Evaluate: CushCore Professional Inserts enable loopy low tire pressures for extra grip, much less fatigue

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By far and away the most expensive tire inserts on the market are CushCore Pro, priced at an eye watering $149 per set. That’s a lot of dollars for some puncture protection, right? But that’s the point, these tire inserts offer far more than just anti-pinch flat protection…

The list of claimed benefits (published on the CushCore website) is comprehensive; smoother ride, more control, reduced rider fatigue, faster cornering, more traction, no tire roll, improved suspension, faster rolling, and of course, rim protection and flat tire prevention. 

cushcore pro review jessie-may morgan
Photo by Finlay Anderson

The number of accolades associated with CushCore is quite frankly astounding, particularly on the Downhill circuit. The brand and their athletes have claimed 7 Downhill World Champion Titles and 20 World Cup Downhill Wins. It seems the Reece Wilsons of this World get on with the product; at least, it certainly isn’t holding them back.

That’s all well and good, but can something that adds 263g per wheel have performance benefits for us mere mortals? My experience over a three week period would suggest it can. Here’s why I think CushCore is one of the best upgrades you’ll ever make to your bike.

Review: CushCore Pro Tire Inserts

cushcore pro review test with maxxis assegai tire
Photo by Finlay Anderson

Some of the above-mentioned claimed benefits of CushCore, with the exception of “no tire roll” and the rim and puncture protection stuff, can largely be achieved through dropping your tire pressure a little. I refer mainly to the increased traction, reduced rider fatigue and smoother ride.

cushcore pro 27.5

The issue of course is that, by dropping your tire pressure, you leave yourself at risk of a number of undesirable consequences; pinch flats, dinged and/or cracked rims, tire roll, tire burp and, on occasion, ripping the tire off the rim entirely. The point here is that, with CushCore Pro, you can run obscenely low tire pressures without risking the above.

CushCore market their product with a tonne of both in-house laboratory testing and independently acquired experimental evidence backing up their claims. In these test scenarios, whether testing rolling resistance, impact protection or vibrations, a standard tubeless tire was pitted against that same tubeless tire running a CushCore Pro insert; crucially, both tires were running the exact same pressure.

cushcore xc tire insert cut out profile tire
A cutaway of a CushCore XC insert sandwiched between a tire and rim (from SeaOtter 2019)

So, CushCore can deliver all of these great performance benefits without dropping the tire pressure. The company don’t use “reduced tire pressures” as a selling point, but perhaps they should. I would argue, and I know many others would too, that these benefits are greatly enhanced with reduced tire pressures.

Before we get into the nitty gritty of my experience, let’s take a step back and look at the tech specs of the CushCore Pro Tire Inserts…

CushCore Pro: The Specifications and Installation

cushcore pro on nukeproof horizon rim
A CushCore Pro Tire Insert positioned on a 30mm internal width rim (Nukeproof Horizon V2)

CushCore Pro Tire Inserts are marketed at Trail, Enduro and Downhill applications, recommended for rims with an internal width of 22mm-35mm, and tire widths of 2.1″ to 2.6″. We measured the inner rim channel portion of the insert at 22mm wide, so fitting these to rims any narrower than that is unlikely to be viable. 

cushcore pro mtb tire insert reduces arm pump rider fatigue

CushCore Pro  Tech Specs
Width 57mm
Depth 22.5mm
Rim Channel Width 23mm
Weight (27.5″, no valves) 257g
Sealant Channels 4 (two on each side)

They’re made up of a closed cell foam, so don’t absorb tire sealant. You’ll see there are two channels on each side of the insert, designed to allow sealant to flow freely. 

cushcore pro sealant flow channels tire insert closed cell foam

Disclaimer: I didn’t actually install the CushCore Pro inserts myself. I’ve a hand injury from, you guessed it, crashing my mountain bike. To avoid aggravating the ligaments, I trusted Norco Factory Mechanic Lewis Kirkwood to install the tire inserts for me. Thanks to the sealant channels, 30ml was all that was required to seat the tires.

Dropping Tire Pressure with CushCore Pro

cushcore pro review on nukeproof wheelset maxxis tires
Photo by Finlay Anderson

I ran the CushCore Pro front and rear on a 27.5″ Nukeproof Horizon V2 Alloy Wheelset with a Maxxis Minion DHR II Double Down tire on the rear and a Maxxis Assegai EXO+ on the front. So, without any tire inserts, I usually run around 20 PSI in my rear tire and 18 PSI in the front. I’m 60kg soaking wet, so I get away with running pressures that are far below what tire manufacturers recommend anyway.

I heard a lot of hype about CushCore before testing it out for myself. My coach runs a set on his enduro bike, running 12 PSI in the rear and just 8 PSI in the front tire. While he’s a shredder, he’s not a Pro. Lewis Buchanan on the other hand is; he’s been running just 9 PSI front and rear and it made him faster on some of his local tracks; check out that video here.

I digress. The point I’m trying to make is that many riders who try it say you should drop your tire pressure significantly to get the most out of the inserts. So, I went ahead and dumped a load of air, starting out with 12 PSI front and rear; a pressure I wouldn’t dream of running on a standard tubeless setup for fear of tire roll and burp, etc.

cushcore pro review riding rocky trails 12 psi
Photo by Finlay Anderson

Heading to a local rocky track on a very steep hillside, I got my first ride on on the CushCore Pro inserts. I rode tentatively at first, in the knowledge that I had just 12 PSI in each tire. The first thing I noticed was… well, nothing. With the CushCore Pro, I certainly didn’t feel any negative effects of dropping my tire pressures by 40%.

