EXT Racing Shox expands line of Super Alloy Racing shock springs

When I first started racing down hill mountain bikes, I remember reading through bike magazines and lusting after titanium shock springs. They were beautiful, they were light, they were… outrageously expensive. Especially if you needed to change up your shock tune and go to a heavier or lighter spring. The price is probably the main reason that titanium springs remained a factory option or one for the well-heeled privateer.

These days though, there’s a new spring on the block. Instead of pricey titanium, a number of manufacturers have utilized a new lightweight class of steel spring. Many of them, including the EXT Super Alloy Racing Spring from EXT Racing Shox promise titanium spring weight – at 1/3rd of the price. Now, EXT has expanded their range to fit almost any mountain bike shock, providing another option to drop a few grams…

Designed to fit with popular brands of shocks including RockShox, Fox Racing Shox, Öhlins, Cane Creek, Marzocchi, BOS, DVO, and X-Fusion, the springs are available from 225lb to 600 lb versions in 25 lb increments. EXT Racing Shox claims these are the lightest weight steel springs available, but the Cane Creek Valt springs seem like they might upset that claim, though we can’t confirm since Cane Creek doesn’t offer individual weights. Priced at €98-115 with the adapter running another €10, they’re certainly less than most titanium springs.


  • Super Alloy Spring (proprietary super-light design)
  • Extreme Linear Ratio
  • Hard Epoxy Coating
  • Internal Diameter: Ø38.5 mm
  • Length: 105 – 110 – 140 – 175 mm
  • Stroke: from 50mm to 89mm
  • The lightest* steel springs on the market *claimed
  • Developed in our motor sport racing programs
  • First dedicated to fine tuning with 25lbs increments
  • Today used by the fastest Pro Rider in DH and Enduro
  • Adaptable for all type of shocks in the market
  • Life duration: over 500.000 cycles



11 thoughts on “EXT Racing Shox expands line of Super Alloy Racing shock springs

  1. As someone who doesn’t have much experience with spring suspension what does “life duration” mean? Is the spring at risk of breaking, or does it lose tension below it’s rated value?

  2. technically both, but mostly reduction in spring constant beyond the claimed lifespan (which you referred to as tension). i’ve been downhilling over 10 years and have actually had a coil fail on me, but it was used when i got it, and i rode it a ton.

    also, not the first to offer springs in 25lb increments. K9 race offered high quality steel springs in 25lb increments, but last i heard anything from them was 2014.

  3. actually, my answer to your question was poorly framed (and i misunderstood your question the first time i read it).

    life duration in this context is the number of (compression) cycles a spring can go through and maintain its spring constant.

  4. so how many cycles does a dh’er put on a rr shock in 1 hr of dh’ing? i need ride time hours. something more tangible than compressions…

    1. Isn’t that supposed to be pretty similar across different steels? I’ve been wondering how they get a stiffer spring with less metal on these. Is it a steeper wind with fewer coils, that only a stronger alloy can accommodate?

      1. Steel alloys can be between 190 and 220 GPa, but maybe this “Super Alloy” is higher.
        You are true, with fewer coils the spring is stiffer, but the stress is higher so the alloys needs a higher fatigue life. To have a similar stiffness the spring with less coils needs a thinner section, so the stress is even higher.

  5. Old tech already, theres metal glass/glass metal now.
    Whole load lighter and stronger.
    Look it up, and look for it to be used in everything cool for the next 5yrs.

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