No. The grips are a comfort layer over the handles, not a structural part. A squeezer with bare handles works exactly as well as one with the silicone still on, because the part doing the pressing is a single piece of 304 stainless steel that runs the whole length of the tool. It will feel harder in the hand and it will look less finished. It will not press any less juice.
What the grips actually do
They spread the load. When you press half a lemon, the force goes through a narrow bar and into your palm, and silicone over that bar turns a line of pressure into a patch of it. That is comfort, and for anyone squeezing a dozen limes for a party it is a real difference. It is not strength. The handles are the same metal underneath whether the silicone is there or not.
This is why the grips can leave without taking anything with them. Nothing was holding the tool together except the metal.
Why they loosen
Silicone and stainless steel expand at different rates. Every hot wash cycle stretches the grip a little more than the bar underneath it, and every cool-down shrinks it back a little less than it started. Do that a few hundred times and the fit that was snug in the box becomes a fit that slides. Dishwasher heat does it faster than hand washing, and the drying cycle is the hottest part.
Citrus oil helps it along. It works into the gap between the silicone and the steel and it does not evaporate the way water does, so the two surfaces stop gripping each other and start sliding against each other.
What to do about it
Push them back on and leave them dry. Most of the time that is the whole repair. If a grip has stretched past the point where it stays, take both off and use the tool bare. It is stainless steel with a hinge, and it is no less safe or less effective without them.
To slow it down on a squeezer that still has its grips: wash it by hand, or put it on the top rack and skip the heated dry. Rinse the citrus off rather than letting it sit. Neither of those is a rule we can enforce and neither one is a condition of the guarantee. They are just what makes the silicone last longer.
What one of our own customers said about it
This is the part worth being straight about. Two people have told us in public that their grips came off. One of them left five stars anyway, and wrote:
Rubber handles have slipped off, but the metal underneath is very sturdy and I do not find the rubber grips to be necessary. Extremely sturdy, and I am hard on these things. After breaking several of the cheap grocery store ones, I bucked up and purchased this one. After a year or so of use, I expect this one to last a lifetime.
That is a fair description of what the tool is. The comfort layer is the part that wears. The press is the part that does not.
The honest limit
If you want a squeezer whose grips are guaranteed never to move, this is not it, and neither is any other squeezer with a silicone sleeve over a metal bar. The only design that cannot lose its grips is one that does not have any, which is a harder tool to hold. We chose the comfort and accepted the wear part.
The metal is covered for life. If the press bends, if the hinge gives, if the bowl cracks, that is a guarantee claim and we will replace it. Grips that have slid off are not a failure of the tool, and we would rather tell you that here than have you find out from a support email.
If yours has gone further than the grips
Bent metal, a hinge that has stopped closing square, a gap between the two halves when they should meet: those are faults, not wear. Email help@kensingtonlondon.com with your order number and a photo. The lifetime guarantee on the squeezer covers exactly that, and a photo is the whole claim.