My German magnetic bag on R1150R has never come loose, even when hitting Mexican topes & potholes at speed ! Also negotiated the St. of Teouachan with ferocious winds and no issues. I have formed a habit of wiping the bottom off each time I place it on my tank, not a large problem there. It is like an old friend when traveling! I have it full of everything important to have at hand.
dude if it's out in the open, strap it down. web belts work perfect.
Its all about the magnets and the gap.
There are other resources to be sure including speaker shops but there are magnets out there that can break bones. A poor magnet will lose force but may be able to be recharged. Get a boyscout to help.
Try other google searches for "strong earth magnets" There are pull forces way beyond the needed value. A 1" x 18" has 60lb pull.
Dimensions: 1" dia. x 1/10" thick
Tolerances: ??0.002" x ??0.002"
Material: NdFeB, Grade N42
Plating/Coating: Ni-Cu-Ni (Nickel)
Magnetization Direction: Axial (Poles on Flat Ends)
Weight: 0.341 oz. (9.65 g)
Pull Force: 60.45 lbs
Surface Field: 2490 Gauss
Brmax: 13,200 Gauss
BHmax: 42 MGOe
Our 1" diameter disc magnets in 1/10" thickness. Useful for a wide range of applications.
DX0H1: 1 for $1.70 10 for $15.60 25 for $36.50 50 for $68.00 100 for $131.00 250 for $315.00 500 for $580.00 1000 for $1,090.00 2500 for $2,550.00
i use a roadgear magnetic bag, but use one of those shoulder straps you seem to get with every briefcase and loop it under the steering stem.
when it's time for gas, i just stick the bag to the side of the tank.
Go soothingly through the grease mud, as there lurks the skid demon.
'67 Trail 90 || '86 R80 G/SPD+ || '97 F650ST || '00 1150 GS || '06 HP2e || '07 Xchallenge || '14 Grom