The Sour Crumble. A tasty bit of trail bike, made even tastier. Modern XC? Trail bike? The one for anything? The one for everything?! Yes.

The updated Crumble has received all the right tweaks in all the right places. A little bit here, a little bit there, all sorts of little details and updates all to time-warp our favourite trail bike up to the right here and right now.

The Crumble’s new longer reach paired with the not-too-steep head angle combines downhill prowess with quick steering characteristics and low speed fun. Still, there’s nothing too fancy and experimental here, just a tried and true classic… like a slice of sweet crumble pie.

All of this, handmade!

Please note:

  • All frames are made in Germany in our workshop now.
  • Production will happen on a quarterly basis with delivery times being between 8 and 12 weeks.



Handmade Sour Bicycles CrMo frame featuring heat treated, multi-butted tubing that’s ED-Coated for rust-proofing.

Our dropouts and 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.

By The Numbers:

Headtube: 44mm

Bottom bracket: 73mm BSA threaded

Rear spacing: 148x12mm Boost thru axle

Seatpost: 31.6mm diameter

Brake standard: PM160 disc brake standard (max. 180mm, more info here)

Fork travel: 120mm – 140mm

Wheel size: size small 27.5″ only. M-XL 29“ only

Tire clearance: for up to 2.5“

Bonus facts and features:

New 66.5° headtube angle (with a 531mm fork)

Internal cable routing

Stealth dropper cable routing


FOX 34 Performance Elite 130mm black

2022, 34mm Cast, 29″, 130mm, FIT4, 3 POS-ADJ, 15QR x 110mm, 44mm Offset 

Marzocchi Z2 130mm black

2021, 34mm cast, 29″, 130mm, Rail Sweep-Adj, 15QR x 110mm, 44mm offset 

Dropper Posts:

Bike Yoke Revive 31,6mm 125/160/185 mm black


Bike Yoke Triggy left for 1x drivetrain, 22.2 mm

Frameweights incl. powdercoating and small parts

Crumble S = 2660g +/- 50g

Crumble M = 2710g +/- 50g

Crumble L = 2770g +/- 50g

Crumble XL = 2870g +/- 50g

Fox 34 Performance Elite = 1750 g +/- 50g 29″

Marzzochi Z2 = 2075 g +/- 50g 29″

Bike Yoke Revive 31,6mm 125mm = 475g

Bike Yoke Revive 31,6mm 160mm = 535g

Bike Yoke Revive 31,6mm 185mm = 575g

All weights in grams g.
All weights averaged with 3 frames per size.

Delivery items

Frame: Frame, Derailleur hanger and axle

Frameset: Frameparts + Fork, front axle and Acros headset