Quietly lurking behind the scenes for just over a year now, 20mm Boost (or OverBoost as we’ve heard it called unofficially) is coming. Yes, technically it’s a new standard, but it’s one that may actually make life a bit easier when it comes to existing and future hub options. We’ve heard rumors that the big brands will be moving to 20mm Boost spacing in the future, and smaller brands like DVO and RST are already there.

Existing 20mm forks already use a 110mm hub spacing, so that number does not change for 20mm Boost. What does change is the spacing of the brake mount. Boost places the brake tabs 5mm farther outboard which gives hub manufacturers more room to space out the flanges for stronger wheel builds. But just as importantly, the change in brake spacing gives 20mm Boost the same dimensions as 15mm Boost which gives forks like the RST Stitch and RST Rebel the option to run either 15mm Boost or 20mm Boost axles and hubs by simply adjusting the diameter of the axle’s insertion. Some forks, like the RST Killah, will be dedicated to 20mm Boost.

That will make many 20mm Boost forks compatible with existing 15mm Boost wheelsets. Even better – since the brake spacing is wider than previous 20mm hubs, you should be able to use older 20mm non-Boost hubs with an adapter to make them compatible with 20mm Boost forks – the adapter will simply space the brake rotor out 5mm. The only thing you won’t be able to do will be to run 20mm Boost hubs on existing 20mm forks (until someone makes an adapter for that as well).

The takeaway? Don’t freak out. 20mm Boost is all positives, offering stiffer wheel/fork systems and easy backward compatibility for most existing wheels.

More tuning options

2019 Formula Selva R enduro mountain bike fork with separate positive and negative air chambers

For a while, most suspension manufacturers were looking to simplify things. We moved to single air systems that auto-filled the negative chamber. SR Suntour stepped back from dual rebound and compression adjustments. All in the name of user friendliness. Now, though, some brands are heading back to denser feature sets in order to give riders more tuning options than ever. Among them, Formula is leading the way with an astounding array of options.

The new Selva R (coming this fall) will work with all of their CTS tuning chips, which lets you customize the compression damping baseline then fine tune it with their standard external adjustments, plus their new NeoPos dynamic volume spacers. What it adds on top of their other forks is a dual-air positive chamber that lets you set the positive and negative chambers independently.

Scott Genius with Fox EVOL shock with Ramp Control knob

Out back, the new Scott Genius gets a proprietary Ramp Control adjustment that lets you choose whether you want the shock to be progressive or linear.

From our perspective, extra settings and controls are a mixed blessing. We love being able to fiddle with things and get them perfectly dialed. But it’s easy to go wrong and end up with suspension that feels terrible. The trick is knowing what you’re doing, what each of the controls means and how it affects the ride. The good news? You don’t have to upgrade to a fork, shock or bike with all the bells and whistles. Stock tunes and the standard adjustments are usually quite good for most riders. The other good news? We have a pretty killer Suspension Set Up Guide that you can download for free.

The flip side of this is what could be coming with Fox Live, also spotted on a Scott. The system puts sensors on the fork and rear triangle, feeds them into a central control unit, then automatically adjusts the rear suspension to the terrain. Or at least, that’s the idea…details on that system won’t be announced until some time in August, but the idea seems to be that the computer will do the tuning for you so you won’t have to fiddle with all these knobs.


  1. I didn’t read any of the reasons this article states for a new standard, but I’m outraged by it. Rabble rabble rabble.

    • Most commenters would rather be upset about something than understand it.

      Honestly, how many bikerumor readers/commenters have ever or will ever own a downhill fork? That’s the only people that could possibly be affected, and even then it would have to be someone trying to put new wheels in an old fork – pretty easy problem to avoid.

      But hey, these are people that think the only thing wheels need to do is not fold, so the old ones were fine.

  2. How is RST still in business, and why are they making high end stuff? Never seen them once on the trails in the Bay Area / nor cal. And with names like Killah…I doubt they know who they are selling to

    • RST does not have customer service in USA that I’m aware of. They closed the office recently. Suntour kills it w/ PD mgrs since they have the repair service. Mid range eMTB and entry level mtb bikes all come with Suntour now because of this. RST blew it when they closed the USA service office… short sided thinking of a typical Taiwan factory. DVO “could” dominate if Suntour would give them some of this sport level business.

