Jumbomax's Grip Pressure & Impact on Range of Motion

[wetzel1592]

Since there’s still snow on the ground, I’ve been mindlessly scrolling and came across Bryson talking about his Jumbomax grips. Going down yet another equipment rabbit hole, I watched a video of him talking about how it helps him stay tight in the fingers and hands but supple in the wrists. 

3.2K views · 23 reactions | Bryson Explains Why He Plays JumboMax...

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Bryson DeChambeau explains why he plays #jumboMaxgrips.

This made me think of this thread on grip pressure. 

Another part I found interesting is them talking about the benefit of being able to have the club in the fingers and in the palms, agin the purpose being to remove tension in the wrists and forearms. 

Here’s a video of Iacas explaining the importance of having the grip in fingers and when you have the grip in the palm it severely decreases your range of motion. 

In theory, it seems like it would provide the ability to keep a firm grip in the fingers while decreasing tension in the unwanted areas. But, is that benefit outweighed with a decrease in your range of motion?

Interested to see if anyone has tried these and what their results were. 

[Clemsonfan]

I used the Jumbomax Ultralight Small for quire a while. As a former tennis player this felt similar to hitting a forehand, and they were much more durable than the Winn DriTac Jumbos I had been using. I stopped using them when I went to a Wright Balance instructor and they like for their upper core players to use the smallest grips. Since then I have been using GP Tour Velvet +4s. 
 

I was a big fan. I don’t have large hands but can palm a basketball. I use a ML glove with most brands. With the JumboMax, my fingertips just touch my palm when I take my grip.

[iacas]

On 1/25/2025 at 11:01 AM, wetzel1592 said:

In theory, it seems like it would provide the ability to keep a firm grip in the fingers while decreasing tension in the unwanted areas. But, is that benefit outweighed with a decrease in your range of motion?

I don't think that part is necessarily true at all. And his screwdriver thing made little sense. Screwdrivers with thicker handles increase the moment arm, so the same amount of force creates a bit more torque, but that's the only reason you might squeeze a bit less firmly, but only because of the mechanical advantage you get.

That's not the same as what you need to do in golf.

There are a lot of things that seem like common sense that are almost more the opposite. This may be one of them.

[saevel25]

On 1/27/2025 at 7:27 PM, iacas said:

That's not the same as what you need to do in golf.

Maybe this is what you were getting at? 

Doing some math. Comparing JumboMax versus Tour Velvet, standard size in both. 

I got the force required using the JumboMax grip, to achieve the same rotational acceleration as the Tour Velvet, is about 1.37 more for the JumboMax grip. Interestingly, the Jumbomax grip is about 17% larger than the Tour Velvet, and 17% lighter for the standard size. I just substituted out the radius and mass of the JumboMax as a ratio of the Tour Velvet's mass and radius. This allows me to cancel out the mass and radius and get a ratio for the force.

If you need 100 (force units of your choice) to achieve a certain rotational acceleration, you will need 137 (force units of your choice). 

There was another thread on the forum about offset, where it basically just delays closure by some stupidly small amount. A lot of fun math there.  Most golfers have to go from about 90 degrees open clubface at A4 to square at A7. So, having a grip that requires more force to close that clubface might not be the best idea pending the golf swing. 

A question is, since the clubface is open at A4, and square at A7. Does that mean you want most of the closure to happen from A4 to let say A6, and not A6 to A7, for better consistently (less timing at impact). Just a thought.