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Replacement forks - boost or not to boost?

thistle_thistle_ Posts: 6,971
edited July 2019 in MTB buying advice
I need* some new forks for my 2016 MTB and want some Rebas.

The boost version of the Reba can be had for around £40 less than the non boost version.
My wheels are currenly 9mm QR, but I can convert them to 15mm (boost or non boost)

Are there any downsides to going for the boost version of the fork and using a non boost wheel in them? A couple of grams extra weight which I'm not going to notice anyway?

(*want)

Posts

  • The RookieThe Rookie Posts: 27,811
    Are you sure your hub will convert to boost, do you have a disc spacer?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • thistle_thistle_ Posts: 6,971
    The Rookie wrote:
    Are you sure your hub will convert to boost, do you have a disc spacer?
    It's a Hope Pro 4. I don't have any spacers etc. yet but I'm aware that I need some.

    I would need the adaptors to change it from 9mm QR to 15mm anyway and there are kits available to convert it to boost, I just need to work out whether I need 2 kits or 1, and whether the wheel needs to be redished as well.
  • steve_sordysteve_sordy Posts: 2,438
    The 15mm conversion caps only convert from 9mm skewer, they will not close the gap between the 100mm gap on your existing forks and the 115mm gap on your new forks. You will need two spacers, one each side. I don't know if you can get them, but they may be available, because I've never looked for myself.

    Also, think about where the disc is (mounted on your wheel), and where the calipers are (mounted on your fork). The calipers are now 7.5mm further out and you will not be able to get the disc in (hence the comment from The Rookie).

    If you can sort out the above, then you will also need a longer skewer than your current one, (by 15mm).

    Personally, I wouldn't attempt it.
  • JBAJBA Posts: 2,852
    Get boost forks for future proofing and either a new front wheel or a new front hub and build your existing rim on to it.
    Then sell the Pro4 hub. There is always a market for Hope hubs and although 100mm is dying out in the MTB world most road and CX bikes are still 100mm.
    “Life has been unfaithful
    And it all promised so so much”

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  • The RookieThe Rookie Posts: 27,811
    They do state that the pro4 can be converted to Boost
    https://www.hopetech.com/products/hubs/ ... -hub/#tech
    "Conversions available for QR, 9mm, 12mm, 15mm, 20mm, Torq and Boost" although I can't see where they sell that conversion, it will need a wider 15mm adaptors and 5mm disc spacer.
    Interestingly it's not mentioned in the tech doc either, so maybe its erroneous in that tech summary.
    https://www.hopetech.com/_repository/1/documents/Pro-4-Front-Hub-Assembly(1).pdf
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • whyamiherewhyamihere Posts: 7,677
    The Pro 4 can be converted to Boost. I've recently done it with mine. You fit a longer spacer on one side and redish the rim by 5mm.

    Bear in mind that new Boost Rebas may have Torque Cap compatibility. What this means is that the pocket the hub fits in is larger, around 30mm diameter. This means that it's a pain in the censored to fit the wheel, as you can't just sit the end caps into the pocket, instead you have to hold the wheel at exactly the right point to slide the axle through. Hope do a Boost converter for Torque Caps though. I've just bought a set and will be fitting them to the bike tomorrow. This obviously doesn't give the stiffness gains (though I doubt they exist really on a Reba), but it should mean that fitting the wheel is as easy as without the stupid Torque Cap compatibility.
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