Minimizing drag at 140mph+

[Frank]

Cool! How fast did you run?

And can you tell me what size the front wheel is and where you obtained the fender? I need something similar in 16" size. (thanks)

[teoman]

Why not make a suit with the bodywork incorporate?

You could also maybe use covers attached to yourself of some sort that are a flexible material like TPU that you velcro on to the bodywork. A bit like a cape.

[CoClimber]

Not 140mph, that's for sure. My fastest was 61.299mph.

I made the fender the same way I made everything else. Stack 2" foam then cut and sand away everything you don't want. Seal the foam, add mold release, then lay of fiberglass. Because it is a male mold, you will need to smooth the outside. I used auto body filler. It looks good if you don't get too close.

[Frank]

That's what my plan is too but if I could buy something I would.

That's a great speed BTW - (hope you wear ear plugs!)

[freethink]

I'm going to assume you are running in the supersport class, seeing as how you aren't using slicks.

1) Move your transponder somewhere else. Maybe behind the gauge cluster. You still want it as far forward as possible, in case you are neck and neck with somebody at the finish line.

2) See if you can get a front fairing without those funky air channels on the sides. Chances are, if MotoGP guys aren't using funky bodywork, then it's probably just a gimmick.

3) A front fender that extends farther forward over the tire, might be beneficial. It looks like there is a pretty large gap (an inch or so) between your current front fender and the tire, which may act as a air scoop, increasing drag. Maybe you could modify the mounting holes, to get the fender closer to the tire

4) It looks like you already have a taller windscreen, but there are others on the market that look like they may provide better wind protection. I'm thinking of the Zero Gravity Corsa screen. The Sport touring one is even better, but you may run into helmet clearance issues with that one. Perhaps you could get that one and trim it so it doesn't interfere with your helmet.

5) When I used to go down the straights, I would take my hand off the left bar, and grab onto the top of the left fork. That would get my hand out of the air stream, and allow my elbow to get in tighter to the tank. I've even seen some guys put their left arm behind their back to reduce drag, lol.

Unrelated to aero:

5) Perhaps you could clean, polish and re-grease your brake pad retaining pins/sliding hardware to makes sure there is no excess friction. Same thing for your drive chain. Are you running a 520?

6) I hear Daytona is really hard on tires. I think they make special tires for that track to cope with the steep banks.

7) Superbike allows for a lot more modifications. Have you considered moving up?

8) Rider skill is by far the biggest factor in going fast on any track. Practice practice practice. Your riding looks very good though.

[Michael Moore]

CoClimber, congrats in your sucess but your upper body is much too high. Lower the front end, lower your bars, lower your head and try and get your back as horizontal as possible. Remember that you don't want too much taper in the vertical direction any more than you want it on the sides.

Here's a Moto3 bike in a wind tunnel and a big seat being made for a RS125 Honda that was being run at El Mirage.

cheers,
Michael

[Michael Moore]

Originally Posted by freethink

Chances are, if MotoGP guys aren't using funky bodywork, then it's probably just a gimmick.

Chances are, if they ARE using funky bodywork, it is probably just a gimmick too.

It is surprising how, over the last 45+ years, I keep seeing road racers at high levels of competition using really funky bodywork. The details may be "rocket science" but what is needed as a good starting point has been out in the public arena all that time. I've pointed out to many people that a fairing that leaves 4" of rider hanging out all the way around isn't doing much good, though that usually results in a blank stare in return.

A kind of related anecodote: I used to be the North American distributor for John Bradley's two volume set of "The Racing Motorcycle: a technical guide for constructors" (and John is working on Vol 3). I sold copies to all the major manufacturer US branches and John sold plenty of books to national/international level racers/teams. John mentioned that it wasn't uncommon to stop off at a club race to show the books around and get a "meh, why would I want a book like this, I'm a RACER" response. On the other hand, go to a big national/international race and they were an easy sell.

I remember selling a copy of Vol 1 (the book with the aerodynamics/chassis dynamics stuff) to a bike drag racer, and he couldn't see any reason it would help him so I took the book back and refunded his money. Showing V1 to another drag racer (and a much more successful one) had him saying "wow, I'm so going to use this and cut my times/boost my speed at the strip".

You can lead a racer to the river of knowledge, but you can't make him take a drink from it, especially if he hasn't seen whatever you are offering in the monthly magazines.

BTW while Vol 1 & 2 are out of print (John will reprint when Vol 3 is done) there are a few copies of them that show up on eBay now and then, more so Volume 1 than V2. The page with results from wind tunnel-tested modifications to the Can Am 125/175 LSR bikes is very interesting.

cheers,
Michael

[freethink]

"Chances are, if they ARE using funky bodywork, it is probably just a gimmick too."

-Not sure what you mean by that. I don't think you'll find much of any gimmicks on GP bikes.

"over the last 45+ years, I keep seeing road racers at high levels of competition using really funky bodywork."

-Neither of the current model MotoPG, or Moto2 bikes have those 'funky' channels down the sides of the front fairing that the R6 has.

[Grant-53]

I plan to restore and streamline a 50cc Honda elite scooter. I'm just down the road from CoClimber.

[gumby79]

teoman

5.2.12 No streamlining may be attached to the rider.

freethink. 1) Move your transponder somewhere else. Maybe behind the gauge cluster. You still want it as far forward as possible, in case you are neck and neck with somebody at the finish line.

A

5.4..2.....The ESU is considered to be properly mounted if it is securely fastened to the right front fork leg, right front fork tube or right side of fairing where the signal can be read by the ground antenna and activated by passing through the activation area..It is the riders responsibility to insure proper activation of the ESU before entering the racecourse.
5.4.2.A. There can be no solid metal or carbon fiber between the mounted ESU and the ground antenna......

Michael Moore: ower your head and try and get your back as horizontal as possible.

A
Permalink#18

As for the helmet and leathers, I really can't modify them per rules. With my chest slammed against the tank, that helmet position is my maximum upward look (actually takes a lot of effort). I am trying to get an unpadded race seat, which should lower my pelvis an inch or more into the bike- as the rest of my body follows, I might get those extra degrees clockwise rotation of the helmet that you recommended.