For future work when using hand drill. Start with a centering bit. Drill countersink first with standard bit, drill through hole second .

 

Huh? Standard bit doesn't have the right tip angle to do a countersink. The cobalt ones I bought have a 135° tip angle for instance. Older plain steel ones are about the same.

Supposedly the type of countersink bit where it's got both the twisty piece to drill the hole, and the countersink part farther up the shaft, works better for hand drilling. Oh well, lesson learned. I don't think I'll replace this "prototype" just so the countersinks are prettier though. Too much work, unless I get a drill press in the meantime.

Pitchers to follow. Going on a test ride in a minute.

 

Plate mounted in place of the SRA3112 adapter.

Side view. Scoots the top case back 3" compared to original setup.

Fit is snug. Doesn't rattle when riding. No sign plate flexed during the test ride, which it shouldn't since I have very little in the top case while riding. It only holds significant weight (helmets) when parked.

Success so far. I'd like to round off the corners more, but that can wait until I have a way to do it neatly.

 

There are a variety of bit tip angles available, but when I countersink in steel/aluminum I am not using tapered screws - I use flat backs.

 

Gotcha. I went with countersinks with this, mostly so I could easily re-use the existing hardware (so-called flat head metric screws, having a tapered/conical head profile). Seemed wise to stick with

It's likely there would have been enough plate thickness to do a recess for a button head screw. Something to consider if I wanted to do another one of these. Or if anyone wants to copy my design, which is OK by me.

The hardest part of the whole project - besides drilling the countersinks - was locating holes accurately. Somehow the holes for the Monokey hardware (2 mushrooms and wedge) ended up offset about 1/8" to one side. I can only tell when looking at the plate from below, with the top case sitting on it.

I'd still like to chop off the plate's corners. I did round off the corners a bit using a hand file. Ditto for the edges of the plate. All were fairly sharp at first, with one having a small flange left over from the cutting process.

 

We did a test ride with the new top case position. Much much better. We could actually stand to be on the bike long enough to find other problems.

She was much more comfortable except that her knees were too bent. It seems as if Suzuki moved the passenger footpegs up and back vs my old Vee. Not sure if there's any way to fix that.

Suspension was a bit overloaded with two of us. However it wasn't nearly as bad as the stock suspension on my old Vee.

I don't think I'll spend a couple thousand bucks trying to make the DL650 good for 2 up, mainly with suspension upgrades. I think instead I'll follow through with the idea of swapping to a Yamaha FJR 1300. We're going to go do a test sit on one this afternoon. Nobody is going to let us do a 2-up test drive, which is understandable, but just sitting on one should help.

 

Most countersunk bolts use a 45 degree head angle. Countersinks are available in a variety of head angles, but they all need to be used at low rpm to get a smooth finish.

The DL650 can be an excellent two-up sport touring machine with minor modification. Just stiffer springs front and rear, with rear rebound run completely full and then back off a 1/4 turn and fork brace made a hug difference for us. I combination transformed the bike.

Of course the seat becomes limiting, but a seat concepts seat kit will fix that.