[durdle]

I have a 2011 Speedmaster with the quick disconnect summer screen. Still get some buffeting at 70 + MPH. I've heard the lower wind deflectors will eliminate some/most of this problem. Is there any deflectors that will fit on the quick disconnect supports? Or can any be mounted on the fork behind them? So far, I have not found any which appear to be adaptable to the 2011 which has the different fork/windshield design. Anyone out there done this on the 2011?

 

[Hyates]

I'm not sure about the 2011, but here's what I did:

http://www.triumphrat.net/cruisers-america-speedmaster/167464-finding-lower-air-deflectors.html

H.

 

[Ramo]

I don't know of a lower wind deflector, but I purchased a fly screen from British- customs.com, for my america. Dart fly screen


Sent from my iPad using Motorcycle

 

[RonL]

Check w/ Fast Eddy

http://www.fasteddysports.com/?page_id=3&product_id=76

 

[keithf]

go to your dealer ask him to bring up the thunderbird se on his screen you will then be able to see how they fit the screen my se came with them fitted and mine is the qd screen
ok just went to garage to have a look at mine
the clear bits are bolted to a chrome bracket which is bolted to the lower part of the screen bracket with two small bolts when the screen is removed the bracket that remains on the bike is what they ar bolted onto so they dont come off with the screen
if you have a qd screen take it off and you will find the holes next to where the lower locating thing is

 

[durdle]

Thanks keithf for the suggestion. Went to the local dealer for a look at the Thunderbird lower deflectors. They will not work on the Speedmaster because the quick disconnect is a completely different design. I took a hard look at the Memphis Shades lowers for size, position etc. Everything looked like it would fit under my quick disconnect summer screen. They attach with brackets on the fork tube. Hoping there is no interference with everything else in the area between the lower and upper tube supports. Will let ya'll know if they fit - with pictures.

 

[durdle]

Memphis Shades lower wind deflectors

Finally got the Memphis Shades lowers in the mail. It was amazing that they fit behind my 2011 speedy quick disconnect summer screen . The deflector brackets fit between the upper and lower fork tube supports. The deflector brackets were placed about 65 mm from the bottom of the upper fork tube support in order for the plastic to clear the quick disconnect struts. Hope the following pictures help see how they fit.

Now for the results. The buffeting is almost completely gone !! I say almost completely because there is still a slight amount at 85 MPH and higher. At lower speeds the wind is a consistent flow - still a little windy since my screen is a summer but not "knock around" turbulence
that I had before. I am not turned off by how they look either.

 

[BVA]

Do you have part numbers for the lowers and brackets that you used on the 2011 I have the taller Triumph Screen and would like to get some lowers for my 2011 Speedmaster
Thank you

 

[durdle]

BVA- I got the lowers and attaching hardware from J&P cycles (jpcycles.com). These are for fork diameters 35-43MM. I think the speedmaster is 43MM since I was at the maximum setting on the clips.

HARDWARE - (attaching brackets)
J&P P/N 750-335. Memphis Shades P/N MEM9884 -- $56.99

Clear Acrylic Lowers
J&P P/N 750-272, Memphis Shades P/N MEP5810 -- $24.99

Shipping and handling --7.99

I think these would work as well on the taller screen - perhaps even better

 

[BVA]

Durdle- Thank you very much for the help. I road a couple miles today while the weather was good. I need to order the lowers to stop the buffiting. I think I twill like the Corbin seat and floor boards I installed the other day just need to put some miles on them to know for sure.
Thanks again.

 

[cruisin]

Finally got the Memphis Shades lowers in the mail. . . . The buffeting is almost completely gone !! . . . - still a little windy since my screen is a summer but not "knock around" turbulence
that I had before. I am not turned off by how they look either.

durdle,

Here's something for you to consider to clean up airflow with the fork mounted lowers. I had a similar dilemma when I bought my first R1200C in April of 2000. The windscreen worked pretty good but I still had quite a bit of turbulance from underneath, around the sides and over the top. I presented my problem to a buddy of mine who is a retired Ranger that flew helicopers for a very long time. Those guys really understand aerodynamics.