On these short, slow speed, steep tracks, I was unable to get much of a feel for what the CushCore was doing. The bike certainly felt very composed, the ride comfortable, and the traction very good; all things I would expect from running softer tires. It wasn’t until I took to the longer, faster enduro and downhill tracks of the valley that the major benefits of CushCore became evident.

cushcore pro tire inserts reduce arm pump reduce vibrations
Photo by Finlay Anderson

On a 4-5 minute local race track, I was stunned by how much fresher I felt at the end of a full, flat out run. The reduction in fatigue I experienced running CushCore Pro was somewhat incredible. I’m stood at the bottom of the local downhill track thinking “where’s that arm pump I usually have?”, and “why do my quads feel fine?”, and “WHAT IS GOING ON?”. Looking down, I see no evidence of tire burp; no sealant leaking out the sides and rims still happily in tact. I’m delighted.

cushcore pro cornering grip
With CushCore Pro, I had no qualms with confidently putting the tire on its edge at 12 PSI – Photo by Finlay Anderson

Traction was noticeably improved too, especially on off camber lines through the loam. I found myself hitting new lines with confidence and composure. To be fair, that could also be as a result of feeling less fatigued, rather than having anything to do with traction. Either way, the feeling of confidence was there and the traction was certainly not lacking.

cushcore pro testing 12 psi
Photo by Finlay Anderson

Over rough sections of track, the CushCore was certainly pulling its weight, taking the edge off bigger hits, encouraging me to smash through rocky sections in the knowledge that I:

  1. Wasn’t risking a pinch flat
  2. Would be able to handle the impacts without being bounced off line

And that brings me to another point; the CushCore seems to damp the rebound of the tire too. In situations where I’d normally expect to be thrown off line, like when you clip the edge of a chunky rock, I noticed I was able to hold the intended line with composure.

Going back to a standard tubeless setup

You never know what you’ve got til it’s gone, right? While I initially felt the fatigue reducing effects of the CushCore Pro acutely, as I rode the setup more, that “wow” effect wore off as I got used to my new, more comfortable and composed setup. 

cushcore pro review going cold turkey
Photo by Finlay Anderson

I was in for a shock when I swapped out the front wheel for a standard tubeless setup (no insert). After a 4-5 minute run down one of the valley’s more challenging enduro trails, I found that arm pump, sore triceps and general fatigue had made an aggressive and unwelcome comeback.

The disclaimer here is that, while I kept the same rear wheel (save for increasing the pressure back to ~18 PSI), I swapped out the front wheel for a DT SWISS alloy wheel running a Vee Tire Attack HPL tire, and I increased the pressure to ~17 PSI. So, I may be comparing apples with oranges here. But, based on my riding experience, I’m inclined to accredit the return of fatigue with the lack of CushCore Pro and the very low tire pressures I was able to run with it.

Did I destroy my rims at 12 PSI?

cushcore pro review nukeproof horizon v2 alloy wheels
Photo by Finlay Anderson

I’m happy to report my Nukeproof Horizon V2 Alloy rims are still in great condition. After removing the CushCore Pro from the rear tire and inspecting the foam I counted no fewer than 22 dents indicating where the rim had bottomed out on the foam; 16 of those dents were visible on both sides of the foam. Without the insert, several of these would surely have resulted in pinch flats.

cuschore pro tire insert review dents foam after use at 12psi

Why don’t CushCore advise customers to drop their tire pressure?

The reality is that CushCore say you can drop some pressure but they stay away from telling people to drop a tonne of pressure. You can see why, too. Most tire manufacturers don’t recommend you run anything below 25 PSI, which is pretty unrealistic for wet climates.

If CushCore were to advise riders to drop their tire pressures by the 40% I did, they’d be opening themselves up to flack if folk went off and ended up damaging their components. In reality, the amount you may or may not want to drop your tire pressure by will vary from person to person, depending on their weight, bike type, riding style and terrain. 

CushCore tend to recommend riders start by dropping just a couple of PSI, but explore what works for them specifically.

Can I recommend CushCore Pro?

Unreservedly. For me, CushCore has been one of the best upgrades I’ve made to my enduro bike setup… ever. The major appeal to me, especially as a racer, is the massively reduced fatigue I experience on long, rough descents. Going fast for longer? Yes, please!

Yes, there is a not insignificant weight penalty, but I’m quite happy to pedal the extra ~500g up hill for the traction, grip and fatigue benefits to be had on the way down.

Pricing & Availability

A pair of CushCore Pro Tire Inserts will set you back $149. That money gets you two CushCore tubeless-specific valves too; they have holes that direct sealant and air laterally out of the valve, rather than vertically down onto the insert itself. 

cushcore tubeless valves tire insert specific
CushCore tire insert-specific tubeless valves weigh 6g each

CushCore also offer inserts for smaller and larger rim widths. The PLUS version is designed for 32mm-45mm internal rim widths, while the Gravel.CX version is for 19-26mm widths. There’s also a much lighter version for XC; it fits tire widths 1.8″ to 2.4″ and inner rim widths of 22mm to 32mm.

CushCore.com

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