Bill's GZ250

[BillInGA]

Here is my 2004 GZ250, in classic black. I bought it in August 2006 with 1,100 miles on it.



I have a Cortech Sport tail bag and a Joe Rocket Manta magnetic tank bag.



My windshield is a Slip Streamer SS-28 Sport Fairing.




The view from the cockpit. The GPS is an older Garmin Etrex Vista, attached with adhesive-backed velcro.

Current modifications are: Pilot Screw, Needle Shim and 16T front sprocket.

[Water Warrior 2]

Looks good. Does the windshield provide a lot of protection for your hands in rain and cold ??

[BillInGA]

I can't say yet. I installed the windshield 5 days ago and haven't ridden through any rain yet. From what I can tell so far it deflects the wind from most of my hand, but I still get some wind on the outer 2 fingers.

My hands didn't really get that cold before the I put on the windshield. I have a pair of Firstgear insulated gloves that do a good job of keeping my hands warm. Plus I usually don't go on longer rides when the temperature is below 50 F.

The windshield does deflect the air from my arms and chest, which was my primary intent. The air deflects up to about shoulder height; I can feel some slight buffeting around the top of my shoulders. My head in still in the windstream and it gets the deflected air from the windshield. However, I don't feel any more pressure or buffeting on my helmet than before, but I do get a little more wind noise.

[mrlmd1]

You can try and adjust the rake of the windshield a little up or down to see if it makes any difference, It may take a while of fiddling with it to either make it better or until you give up. It's always some sort of compromise and you will never eliminate the noise and buffeting altogether.

[Water Warrior 2]

Yup, wind noise is hard to get rid of in most cases. I get some on the Vstrom and when I rode Lynda's M-50 I was almost deafened. Thankfully she sits lower so the noise is a bit different for her. My best solution is a cage.

[BillInGA]

I've already made a few adjustments. I'll probably fiddle with it for another week or so before I set it in Loctite. I might raise it up another inch or so, but I think I'm pretty happy with the rake angle.

[mrlmd1]

It should roughly be parallel to the forks.

[BillInGA]

Originally Posted by mrlmd1

It should roughly be parallel to the forks.

I've heard this a couple of times on the forum. It's probably true for slab or "tombstone" windshields from an aesthetic standpoint. From an aerodynamic standpoint, however, I'm not convinced.

Fork rank angles vary from model to model in order to achieve the desired performance goal of the bike. Smaller rake angles (more vertical) provide more maneuverability but less stability and vice versa for larger rake angles. Sport bikes typically have shorter wheelbases and smaller rake angles, cruisers have longer wheelbases and larger rake angles and choppers, well they're just silly.

It's counter-intuitive that you would want a more vertical (and less streamlined) windshield on a sportbike and more swept back on a cruiser. Now, it just may be that the optimum windshield angle on a cruiser approximately matches its fork rake angle. I'll have to do some more research and experimenting to see what works best for me.

[Easy Rider]

Originally Posted by BillInGA

I've heard this a couple of times on the forum. It's probably true for slab or "tombstone" windshields from an aesthetic standpoint. From an aerodynamic standpoint, however, I'm not convinced.

It depends, in part, on what your aerodynamic objective IS. Like you properly pointed out, the rake of the forks is different from bike to bike so the "parallel" suggestion is only a starting point. Rider preference has a lot to do with it too.

I figure that if I have a shield, it should keep most of the wind (and bugs and rain) OFF of my chest AND head. There are only 2 basic ways to do that: Have a tall shield OR have the rake angle small (more straight up)......or a combination of both.

Alas, when you don't have much raw horsepower to play with, your options are somewhat limited.
I have screwed with shields for the better part of 40 years and THOUGHT I had it figured out right........until I got the little GZ. I didn't realize until right before I sold it that with limited power, I had to bring the shield up higher and tilt it at more of an angle..........OR sacrifice about 5 mph off my top speed (this is with a wide shield). I think I really should have had a somewhat smaller shield for that particular bike.

Enter more CCs....and the "ideal" height and angle is back again but this time I am likely sacrificing a little fuel mileage instead of top speed. Those who can stand a little wind in your face shouldn't have quite so difficult a time getting it "right".

If I remember your situation correctly, I think bringing the shield up a bit higher and standing it up a bit straighter will be the solution. Then again, sometimes when you do that, the rush of air BELOW the shield then becomes objectionable. It is a seemingly never ending battle.

I am about to take mine to a plastics shop and have the lower tabs BENT so I don't have to get "lowers". :roll:

[BillInGA]

Originally Posted by Easy Rider

It depends, in part, on what your aerodynamic objective IS. ...

Truly stated. My primary objective is to shield my torso and arms - so far accomplished. I intended to leave my head in the slipstream, hence the choice of the shorter windshield. My reasoning is that a full-face helmet will produce less drag than diverting the air over my head. If I can decrease the wind noise any more that would be great, but I'm pretty happy with the overall results so far.

I have noticed some air come up from below the windshield, but my tank bag does a good job of blocking it. In fact, I didn't even notice it until I saw my garage door opener key fob flopping around.