He first suggested I cut some "big-ole-holes" near the bottom of the screen. I immediately balked on cutting holes in a very expensive windscreen. His next suggestion was much more palatable; "lean it back several degrees", he said. Fortunately, the besign of the brackets made it very easy to accomplish that task.

Here's what happened. By leaning the windscreen back, it opened up about a 40mm gap over the headlight. That gap allows air to pass under the windscreen and eliminates the vacuum created as it passes through the air at higher speeds. The vacuum is what causes turbulance and buffeting. One would think that the gap might cause you to get a blast of air under your chin, but it does not. The air coming under the windscreen gets sucked straight up the back side of the screen by the air passing over the top of it.

I determined the lean angle by getting the screen so I could see about 2" over the top. That resulted in it being about 10* more angle than my front forks. This gave me clean air hitting me just about chin level. That is actually far better than clean air passing over the top of your helmet as it keeps your face shield cleaned off in the event you get caught in a rain storm. I found out years ago on my old R75 that a windsreen being so tall it keeps all wind off your face also allows water to pile up on the face shield and usually on the windscreen too. Now I look over the top of the windscreen and my face shield is pretty much self cleaning from water at highway speeds.

Unfortunately, I still had a fair amount of turbulance coming off my feet, legs & knees. My next step was to add some fork mounted Parabellum lowers (similar to the ones you have). I first tried them per the drawings from Parabellum which showed them to be mounted straight across the forks and perpendicular to airflow. One lengthy test ride made it pretty clear there might be a better way. The darn things vibrated like crazy in the wind and upon checking fuel mileage at the end of that ride, I noted I had lost about 4mpg after gaining about that same amount with the new angle on the windscreen.

I next tried adjusting the angle back on the lowers so they stop an inch short of hitting the wishbone suspension. That resulted in about a 45* angle back from straight across. It cleaned up airflow past my legs so that if I hold my hand down by my knee, I start feeling wind approx. 2" out from it. The added bonus is that I got back the 4mpg plus 3 to 4 more.

All is good with clean air around the windscreen and lowers now with my 1200cc cruiser getting ~50mpg under steady throttle with good weather conditions, (no wind).

Hopefully this picture will give you a clear look at my windscreen and lowers angles.

 

[durdle]

Hey Cruisin
Thanks a bunch for the detailed input. Looks like you did a lot of analysis and experimentation to come up with an excellent way to minimize air flow problems. I would really like to slant the windshield back but the Triumph quick disconnect design will not allow it. I did adjust the lowers a little so that they are not as perpendicular to the air flow. I couldn't adjust them back to a 45 deg. angle due to interference with the bottom of the shield but was able to get more backward slope than I had.

As for putting holes in the windshield, I have seen this mentioned on other forums and the consensus is it works!! Am a little reluctant to do it because I am not sure where to put the holes and how big to make 'um. From the picture it does not look like you did any holes right? Am thinking about 2 inches above the top of the headlight and about 7 inches apart. Would 2 holes about 1 inch in diameter do the job?? What did your friend specifically suggest?

 

[cruisin]

I think he had in mind two large holes near the bottom similar to an older style Goldwing that had 3" holes about 4" up from the bottom of the screen. I think those had louvers in them though to serve as vents directing air at the rider for summer cooling.

It's too bad your windscreen does not lend itself well to changing angles. That one little adjustment worked wonders for me.

 

[roxiedog13]

Durdle- Thank you very much for the help. I road a couple miles today while the weather was good. I need to order the lowers to stop the buffiting. I think I twill like the Corbin seat and floor boards I installed the other day just need to put some miles on them to know for sure.
Thanks again.

+1
Thanks for the part numbers, I was searching for a day now trying to get some numbers without success. The fact that yours worked out a bonus. I have the tall Triumph screen assume it is the summer though it is fixed not a quick release.