DIY Rubber Front Wheel Skirts

[MetroMPG]

"What's the go with the car, mate?" Haven't heard that phrasing before.

Should have told him you're building a submarine.

[bestmapman]

Originally Posted by MetroMPG

"What's the go with the car, mate?" Haven't heard that phrasing before.

Should have told him you're building a submarine.

Should have said, "It is radar reflecting material. The cops radar guns bounce off it."

[SVOboy]

Originally Posted by newtonsfirstlaw

Update: Just did some more coast down testing and a couple hours worth of driving.

I guess I'll cut to the chase - using an average of all my figures, taking into account that I was going into a 13kph headwind (as measured by the bureau of meteorology), I get a drag coefficient of 0.19. (I was on the way home). I will probably need to do more testing, but I'll probably be conservative and say that it should at most have a drag coefficient of 0.24.

Regardless, that is definitely an improvement. The lower road noise is noticeable, and coasting seems more effortless than it was. Probably the acid test will be when I do some terminal velocity glides down some hills on my commute - typically I see 80-85kph going down them.

Someone yelled out "What's the go with the car, mate!?" at a set of traffic lights. I said (before doing the testing) "The drag coefficient is about 0.22". He probably didn't know what I meant. I guess I should have said "fuel economy!". Oh well.

I still have had no issues with rubbing.

And I think my solution to the front of the rubber/car join will be industrial strength UV proof clear tape.

Pretty sweet! I'm endlessly impressed by your ability to make improvements and actually get out there and collect the data.

[newtonsfirstlaw]

Originally Posted by SVOboy

Pretty sweet! I'm endlessly impressed by your ability to make improvements and actually get out there and collect the data.

Thanks... although coast down testing is so difficult to do it's almost impossible. I'd treat any figures with a large grain of salt.

With wind, elevation, and temperature all playing a part, it's very difficult to get it right. Especially wind. Every cyclist knows what it's like to get a gust of wind in the face, how that will slow you down very quickly (or enable a longer coast). But you just don't feel it in the car.

Crosswinds are also lethal - wind can be coming from almost any angle except about 30 degrees or so directly behind, either side, and still slow you down.

I should get myself some sort of altimeter before I even do a coastdown test via eyeballing.

However, I do know that there is a definite improvement to all my modifications, and that it is large. I can tell that by the sorts of hills I can coast down now and maintain or increase speed, and the way that my FE has improved to something like 3.7l/100km compared to 4.6l/100km highway. And that's with a combined cycle drive. If it was solely highway, it would be better than that no doubt.

[newtonsfirstlaw]

Originally Posted by SVOboy

Pretty sweet! I'm endlessly impressed by your ability to make improvements and actually get out there and collect the data.

Thanks... although coast down testing is so difficult to do it's almost impossible. I'd treat any figures with a large grain of salt.

With wind, elevation, and temperature all playing a part, it's very difficult to get it right. Especially wind. Every cyclist knows what it's like to get a gust of wind in the face, how that will slow you down very quickly (or enable a longer coast). But you just don't feel it in the car.

Crosswinds are also lethal - wind can be coming from almost any angle except about 30 degrees or so directly behind, either side, and still slow you down.

I should get myself some sort of altimeter before I even do a coastdown test via eyeballing.

However, I do know that there is a definite improvement to all my modifications, and that it is sizable. I can tell that by the sorts of hills I can coast down now and maintain or increase speed, and the way that my FE has improved to something like 3.7l/100km compared to 4.6l/100km highway. And that's with a combined cycle drive. If it was solely highway, it would be better than that no doubt.

[MetroMPG]

(FYI, moved the posts about tubeless tire repair to a new thread.)

[WaxyChicken]

How will you change the tire with the skirt attached like that? it looks like one none-removable piece.

[newtonsfirstlaw]

Originally Posted by WaxyChicken

How will you change the tire with the skirt attached like that? it looks like one none-removable piece.

It only goes up half way, and if you've ever changed a tire, you'll notice that the tire drops down quite a ways when that end of the car is jacked up. In addition, the rubber is pretty flexible considering it doesn't have to bend very much to move outwards.

A professional version of this mod would use some sort of spandex the color of the car, and have a strip going around the outside that would anchor the material and be removable.

[Istas]

Wow! Congrats on going for it, and extra cool on the improvement! Your experience is all the more impetus for me to get moving on front skirts of my own.

[tf4624]

wow you need them custom made LOL