Big Fun

Wheelies are the best trick ever, no debate.The Big Fun may not guarantee sick wheelies, but it’s definitely a step in the right direction.

Call it a hardcore hardtail, or maybe an enduro hardtail even. Call it a big trail bike, or the perfect weekend warrior rig… all we know is that the Big Fun is the perfect hardtail rig for big pedals and big trails.

We call the Big Fun an “agressive trail” bike, not because it’s aggressive like, its mean or anything, but because this bike just keeps coming back for more. We ride the Big Fun on our local trails, but also on the sometimes mind-boggling technical Czech trails behind Dresden, but also in Sweden or Italy at the big-kid bike parks of Europe. This is our take on the trifecta known simply as “LLS”. Long. Low. Slack. We built this model around a proven geometry that’s ready to take on any trail you can throw at it, and then some. Build your bike with a 140mm fork for a solid trail rig, or mount a 160mm fork and push yourself to the limit. Big hardtails like this are truly so much fun!

The Big Fun borrows a ton of tech from our still-top-secret full suspension trail-duro bike, like a huge ZS44/ZS56 headtube, and custom drawn tubing for all the durability with none of the trail chatter.

All of this, built by hand in Saxony!

Trail Ready Geometry

Big trails, little trails. Tall trails, short trails. We here at Sour love all trails… except hiking trails, those aren’t for bikes, but rather, hikes.

The Big Fun has big geometry, all of the float, none of the bloat. With its mega-oversized headtube, long-low-slack “LLS” geometry, and patented hardtail rear end, the Big Fun is kind of just down for whatever type of trail riding you want to do!

We made the Big Fun enduro-ish ready because we knew there would be a few of you out there that would take this bike on a few enduro stages, but drop the travel down to 140mm and leave the downhill casing tires at home, and you have a well rounded big-ger trail bike geared up for long days in the mountains. With it supremely efficient pedaling platform, long alpine days are really no trouble at all!

Gussets, Post-mount, External Cables, and a Yoke

We made the Big Fun for long days, big days, small jumps, and huge ones too. All this equates to a bike that’s probably going to need some service more often that not. Mountain biking is hard no your equipement, so thankfully the Big Fun isn’t hard on your mechanic!

External cabling might not be the most fashionable thing in the world, but it does mean you can replace any and all cabling without tearing apart a headset with 20 moving parts! In fact, the only service that requires you to tear apart your headset is, well, a headset service. Magic!

Additionally, we’ve got this frame all gussetted up, yoke’d out, and double butted, so really the only thing you should be worried about breaking is a spoke… and maybe your wrist… but as magic as the Big Fun is, we can’t help you on that one!

Shop the Big Fun in our online store!



All Sour Bicycles frames are made by hand, one-by-one, in our own facility in Saxony, just outside of Dresden. We use custom tubing designed and drawn for our frames, it’s a multi-butted heat-treated CrMo steel that’s ready to stand the test of time. All our steel is produced from a partially recycled product in Germany and drawn by one of the worlds leading production facilities in Taiwan, the beating heart of the worlds bicycle production.

Our dropouts are designed in-house in Dresden and have a replaceable derailleur hanger.

The seat clamp is designed in-house and is integrated into the frame. Should it ever fail, the frame can be professionally modified to use a traditional clamp, if repair of the original clamp is not possible. We have never seen one fail.

By the numbers:

Headtube: ZS44/ZS56 tapered headtube
Bottom bracket: 73mm BSA
Rear spacing: 148x12mm Boost thru axle
Seatpost: 31.6 mm (dropper post ready)
Brake standard: IS2000 (ISO, more info here)
Fork travel: 140 – 160mm travel
Wheel Size: 29″
Tire size: up to 29×2.6”
Tubing: Custom drawn, multiple butted, partly heat treated SOUR CrMo (we love steel)

Bonus facts and features:

Two water bottle mounts
External cable routing on the downtube for easy service
Stealth dropper post routing
31.6mm seatpost diameter for maximum dropper compatibility

Maximum chainring size: 38t round or 36t oval

Fork Options

Marzzochi Z1 150mm, black

Fox 36, 29″, 150mm, Grip, 3 POS-ADJ, 44mm Offset, black

Dropper Posts:

Bike Yoke Revive 31.6mm 125/160/185mm


Bike Yoke Triggy, 22.2mm

Fork Options

Marzzochi Bomber Z1

Fox 36

  • FIT GRIP damper and FLOAT air spring
  • Floating Axle, 44mm Offset
  • More information here (link to fork blog post)

Dropper Options

Bike Yoke Revive, 31.6mm

  • Available in 125/160/185/214mm
  • Available in any color, as long as it’s black

More information about dropper posts, click here! (blogpost about dropper compat.)

Dropper Lever:

Bike Yoke Triggy

  • Left hand for 1x drivetrain, 22.2mm

Below are the frame and fork weights for each size of the Sour Pasta Party. These weight include powdercoating, but please keep in mind that your chose powdercoat may be heavier than the average coating we use. Fades, gradients, and metallic colours can weigh more than single solid colour. If you are interested the final weight, please get in touch. Weights are averaged over three frames per size. We apply an inside wax coating before shipping the frame to your door that will add additional weight.

Big Fun S = 2760g +/- 100g

Big Fun M = 2810g +/- 100g

Big Fun L = 2870g +/- 100g

Big Fun XL = 2970g +/- 100g

*All weights averaged with 3 frames per size (±50g frame, ±20g fork)

Included with your frame

Included with your Big Fun frame or frameset is all the grommets and small parts to run any cabling you wish and a derailleur hanger. You get a rear thru-axle of course, and if you’re ordering a frameset, you get a front axle with your fork as well. Headsets are only included if you add one to your order.