When the carbon plate arrived, the price arrived with it: a racing shoe became a thing that cost as much as a week away. Then Decathlon’s running brand put one out at £129.99, and the interesting part was not that it was cheap. It was that nothing in the industry’s explanation of why these shoes cost what they cost survived it intact.
The shoe that broke the price
Kiprun is Decathlon’s running brand, and the KD900X was its first carbon-plated shoe. Women’s Running had it at £129.99 at a weight of 182 g, at a time when the shoes it was being compared with sat at two to three times that. The versions since have moved around the same territory: the KD900X LD at £159.99, the KD900X.2 at £119.99, which that magazine called one of the cheapest carbon-plated racers around.
For context on what it was undercutting and why any of it exists, the carbon plate story covers the Monza prototype and the rule that followed.
What the reviewers actually found
Not a giant-killing. Reviewers described the original as firm, not as bouncy as the quickest shoes, and lacking the feel of the top super-shoes. The later LD version was reported as softer, lighter and springier than the first, which is the usual arc of a line getting better in its second and third attempts.
That is a perfectly respectable result and it is the one worth paying attention to: this is a competent plated racer at a third to a half of the price, not a cut-price Vaporfly. Anyone telling you it is identical is selling something, and so is anyone telling you it is nothing.
Why it could be done at all
The price is not a materials miracle. Decathlon designs its own brands, manufactures them and sells them in its own shops, which removes the wholesale margin, the retailer margin and most of what a brand spends to be famous. There are no athlete contracts of the kind the big names carry, no campaign, no shelf to rent in somebody else’s store.
Strip those out and a large part of the gap between £130 and £250 is accounted for before anyone discusses foam. This is the bit I find genuinely useful about Kiprun existing: it puts a number on how much of a running shoe’s price is the running shoe.
What the price does not buy
The plate is the cheap part. A sheet of carbon fibre costs what it costs, and it has been affordable for years. The expensive part of a super shoe is the foam – the PEBA-based midsoles that return the most energy are the costly ingredient, and they are also, as the research on how long shoes last shows, the ingredient that wears out soonest.
So the right question about a cheap plated shoe is not whether the plate is real. It is which foam is wrapped around it, and how long that foam keeps doing its job.
Who should buy one
If you are running a marathon in four hours and change, a £130 plated shoe you are willing to do your race-pace sessions in is worth more than a £250 pair kept in the box for one morning a year. The benefit from these shoes is not evenly distributed, and neither is the anxiety about ruining them.
And if you have never run in a plated shoe, buying your first one at this price is simply a better way to find out whether your legs like it. Mine took three runs to stop complaining.
Questions I get asked about cheap carbon shoes
Is a cheap carbon shoe a real carbon shoe?
The plate is real, and the plate is the least expensive part. What separates a £130 racer from a £250 one is usually the midsole foam around it, and a plate without a responsive foam is a stiff shoe rather than a fast one. Judge it by what the foam is and how the shoe feels at your race pace, not by whether the word carbon appears on the box.
How does it compare with a Vaporfly?
Reviewers have consistently put it below the top super-shoes on feel and on bounce, while rating it highly for the money – the original being described as firmer and less lively than the best. Later versions have been reported as softer and springier. Treat it as a competent plated racer at a third to a half the price, which is a real thing to be.
Is a plated shoe worth it if I am not fast?
Possibly, and the price is what makes the experiment reasonable. The gains measured for these shoes come from running economy, which applies at any speed, but the stiffness also asks more of the calf and the Achilles, and not everybody gets on with it. Finding that out in a £130 shoe is a great deal more sensible than finding it out in a £250 one.