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​Hot Rod Cranks


Evoloved from the original Grove designed 2 piece mountain crank from 1978, the new Hot Rods continue to offer the pinnacle of design and function, efficiently turning your energy into forward momentum. So what makes the Hot Rod so special? Well, besides the carefully handcrafted attention that goes into each Groovy product, it's really the design that takes this piece beyond expectations...

Tobias Hot Rod.jpg 


Material details

Each Hot rod starts out with 4130 aircraft chromolly that is swaged to an oval shape,machined to achieve maximum surface area coverage at component interfaces for strength, and is welded together with strict attention to tolerances. Once fabricated, the piece is then heat treated to relieve internal stresses and attain ultimate strength and durability. A quick run through a plating bath then protects the substrate as well as providing a durable/smooth finish on the spindle for reduced bearing interface friction.


Design highlights

The bottom bracket spindle mates to the crank arm using a tri-coidal Polygon, a 3 lobe shape that provides almost 100% surface contact with no opportunity to strip, slip, or wallow out like a splined end. A close tolerance design allows for the crank to be installed without any preload, allowing for longer bearing life as there is no side load present. Two 5mm bolts gently secure the arm in place. At 24mm, the spindle diameter is compatible with any "Shimano standard" outboard bearing.



The pedal receiver spans the bredth of the arm, but is machined out behind the depth of the threads to reduce weight. A vent hole allows for the evaporation of internal condensation and facilitates the introduction of "frame saver" to insure long life.



The spider interface relies on 5 points of contact for strength and alignment; a highly toleranced machined spindle hole, 3 fixing bolts that mate to the faced crank interface, and a crank arm buck to resist torsional stress. The unique design allows for the use of a spider for chain ring use, or a dedicated chainwheel for single ring operations. Custom sprokets available by special order. 






Crank arm length - available in 175mm or 180mm

Spindle diameter - 24mm, compatible with "shimano standard" outboard bearings

BB sizing - available for standard 68mm, 73mm, or the new 100mm standard

Spiders - available in all current bcd's, double and triple ring, 4 and 5 arm configurations

Q factor - standard Hot Rod, 188mm, Rohloff version, 189.5mm

Weight - 720grams with spider

Colors - standard matte black ceramic coated, custom colors for upcharge, available unpainted to authorized frame builders


Steel - $450 plus 20.00 shipping by Insured USPS Priority mail domestically, 45.00 for international

​​​Titanium - $​800 plus 20.00 shipping by Insured USPS Priority mail domestically, 45.00 for international

Available ONLY on complete builds.