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Review: CushCore Pro Inserts allow crazy low tire pressures for more grip, less fatigue

cushcore pro tire inserts reduce arm pump reduce vibrations
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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 its athletes have claimed 7 Downhill World Champion Titles and 20 World Cup Downhill Wins. It seems the Loic Brunis 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 by dropping your tire pressure a little. I refer mainly to the increased traction, reduced rider fatigue and a smoother ride.

cushcore pro 27.5" tire insert on nukeproof alloy rim enduro setup

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, I’ve been running obscenely low tire pressures without flatting (largely… more on that later).

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 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 intact. 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.

Can I switch out a heavy casing tire for a lighter casing if I use CushCore Pro?

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

Sadly, no. When I originally published this review after three weeks of testing on a DoubleDown casing tire, I was happy to report that my Nukeproof Horizon V2 Alloy rims were still in great condition. After removing the CushCore Pro from the rear tire and inspecting the foam I had counted no fewer than 22 cuts 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

More recently, I’ve been running a CushCore Pro on the rear wheel with a lighter EXO+ casing Maxxis DHRII. Running 20-22 PSI, I suffered several pinch-flats on the faster rockier trails of the valley, and on the Fort William Top Chief Enduro Track. The latter experience also put a flat spot in the Horizon V2 rim, too. Having switched back to a Double Down casing, I’ve been puncture-free ever since.

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

The reality is that CushCore says 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 tends 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 uphill 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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11 Comments
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Dan Bacon
2 years ago

Here’s a technical analysis on the design and novelty for those that are interested in the details.

https://wheelbased.com/2021/05/03/insert-for-a-pneumatic-tire-by-cushcore/

adilosnave
adilosnave
2 years ago

At what point should you just get a set of Tannus solid tires? Always thought they probably ride horribly but would go a long way in helping you make through Paris-Roubaix without an inopportune flat.

Robin
Robin
2 years ago
Reply to  adilosnave

No, Tannus tires would be absolutely wrong for Paris-Roubaix or any ride where you want to maximize grip, comfort, or both.

adilosnave
adilosnave
2 years ago
Reply to  Robin

Why? It’s a brutal race so it’s not like anyone is expecting comfort. I just figure that eliminating the chances of flatting would help a LOT if you care about a high placing.

Are you thinking the grip would be poor due to how they compress as compared to pneumatic? I could see that. Supposedly the Tannus tires attempt to replicate various tire pressures but I’m sure they don’t react the same.

Sammy
Sammy
2 years ago

Nooooo, on behalf of anyone that has to submit broken carbon rims to the manufacturer, please stop suggesting even LOWER tire pressures. Ugh

Tom
Tom
2 years ago

I’d call myself a solid technical rider in heavy east coast woods with tons of rocks and roots. When I was riding tubes, I needed 25 psi front and 30 psi rear to keep from pinch flatting. Now on wide rims with real 2.6″ enduro casing tires, I can reliably run 14 psi front 15 psi rear without any inserts, and it’s a game changer. Might be tempted to try an insert, but $150 is a bit dear. If this gets popular, likely someone will knock it off and charge $60 or $70. I know I’m not as fast as some guys on the hairy downhills, but I’m too old to take big chances anymore.

paquo
paquo
2 years ago

I have heard that if you get a flat there is no way to install a tube, not that i have gotten a flat lately

borntobemiled
2 years ago
Reply to  paquo

@Paquo I wouldn’t say no way. No mess free way perhaps. Worst case scenario would be pulling the bead off one side (you’d need to anyway), pulling the cushcore off the rim, pulling the valve stem, installing a tube, and pocketing the valve stem and throwing the messy cushcore over a shoulder like a bandolier. Elegant? Not. even. close. Messy? Absolutely if your sealant hasn’t all dried out. But doable? Also absolutely. But it would likely have to be a cut so big you couldn’t seal it with a bacon strip and at that point and even then, you could conceivably ride/walk it out with the cushcore intact. I can’t believe how much stiffer my sidewalls are even without air and the cushcore installed.

Frederico
Frederico
2 years ago

I went from DH casing tyres with tubes to cushcore with singleply tyres. Got more grip even with harder compound, less likely to damage rims especially in the rear and it’s a lighter setup! I now run 14-17psi front and 17-20psi in the rear depending on terrain.

Matthew Conti
Matthew Conti
1 year ago

So for the record I am using the Cush Core Pro inserts in Maxxis DHF/DHR 2.8 tires got a slice flat in rear, ZERO chance of getting a tube in trail side. Shop #1 charged me over $200 and barely got the 2.8 tire off and new 2.6 on the rear. Next morning tire is flat again but the problem now is neither bike shop in Hood River can get the 2.6 Maxxis DHR II tire off cause the PRO CC inserts are too big – it’s an unending Halloween Nightmare to which I have no solution. May end up cutting brand new tire off just to get rid of the stupid Cush Core insert. RUN DO NOT WALK AWAY FROM CUSH CORE – WORST BUY EVER…between the insets / tires / bike shop charges I’m into my most recent flat tire over $517

Brook Raymond
Brook Raymond
1 year ago
Reply to  Matthew Conti

It’s a tradeoff in hassle versus ride quality, for sure. To me, hands down, it’s worth the extra trouble. There are important considerations you point out that are often glossed over or omitted in many reviews. As your findings show, don’t expect easy tires swaps. Choose the right tire the first time to avoid needless tire changes and stick with it. Consider another wheel set for different conditions. Treat your tires gently to avoid slice flats. And new, well applied rim tape is good prevention. Realize you will need to learn how to install/remove or find a bike mechanic that can. I plan to run my tires down so don’t mind cutting them off. Besides my dog likes ‘tire toys’ it makes. The trick is to get the tire bead down under the cushcore. It takes practice and patience. If this was a device in your shock that gave the same performance boost, I bet you’d gladly pay $75. I get that it’s hard to pay $75 for a glorified pool noodle, but that’s not the point. I just put a Pro CC on a new 2.5 DHR without tire irons (get that bead down) but it took an hour or so. Hope I don’t regret getting a 2.6.

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