From Sour’s first beginnings, their retro-modern Bad Granny mountain bike klunker had been a favorite of MTB project builds. A rigid steel singlespeed mountain bike with an extra reinforcing tube in the front triangle. It’s a blast to ride, but a hard sell vs. a proper trail hardtail. Hard to justify keeping in their regular line-up, too. So, Sour decided to go limited edition. Ultra-limited. Just 10 bikes will be made and go on sale today!
Sour Bad Granny steel-everything limited edition MTB klunker
Yeah, Sour decided to go all in on building their klunker mountain bike into something unique. The result is this ultra limited edition Bad Granny with a rusty steel patina, a matching custom-made Brainfart steel handlebar with integrated dropper remote, and matching tubular steel Cyber cranks with an ActoFive chainring. All custom bits made in Dresden, Germany.
Brainfart Industries powers the whole thing – a kind of hare-brained development side of Sour’s frame-brazer Flori. This is a guy who brazes all the custom details for Sour bikes for a living, and in his spare time made an extra-wide integrated 3-piece gravel cockpit by cutting a dropbar in half and clamping the scraps back together in a steel stem+mid-section bar combo.
Really custom bits
The Bad Granny frame & fork themselves are already the definition of rad. But Sour wanted to make it even cooler for this Raw limited edition. So you get the same custom steel 22.2mm handlebars that Flori built for himself.
That Brainfart Industries CrMo Handlebar features a dropper post remote lever directly brazed-on. The bars get 6° of upsweep and 16° of backsweep. And they are size-specific 820mm wide for S/M, 820mm for M/L, and 840mm for L/XL.
Sour says, “We can’t promise that every bar might be a little bit different and every remote with a different shape. Who knows!”
On top of that, the Bad Granny includes a raw set of Cyber Cycles steel Cyber Cranks, like we shared from Bespoked. You pick from 160, 165, or 170mm long crank arms and also get a direct mount 32T chainring machined from aluminum by ActoFive, just around the corner from Sour in Dresden.
Tech details
Sour welds the Bad Granny and its rigid fork are entirely in Germany. And there’s no hiding the work, here. Thus, built from custom-drawn & partially recycled multi-butted heat-treated chomoly steel tubing. It features a 44mm headtube for tapered or straight steerers. There’s an eccentric bottom bracket shell for a threaded 73mm BB to run singlespeed or geared with an optional derailleur hanger out back.
And a split in the stay if you want a belt drive.
The frame is Boost, with IS disc brake tabs, and an integrated clamp holding the 31.6mm seatpost in place. Cable routing is of course external, but with stealth routing for a dropper post since the custom bar integrates a steel dropper remote.
To clarify, the unicrown Bad Granny Steel fork features a tapered steerer, a 15x110mm thru-axle, and IS disc brake tabs, plus 4 eyelets per fork leg. Fork length is 470mm (100mm suspension corrected), with 50mm offset.
Max tire clearance is 27.5 x 2.4″ or 29 x 2.3″.
Sour x Brainfart x Cyber Bad Granny Raw LTD – ultra-limited availability
Sour only manage to convince Flori to build ten of these cockpits and ten of these frames. So, Sour will make just 10 of the steel-everything Sour x Brainfart x Cyber Bad Granny modern klunkers. Available only in a “raw and rusty everything” finish with an individually numbered plate on the toptube. They do get a wax framesaver coating inside, and come with a bottle of blended linseed oil to protect the outside.
“The frame, fork, cranks, and even handlebars are completely raw steel, they will rust. None of these parts will ever been sold as raw again.”
They go on sale direct from Sour today at 17:00 CET… which is essentially now.
Pricing is 2420€ for the frameset (frame, fork, cranks, handlebar), including worldwide shipping.
Pre-order one now in 1 of 3 stock sizes (S/M-L/XL), and they’ll fabricate it over the winter for you to build up into your own custom dream klunker. The pre-order window is max 2 weeks (or until the sellout in minutes), with frameset deliveries 90 days later.
Be the coolest kid on the block with the raddest commuter bike and retro trail shredder. Snap one up before they disappear.
