need, another project (while I'm building the boat-tail how much more work could the trunk be?)

Jeff

[low&slow]

Great! The aerotrunk is super easy compared to mounting a tail. Oh and yes, I plan on attending the Vetter Challenge in Wendover. It'll be great to see you and your streamliner!