  3. Why didn’t they leap right to 20mm Boost right away, instead of first giving us 15mm Boost and then 20mm Boost? Heck, why didn’t they give us 25mm Boost right away?

    • boost was designed for 29er wheels, trek made it and you can find the original articles showing how the spacing of the flanges meant the spoke angles were the same as on 26″ wheels. Boost on 27.5 was pointless marketing junk.

      Boost 20mm didnt come because people arnt folding 26in or 27.5 DH wheels, not 29DH has finally come they are making the leap, and screwing over everyone on 27.5 (26 is dead to new DH forks) at the same time, because they can.

    • Built in obsolescence, not wanting to back Trek, cos they can, cos forks are now a grand and seen as a 2 year ownership thing anyway, who knows.
      Pretty stupid how it all moves around though. I don’t care, I have a bike with a 135 wide qr front hub, no standards there either.

    • What, and miss out on conning people to buy twice instead of once? Surely you jest…..

      In all seriousness though, all these “standards” that are not standards, or last for a couple years at most may look good in the short term bottom line, but eventually will bite the whole bike industry in the butt and will eventually drive away the customer base. It’s true you have to have new ideals, but much of the time this crap is change for the sake of sales and new marketing spiel.

      • Do you really think it will drive people away? If you’re dissatisfied with the shifting sands of new “standards”, then you have the following options:
        -quit the sport
        -go singlespeed
        -slowly become retro as your ride gets older and older (but it eventually wears out, and the urge to keep up with the Joneses is pretty strong)
        -give in and buy what’s new
        I am pretty sure that the final option is the one most will choose.

          • @blah- I am not talking about what should or should not be. I’m talking about the options that people in fact have. Personally, I ride a bike with a 3×8 drivetrain (and 26″ wheels!), so I clearly have chosen the third option. But at some point, good quality 8-speed cassettes and chainings will be gone and I will need to get something else.

          • I mean, the drivetrain parts I ride have been out of production for fully 19 years. I also ride Suntour XC Pro thumbshifters, which were discontinued in 1995, nearly a quarter century ago.
            If a person rides 10-speed stuff and buys up now, they could hold out as long as I have or longer, but most people don’t think to do that or don’t want to do that.

        • It’s happened in many industries before, no reason for it not to happen to bicycles. These are luxury items, and when it’s not easy to replacement parts or otherwise difficult to repair your luxury item, or you have to pay 4X the price because it’s proprietary, you drive customers away at best, and out of the market at worst.

          My last carbon road bike, I sourced from overseas, because they gave me any BB I wanted, made to real standards, in any color I wanted, at a better price. Will go that way again in the future. No lefty forks, no one off designs that are then abandoned that were called new standards, no creaking bottom brackets, no crap. Hey, but your welcome to try to be “one of the cool kids” until companies go bankrupt due to lack of sales.

  4. I first saw a fork using the ‘new’ 20mm Boost spacing in the Marzocchi booth at Eurobike in 2005. They were very enthusiastic about how much stronger it made front wheels and how that was helping the mechanics of their sponsored riders. That the industry has collectively sat on the standard for 13 years whilst cycling through 20mm, 15mm then 15mm Boost underlines how little the industry is trying to deliver the best product for the consumer. Why deliver upgrades when you can advertise downgrades and sidegrades into market dominance?
    Little rant over, I am looking forwards to production forks that finally use a superior axle to basic 20mm, I might even replaced my 20mm BOS and Rockshox forks… maybe.

  5. Nope not gonna buy anymore new standards. Just gonna wait till they come back around to where I am now. It’s all a big circle getting stiffer and better until it’s too stiff and re invent the best standard front hub spacing. 110mm with quick release…

  6. Who cares, go ride your bikes. Most people I meet on the trails cannot take advantage of the current bike they have. Its sad to see XC riders with 29″ plus boosted hyper super bikes granny riding on over bumps and downhills. Are big wheels better? Depends on what you’re riding. Are fat tires better? Depends on what you’re riding. Carbon/Aluminum? Depends on what you’re riding.

    The last significant improvements in bikes have been dropper seat posts and the quality of air shocks, again, depends on what you’re riding. Everything else is designed to make you envious and drop cash on things you don’t really need.

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