A PINKBIKE ORIGINAL
THE GRIM DONUT
Part 1: we went to Taiwan & made a bike from the future...
Words by Mike LevyWhat happens when a joke becomes reality?
It took tens of millions of years for the opposable thumb to show up, and only slightly less time for mountain bike geometry to get to the point where our bikes aren’t actively trying to kill us. This whole evolution thing is a long, slow process.
Just one ride on a machine from a decade ago is all it takes to realize that development hasn't been standing still—bikes these days are damn good. But it sure does seem unhurried sometimes.
Brands design bikes to sell them, shocking I know. From a business perspective there’s just not a lot of upside to taking huge risks in the geometry department. So for all their talk of "game-changing" and "revolutionary," it makes sense for many brands to design bikes to be on-trend next year rather than roll the dice on what might
be the future. Something risky may not win over customers, even if it's the future.
Yes, there are outliers, the people making wild things in their workshops, and occasionally the established brands can be adventurous, too. But, for the most part, the industry seems to be pushing the envelope forward by about, oh I don’t know, a single degree and a handful of millimeters every few years. At this rate, bikes will have their own opposable thumbs in another twenty million years... But what if we skipped the evolution part and went straight to revolution?
We've spent the last few years talking half-seriously about how we should just extrapolate where mountain bike development *might be* by pressing the fast-forward button. So what happens when a joke becomes reality and we do exactly that? We're going to find out.
Of course, bikes are really damn good these days, and steady evolution is probably in most riders' best interests... but in the name of “science” or something, it's time to take things a little too far by building a bike from the future. A very long and slack future, it turns out. Geometry from 2030
The first step was to figure out what bikes would look like in ten years, and we didn't need one of those ''engineer'' types to figure that one out. Wheel size debates and chainstay lengths come and go, but if we see “longer and slacker” in one more press kit…
And unlike developing a new suspension design, geometry doesn't cost anything.
Go back a decade and lots of bikes had head angles hovering around 69-degrees, seat angles that felt about the same, and front-end lengths best suited to small children. Yeah, things were cramped and we flipped over the bars a lot.
So to get to our geometry from the future, we just took the numbers from 2010, punched them into our 2020 digital extrapolator, and boom, we had the numbers we'll be using in 2030. Hey everyone, you're welcome.From custom carbon to catalog aluminum
The best-laid plans often go awry, but that doesn't apply here given that our plans weren't laid all that well.
The dream of letting the factories fight over who was going to manufacture our wacky design was destined to be drowned in bubble tea. Tongue-in-cheek impossible suspension design aside, the startup costs for custom carbon fiber construction would have been far, far too high. Sure, we could have pulled a Tesla and pre-sold some bikes to pay for building them, but we’re too irresponsible to have that hanging over our heads.
Instead, the idler pulley, dual-link suspension layout (High Pivot Virtual™) and carbon construction were abandoned in favor of an already-designed catalog frame—but built with our 2030 geometry. This is where Genio, a relatively small but high-end Taiwanese factory, enters the story with their 160mm-travel GF7-1-160A frame.
You can call it the Grim Donut. What have we done?
With headtube angles pushing 63° these days, we had to go all the way to 57°. Along the same misguided lines, we've got some modern bikes with seattube angles around 78°, so we added 5° to get to an 83° seattube angle.
Hey, this geometry thing really isn’t all that hard after all.
Reach ended up be decided for us. We were constrained to 500mm because we didn't want to order a bunch of custom tubes or weld two toptubes together, but that seems like a big number so it's probably correct. And then we decided to call it a small-sized frame because, despite the long reach, the super-steep seat angle means the effective toptube length is actually a hair shorter than many small bikes on the market. But in a neat trick, it’s pretty damn big when you stand up! The seat tube is just 400mm tall, too.
If wheels have gotten larger over time, they're probably going to keep getting larger, right? No doubt, which is why we originally looked into making a 29"/32" wheel size combo (sorry). All we got were blank stares and dial tones when we tried to show tire companies the future, though, so our project had to roll on a 27.5"/29" mullet setup. The small rear wheel does allow for conservative 450mm chainstays (we wouldn’t want to get too crazy, right?). Other numbers include 155mm-long children’s cranks, and a 180mm fork mated to 160mm of rear-wheel-travel.
Genio took our geometry numbers, double and triple checked with us to make sure it was actually what we wanted for some reason, and then lit the torch. Eight long weeks later a box arrived at Pinkbike HQ with the very first Grim Donut prototype inside of it.The build
We assume that by 2030 all suspension will be attached directly to our brains via Bluetooth, but for now we went with a RockShox Lyrik and Super Deluxe Coil Ultimate. SRAM won the Innovation of the Year
and I'd put money on them being the first to try implementing that brain-implanted suspension microchip, so hopefully they'll offer an upgrade kit. We did try flipping the crown around to shorten the offset, but it ended up contacting the arch and we could feel the SRAM techs' disapproving eye-rolls from miles away.
It's obvious that drivetrains will keep having fewer and fewer gears when you look at the trends since the "glory days" of 27-speed bikes, so we went ahead and chose SRAM's 8-speed eMTB drivetrain. And shrinking crank lengths made it obvious that we had to run SRAM's 155mm kids' bike crankset. It actually looks super badass. TRP eMTB brakes with chonky rotors keep the e-bike theme going, along with e*thirteen's wheels and tires. We're also sticking with the OneUp dropper post because it'll probably still be running fine in ten years, and someone
is weirdly obsessed with those weird looking Tioga saddles...
And the rest is, errrr, history.Stay tuned for part 2 - can you skip evolution? Has the Grim Donut gone too far or is it the right amount of stupid? We'll find out in the next episode.
Brian Park & Jason Lucas
Produced & Directed by
Mike Levy, Mike Kazimer,
Calvin Lin, & Yoann Barelli
Additional Footage by
Max Barron & Chris Ricci
Mike Levy & Brian Park
Special Thanks to
Genio Bikes, Taipei Cycle Show, TAITRA
Astro, A-Mega, A Pro, Waki Designs for
the Grim Donut drawings, Duncan Riffle
at SRAM, Connor Bondlow at e*Thirteen
Sam Richards at OneUp, Cody Philips,
TRP Brakes, Chris Cocalis at Pivot, The
Aava Whistler Hotel, Nick Morgan at
Corsa Cycles, Karl & Radek Burkat