RIMPACT PRO TIRE INSERTS REVIEW

Review by Robert Johnston

When we reviewed the original Rimpact Insert a couple years back, we came away impressed but the ultimate damping and protection didn’t quite stack up to the best of them in the mountain bike market. Since then, Rimpact went back to the drawing board to conjure up a new model designed to challenge the top spot for the ultimate downhill and enduro tire insert, which led to the development of their dual-density Rimpact Pro model. The Eurowolf was excited to see how their latest offering would fare under the barrage of abuse within his tires out on the trail.

THE LAB
The Rimpact Pro insert sees a dual-density design approach to offer their ideal blend of performance characteristics. When seeking more protection and vibration damping, simply increasing the density of their original foam turned out not to be the solution as it would increase the energy transmission through the insert and lead to more harmful forces felt at the rim. Instead, they’ve taken their original insert and replaced the outer portion with an energy sensitive strip that shares some similar properties to D3O protective material, remaining flexible until a hard impact causes it to stiffen and distribute the load through the softer foam below. By using a small amount of this denser material, the transmission of forces through to the rim is limited and added weight is kept to a minimum, but they were able to achieve the protection and damping they were seeking. Crucially, the flexible nature of this energy sensitive material in its rest state means the Rimpact Pro should be able to be manipulated easily enough for installation without a major headache.

The result is the 154g (29”, actual) Rimpact Pro insert that’s compatible with 23-35mm rims and 2.3”-2.6” tires. Much like the original Rimpact, the Pro is a high volume insert that sits snugly against the rim bed and fills a large volume of the tire, pushing against the sidewalls but allowing for some air volume between the tread and its top surface to ensure the tire is still able to conform to the trail. This should offer some support to the tire carcass under cornering and g-outs, preventing the tires from folding or burping air. Maintained from the original model is the closed-cell foam that won’t absorb sealant (though they still recommend adding 25% sealant to account for the insert being coated), and the need for an insert-compatible valve to prevent the air channel from being blocked. They’re available in 27.5” or 29”, with a mixed option available to purchase for those mullet-lovers, and retail at £69.99 (approx. €82 /$95 at time of review) with their Rimpact unblockable valves.

THE DIRT

Pulling the Rimpact Pro inserts out of their all-cardboard packaging (kudos to Rimpact for going down the recyclable route), you’re left with a heavily deformed shape that needs a bit of coaxing back into their intended circular form. The energy sensitive material layer has added a good chunk of stiffness to the overall structure of the inserts; however, they do bend back into shape easily enough. It’s important to do this before trying to fit them, as you’ll be thankful for anything you can do to aid the process. Once roughly circular, fitment is the same process as many inserts, but the volume and relatively stiff overall profile of the Pros means there’s a couple steps you can or should take to make your life a little easier. The first of which is to fit the tire without an insert, “pop” the bead up onto the rim then carefully let the air out and only de-bead one side of the tire, leaving the other still in place up against the rim sidewall. This creates the most volume within the tire to squeeze the insert into. Next you stuff the insert in and push it as far over to the beaded side of the tire as possible, working the unbeaded side of the tire onto the rim bit-by-bit as you do so. I found that once I reached a certain point, the opposite side of the insert had a tendency to pop back out of the tire as it’s a tight fit to the rim, so you’d end up chasing it around the rim. A simple solution to remedy this was to affix a toe strap tight around the first portion of beaded tire and work away from this until the remainder was on the bead. This made life a whole lot easier and resulted in a process that takes no longer than most of the competition.

These days I seldom ride a mountain bike without an insert in the rear at least, settling for tire pressures in the 23psi front and 25psi rear range for typical rides with the likes of the Nukeproof ARD’s. Comparing the two directly, there’s quite a change in the ride feel, with the Rimpacts feeling considerably more involved in the ride and producing a significantly more damped and muted feel. Going down towards the 19F/22R psi range – lower than I tend to enjoy going – the Rimpacts continued to offer impressive levels of support and comfort, but things began to feel quite slow rolling. Perhaps the increased involvement of the insert down at these pressures was beginning to prevent the tire from deforming to rocks and roots on the trail quite so actively creating the hindered rolling characteristics. However, the protection remained, with only a couple of instances where it was clear the insert had reached full compression and started transmitting some real forces to the rim, but even through these instances everything was very muted, and I couldn’t damage the rim. I began to aim myself directly at chunky rock gardens in the name of science, and these notions ran true. Upping the pressures a few psi helped to sort the rolling resistance whilst retaining most of that muted trail feeling. Over a few tire changes, the insert has eased off a touch in its tightness on the rim, but only to a positive level so far where it’s easier to fit but not close to “flopping”. I’ve hit countless square edges, torn a couple tires on razor sharp rocks and generally thrashed them about, and there’s little to show for it.

The Wolf’s Last Word

I’d suggest Rimpact has created a serious challenger to CushCore for protection in their Pro model, whilst tipping the scales at a considerably lower number. The ultimate damped feeling doesn’t quite reach CC levels, but it’s pretty damn close. There’s impressive tire support to resist the vagueness that can come from the seriously reduced pressures you’d be silly not to run, and their price is very competitive in the “premium” insert market. It’s safe to say I’m rather impressed. 

Price: £69.99 /€82* /$95* (*approx conversion at time of review)
Weight: 154g (29”, actual)
Website: Rimpactmtb.com