Let me qualify that. We have tried the Triple Bob from Grin Technologies with all of the Reention shark-type cases we use and most of the Hailong shark cases and it dramatically improves the strength and rigidity of the mount every time. We are now recommending them with all of our downtube batteries. While they improve every mount, they are most important on Jumbo Sharks and Mega Sharks. These weigh from 9 to 12 lbs and are taller so there is more side to side leverage pulling on the mount. With a Triple Bob, the battery is on there rock solid and doesn't move.
The problem being solved comes from the fact that the bottom of these batteries is flat and the downtube is round. This leaves only a few M5 bolts to hold the entire weight of the battery against any side to side forces. This often leads to a battery that "wiggles" from side to side or in some cases "flops" from side to side even with the bolts fully tightened.
The ingenious cure Grin came up with is to provide a V-shaped trough in the bottom of the Triple Bob. This allows 2 contact points the length of the Triple Bob on the round bike frame about 15mm apart to provide a stable platform for the battery. They also raised the threaded bolt holes for the battery mounts to perfectly fit the recesses in the mount so the bolts tighten down snugly with no gap between the battery mount and the Triple Bob. Here is a link to a Grin Triple Bob video.
There are slotted bolt holes to mount the Triple Bob to the water bottle mounts in the down tube and four different hole combinations so the Battery can be moved around up to 4 inches from the water bottle mounts to accommodate different battery positions on the downtube.
For even more flexibility in mount location and dramatically added strength, the Triple Bob also comes with recesses for hose clamps. It even includes 2 different sizes of high-quality stainless steel hose clamps. They even include some flat shrink tube to dress up the hose clamps for a clean professional look that also protects the frame. You can put up to 3 hose clamps on each Triple Bob. Two is enough by themselves or one for extra strength if you are also using the water bottle mounts.
There is one other cool feature I should mention. At one end of the Triple Bob is a chamfered, counter-sunk, bolt hole like the other ones but this one takes a flathead screw, also included. This can go under a part of the battery mount that is flat such as the part on some batteries that holds a controller or the part where the power connectors are located.
Another use for the Triple Bob is to mount a downtube battery in the smallest space possible on a frame that has no room to take the battery on and off once it is mounted. This is a more or less permanent mount. To do this first attach the battery mount to the Triple Bob. Then attach the battery to its mount and lock it in place.
Then position the battery in the frame and lock it down with hose clamps through the Triple Bob. We do this all the time to install batteries in frames that are a tight fit with no room to take the battery off once mounted. We used to do it with zip ties and holes drilled into the battery mount but Triple Bob's are so much better.
If your downtube battery is a little or a lot wiggly, there is a cure for that. :)