Orbea Oiz XC bike built MTB race-ready at just 8.85kg / 19.5lb by Brujula weight weenies

The Orbea Oiz cross-country bike is already lightweight, but the weight weenies at Brujula Bike couldn’t resist pushing the carbon XC bike further to a complete bike weight with pedals and a bottle cage under 9kg. Orbea & Brujula admit they put a lot of exotic ultralight carbon components into the final build, but feel confident these are all race-ready mods. In fact, much of those superlight components are ones we’re used to spotting on pro bikes racing the UCI XC MTB World Cups, which also happen to kick off this weekend…

Orbea x Brujula 8.85kg Oiz XC super bike

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, custom build

c. Orbea, all photos by Brujulabike

Orbea’s Oiz full-suspension XC race mountain bike is already known for being light with its latest 1350g OMX carbon frame, and its lightweight short-travel 100mm complete bike builds weigh as little as 10kg complete with full XTR and carbon DT wheels. But that wasn’t enough for Brujulabike. Although they say, “it wasn’t enough to reduce weight at any price. It had to be completely reliable for racing and with components available on the market. The result is this spectacular full suspension MTB under 9 kg.

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, complete

They know you can build a sub 8kg XC bike if you are willing to sacrifice reliability, comfort, or even stratospheric prices. But Brujula wanted their Orbea Oiz XC race bike to be ready to rip!

Custom weight weenie build details

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, frameset workshop

Right on Orbea’s claims, this size medium Oiz OMX frameset with its carbon rocker link and inline-mounted Fox Float DPS Factory shock weighed 1740g in the lightest transparent blue paint over raw carbon. Brujula paired that to a 1418g Fox 32 Float Step Cast Factory fork, for 100mm of travel front & rear.

That’s pretty much where stock kit ended.

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, Bike Ahead Biturbo RS wheels

The most obvious upgrade are the 1376g Bike Ahead Biturbo RS monocoque 6-spoke carbon wheels, that are really light while being stiff, World Cup-proven & still 27mm wide internal (even though we’ve seen several  ~1kg XC wheels, even earlier from Bike Ahead). Topped off with Pirelli’s Scorpion XC RC Lite 2.2″ XC tires with no protections (although I’d prefer the 2.4″ version that’s just 90g heavier a piece with ProWall sidewall protection).

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, Darimo ultralight carbon cockpit components

But probably just as much weight is shed in the ultralight hand-laid carbon Darimo 93g T1 Loop seatpost with Dyneema rope saddle rail clamp, 62g stem & 108g flat handlebar. Top that with a 70g full-carbon Saevid saddle, some Orbea foam grips to keep the cockpit light, a 224g pair of Exustar pedals, and Alpitude’s silly light Superleggero carbon loop bottle cage.

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, Hopp Carbon SRAM XX1 AXS Eagle

Brujula even shed some weight off the SRAM XX1 Eagle AXS drivetrain with Hopp Carbon link plates & a Kogel Kolossos cage for the rear derailleur, plus the ultralight, ultra-machined Ukrainian Garbaruk cassette.

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, Hope XCR

And braking got a light upgrade with new Hope XCR stoppers, Ashima rotors & Kogel ti rotor bolts.

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, dropping in

Detailed Brujula weight breakdown of the Orbea Oiz project bike:

