Anyone who knows me and has talked about bikes with me will know I talk a lot about CushCore.
In my opinion, it’s one of the best bike inventions since dropper posts or disc brakes. “But why is it so good” you ask? Well, let me explain.
CushCore does several things:
CushCore is a properly engineered product and so much more than other ‘pool noodle’ type inserts from other companies.
Impact Protection
Everyone thinks this is the only point of inserts. Whilst it is indeed a positive quality, the other aspects are so much more important to performance. Other tyre inserts tend to only address impact performance.
I believe the other benefits of CushCore are so much more important that I have run bikes with only a front tyre insert before, where the added grip and control are most needed.
Sidewall Support
CuschCore pulls tight against the rim and extends up a portion of the sidewall. In hard cornering, it supports the tyre and reduces it from rolling.
Increased Grip
Tyre contact patch is a function of pressure in the tyre and nothing else. A lower pressure needs a bigger contact patch to support the weight of the bike and the rider. So low pressures are good, except they often lead to rim damage and tyre roll. CushCore allows you to run super low pressures reducing the effect of the negative aspects.
You can run some very low pressures for super grip. The only limit tends to be tyre roll. As much as CushCore helps reduce tyre roll, in very grippy conditions and surfaces, very hard cornering will try to roll the tyre off the rim and you’ll need to add a bit more pressure. But when grip is low, in very muddy sloppy conditions, you can just keep dropping pressures.
In a race a while back, I ended up running 10psi in the front tyre to find grip in super muddy conditions. There was one off-camber and tricky high line that only some of the Elite riders could stick. But “fastest of the duffers” rider that I am, with the aid of low pressures and CushCore I managed to stick the line too, riding well above my pay grade!
Lighter Tyres
The additional support, protection and damping of the CushCore system allows you to run lighter weight tyres than you normally could. This offsets any weight that the inserts add to the wheel.
In fact, on many of my personal bikes I am now running light weight 2.2″ trail tyres with CushCore XC, running them at the sort of low pressures I would expect in an enduro tyre. It works great!
Tyre Damping
Tyre damping is something I’ve been thinking about for a long time. I even applied for a patent on a system I had developed over ten years ago. Unfortunately, my idea had already been patented in 1935, so people have been thinking about the problem for a long time. And unfortunately, it had some fundamental flaws!
Currently, we have say 150mm of suspension in our bike controlled with very expensive and tuned units. We could talk for hours about the relative pros and cons of different systems and solutions, it is well understood.
However, attached to the end of this system, we have say 25mm of tyre suspension. This is at the most cirital part of a bike, the contact to the ground. This 25mm of suspension only has minimal damping in normal trail tyres, and not much more (but a noticeable amount) in DH tyres. Discussion on this particular subject would not go far with most riders.
See System (1) in my diamgram. Why do we not have damping in this crucial part of our suspension system? Damping would stop tyres rebounding off obstacles and improve grip. See System (2).
Watch any slow-motion footage of someone jumping into a rough rock garden (as well as all the slow mo huck to flat videos loved by bike testers). The first thing their tyre does is rebound off the ground. There tends to be several rebounds before it settles. The suspension cannot deal with this.
Imagine a case where the tyre sticks to the ground on the first bounce.
How much more control would we have?
CushCore doesn’t yet offer this level of damping. But it adds much more than tyres alone can achieve!
Ex-aerospace engineer Joe Mcewan is the founder and chief engineer of Starling Cycles. Passionate, outspoken and fond of a cuppa and a debate, Joe loves to challenge the established thinking of the industry.
