SuperBoost And Flat Mount XTR – Things You Didn’t Know You Needed

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On the same day that Shimano announced its new 12 (and 11 and 10) speed Deore groupset, it is also announcing a few more items, like bigger capacity batteries for its e-bike motors and, well, there are a few things that are particularly niche…

Shiny XTR goodness, only wider…

XTR for SuperBoost Bikes

SuperBoost Plus bikes, like those from Pivot and Salsa run wide, 157mm rear hubs and they accordingly need wider spaced chainlines. Shimano is filling the top end need for chainsets by today launching its new FC-M9130 chainset designed for bikes with 157mm rear hubs.

As Shimano says: To provide the perfect chain line for 157mm O.L.D. rear hubs Shimano is introducing a new front crank. The XTR FC-M9130-1 is a 1×12 lightweight, direct mount Hollowtech II crankset with Dynamic Chain Engagement+ chainrings for excellent chain engagement and retention. The FC-M9130-1 runs on a wider 56.5mm chain line meaning that it can accommodate wider tyres but has a relatively narrow Q-factor of 171mm. This is achieved by using the low-profile arms of the XTR FC-M9100 series, which gives riders the benefits of a wider chain line frame without affecting the biomechanics of pedaling.”

So even if you’re running a wider SuperBoost rear hub, you needn’t be pedalling like a cowboy, or having to settle for cheaper components. We know that Pivot bikes, the early champion of SuperBoost Plus is a regular Shimano collaborator, so there will be some happiness to hear that (though it was probably Pivot’s suggestion in the first place…)

Flat Mount XTR, XT, SLX and, er, why?

Yes, it’s very nice, but, er, eh?

And then we come to the oddest release announced today. Shimano is offering XTR, XT and SLX level brakes in a flat-mount style. Flat mount is used in the road world and its been adopted as the universal way of fitting disc brakes to delicate road bikes. As all the hardware is in the brake and its bracket, there’s no need for (strippable…) threads in the frame and the bike frame can be made lighter.

Given that Shimano already serves the road world with Dura Ace, Ultegra, 105 and now GRX flat mount brakes, we’re not really sure where this has come from. Especially as no mountain bike manufacturer that we know of is currently making flat-mount frames. Perhaps Shimano knows something that we don’t (which is often the case) and perhaps the mountain bike race world is suddenly about to adopt flat mount brakes. Or maybe someone just ticked the wrong box on a spreadsheet?

Deore Microspline

Microspline! Lets you run that 10-51T cassette…

In other news, Deore will get its own Microspline wheels and hubs. That’s something we can definitely see a use for…

As for the flat mount XTR? We’re sure that Shimano has the answer somewhere…


Comments (12)

    Whyte use flat mount on mtb frames, don’t they?

    Canyon Lux features flat mount out back.

    Cannondale, Saracen and Genesis have all used flat mount too.

    You also haven’t mentioned that the hubs pictured run on cartridge bearings – pretty big change for Shimano and one that’s likely to be welcome – especially when you see the price.

    https://www.peterverdone.com/brexit-brakeset/

    Peter Verdone thinks so as well, He’s annoying a fuck, but is usually worth listening to

    For an insight into flat mount mtb it’s worthwhile checking out USPTO Application # 20180265153: Bicycle suspension tube and bicycle suspension fork by Shimano Inc.

    https://p.vitalmtb.com/photos/forums/2018/10/09/6785/s1200_Screen_Shot_2018_10_09_at_4.17.11_PM.jpg

    I’ll go with your spreadsheet theory!

    Nick c. Thanks for peter Verdone link. That site is a cornucopia.

    “there’s no need for (strippable…) threads in the frame and the bike frame can be made lighter.”

    That turned out well for press fit BB.

    “what is very helpful for me as a designer is how tiny they are…”
    Designer < User
    (or at least that's the way it should be)

    The close bolt spacing is what makes flat mount such a pain to adjust. That and the fact that the bolt heads are facing away from you and not visible when the bike's in the stand. The bike industry is full of well-intentioned but poorly-considered changes that makes life more difficult and expensive for consumers.

    Then again, a local shop owner recently told me that Di2 was the biggest gift Shimano had given him in ages as it's too complicated for consumers to shop for online.

    I only find the close bolt spacing a pain on bikes with inappropriate cable routing which pulls the calliper under hose/cable tension. Otherwise fine and super clean.

    To be fair, you rarely see a stripped bottom bracket threads…

    Hmmm, Microspline Deore Hub and the fact that CRC/Wiggle are now listing a Deore M6100 12speed group makes me suspect that Shimano are about to make a concerted attempt to nudge OEMs away from NX/SX drivetrains on their budget focussed bikes and back towards good old Shimano.

    Flat mount being offered in MTB group lines isn’t really a shocker, it’s just a minor change to the finishing on existing (DA/Ultegra/105) calliper bodies innit. But really the question is whether that’s been asked for by the big manufacturers or is this shimano trying to influence the industry back towards a single calliper standard now in the form of Flat mount?

    It sort of lands us back in ~2006 doesn’t it. We were all just dandy with ‘IS’ and we had Post mount and then gradually nobody made IS callipers anymore because Post mount could fit IS frames/forks with adaptors, frame builders could (and a handful still do) still make and sell IS mount frames, but most migrated to PM. Brake manufacturer’s lives were made relatively simple as they now only needed to make one type of calliper. And now the exact same exercise is going to be repeated but with Post mount phased out and Flat mount replacing it. The new standard will of course be backwards compatible for a long while, and the old type of calliper will gradually fade from memory, except of course every so often you’ll need an adaptor…

    IS was fine, PM was also fine, FM will be fine…
    But it is another cheeky little swizz by the two big S’s to try and keep punters flipping those expensive toys in for new ones.

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