  • Frame: Orbea Oiz OMX size M,  1740g (including rear shock)
  • Rear shock: Fox Float DPS Factory i-line 100mm with remote (included above)
  • Fork: Fox 32 Float SC Factory 100 FIT4 QR15x110 with remote, 1418g
  • Wheels: Bike Ahead Biturbo RS 27mm internal, 637g front & 736g rear
  • Tires: Pirelli Scorpion XC RC Lite Team Edition 29×2.2″, 604g each
  • Brakes: Hope XCR, 195g each
  • Rotors: Ashima ai2 160mm 6-bolt, 73g each
  • Bar: Darimo MTB Handlebar 740mm no rise, 108g
  • Headset: Acros Alloy 1.125-1.5″ Integrated
  • Stem: Darimo IX2 MTB 80mm -6º, 62g
  • Grips: Orbea foam, 44g
  • Seatpost: Darimo T1 Loop 31.6, 93g
  • Seatpost clamp: Darimo Sub4, 4g
  • Saddle: Saevid Alien Short, 70g
  • Bottom bracket: Kogel BB92-Dub with ceramic bearings, 56g
  • Cranks: SRAM XX1 with 34T chainring, 426g (including 10g Kogel alloy pre-loader)
  • Chain: SRAM Eagle Rainbow, 263g (full-length)
  • Derailleur: SRAM XX1 Eagle AXS, 375g (before mods)
  • Derailleur linkage plates: Hopp Carbon
  • Shifter: SRAM XX1 Eagle AXS, 87g
  • Derailleur cage: Kogel Kolossos 14/19T alloy cage with ceramic bearings, 97g
  • Cassette: Garbaruk 10-50T, 337g
  • Bolts: Kogel Titanium  Disc Brake Kit, 8g
  • Valves: Damoff Aluminum 48mm, 12g pair
  • Sealant: Damoff tubeless tire sealant
  • Pedals: Exustar MTB EPM215TI, 224g pair
  • Bottle cage: Alpitude Superleggero, 10g

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, actual weight 8.85kg 19.5lb

Total weight: 8.85kg / 19.5lb (with pedals)

Orbea Oiz OMX sub-9kg XC super bike, 8850g mountain bike by Brujula-Bike, riding


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6 months ago

Nice job! Fun mix of the boutique (wheels and the Darimo stuff) and off-the-shelf (XX1 cranks).

6 months ago

Interesting choice to not go with all the lightest stuff possible.

6 months ago

Those Ashima rotors are a big nope for me. Rather have the grams and properly functional brakes!

6 months ago
Reply to  Cryogenii

I have one on my 2017 Orbea Occam. I does stop but modulation felt poor.

bill morris
22 days ago
Reply to  Cryogenii

I agree. There are places to save weight here without sacrificing braking power. BTW, I built up a budget xc lightweight project using a Lightcarbon.com 911 full sus frame with XTR and XT components and Lightcarbon graphene/carbon DT Swiss wheels along with cheap carbon off amazon.com, spent about $4600 and ended up with a 10.02kg bike including pedals. I plan to upgrade to a bad 10-52t cassette and shave another 130 grams off fromthe XT cassette. That will bring my $4600 build to about 9.89kg. Not bad for less than $4600 USD. And yes, its durable.This 8.85 build costs many thousands more I’m sure. I’ve had my build for 6 months now and raced it several times podiuming every outing. I’m 65 kilos and it works just fine for me.

6 months ago

Mine is lighter 🙂

6 months ago
Reply to  Ubo

yes show us then!

6 months ago
Reply to  Bill

Hi Bill, you can follow the link in my reply or by click to my name 😉


6 months ago
Reply to  Ubo

Yes clearly lighter and using a telescopic seatpost !!!

Bre Rue
Bre Rue
6 months ago
Reply to  Ubo

Mine’s the same weight as yours, except I have 120mm of travel on my 2022 MyO Oiz… The frame with full high vis paint was 1720g in a size small. It has an XX1 AXS drivetrain, Extralite bar and stem, AXS 100mm dropper, Thunder Burt tires, Magura brakes and lots of Hopp and other lightweight parts!
Although it’s 10.45kg ready to actually ride on a daily basis. This includes a chain breaker, complete multi tool, tire lever, tubeless repair kit, 2 tubes, 3 Co2, inflator, garmin 2.4/2.6 Maxxis tires and such. 😉

So much fun!

6 months ago
Reply to  Bre Rue

This is quite amazing with your description despite the use of thunder burd (these tyres are just enough resistant for gravel use), excepted if you don’t have a 120mm travel fork.
Don’t hesitate to make a full description of your bike on light-bikes.fr