Fabio Fabbri (left) and his brother Cristiano.
Fabio Fabbri (left) and his brother Cristiano.

 

So when you want to really max out a smallframe to 300cc and you need an engine casing for it, where do you turn? In the case of cylinder-builder Egig, you get in touch with Fabbri Racing from the Italian hill-town of Sogliano.

 

While Fabio and Cristiano’s premises are small and the brand not so well known outside Italy, their product lines are massive. Prepare for a tour of smallframe Vespa heaven…

 

Fabio at the start of his 180 project back in 2014
Fabio at the start of his 180 project back in 2014

 

The hills are alive with the sound of 2-strokes

 

I’ve been following Fabbri’s work for over a decade. In the past he specialised in tuning, crank-building and a host of smallframe-specific upgrades such as fork, mudguard and brake conversions.

 

Since my last visit he’s added 200 more product lines, almost all of which are aimed at making Vespas go faster.

 

SLUK likes that…

 

This Fabbri weld-in section is perfect for adapting Piaggio automatic forks to the smallframe Vespa chassis
This Fabbri weld-in section is perfect for adapting Piaggio automatic forks to the smallframe Vespa chassis

 

Problem-solving mindset

 

Fabio’s thought process is relatively straightforward. He examines the Vespa for problems and produces innovative solutions to fix them.

 

This way of thinking lead Fabio to produce parts such a weld-on top fork stems to convert Vespa ET4 forks to fit smallframes. With Vespa automatic front ends in abundance, this is a simple solution to fit a hydraulic front disc brake to smallframe Vespas.

 

What’s that you say, there isn’t a front mudguard to fit? Well Fabbri dealt with that too…

 

 

A 3D print of Fabbri’s forthcoming CR-MX 300cc engine casing for Vespa Smallframe
A 3D print of Fabbri’s forthcoming CR-MX 300cc engine casing for Vespa Smallframe

 

The Fabbri CR Casing

 

Fabio has been working long enough with rival engine casing designs to know their weak points and how to improve on them.

 

The latest project is a highly-adaptable smallframe engine casing that can be taken to 300cc using a 62mm stroke crank and a 79mm piston. Or a touch bigger if you are mental.

 

Crankcase reed inlet is cast into the design. As standard, the casing is closed but the racing version can be opened for crankcase reed-valve inlet
Crankcase reed inlet is cast into the design. As standard, the casing is closed but the racing version can be opened for crankcase reed-valve inlet

 

The Fabbri’s casing incorporates the following features:

 

  • Option to accept reed-inlet cylinders, or to open the case for a rear-facing crankcase reed using a TM kart reedblock.
  • Dimension of the crankshaft is the same as for the Quattrini engine casing. Fabbri has been making crankshafts for a long time for the Quattrini engine casings and could see no advantage in reinventing the wheel – he’s made a lot of Quattrini cranks so it made sense to use the same size.
The Fabbri casing will accept up to 62mm stroke cranks
The Fabbri casing will accept up to 62mm stroke cranks

 

There are 3 versions of the casing planned:

 

  • CR-V with standard Piaggio Vespa stud layout
  • CR-E with external studs for Quattrini M200 cylinders or Fabbri 180 cylinder
  • CR-MX for the 300 barrels in collaboration with Egig
The layshaft needle roller bearing is lubricated by a tiny oil reservoir in the casting
The layshaft needle roller bearing is lubricated by a tiny oil reservoir in the casting

 

Other features include:

 

  • The design includes enough metal in the mould that it is possible to use crankshafts 3mm bigger in diameter each side
  • The casing is available to accept either the standard 4-speed gearboxes or wider 5-speed boxes with only a small modification
  • The layshaft has a hole in the middle to send oil to lubricate the running surfaces of the loose gears
  • Rear suspension bolt position moved 10mm to the rear to help with exhaust routing
  • Flywheel cover face is 3mm higher so the cover doesn’t touch the fan. Fabio also plans to make a dedicated flywheel cover
  • Fastening is with Allen screws. The lowest fit from the wheel side to prevent grounding problems when racing
The gear cluster is extractable from the flywheel side. This was important to give internal clearance for larger diameter crankshafts
The gear cluster is extractable from the flywheel side. This was important to give internal clearance for larger diameter crankshafts
The gear selector shaft, which often wears and leaks on smallframes, instead runs on a bearing with a proper oil seal
The gear selector shaft, which often wears and leaks on smallframes, instead runs on a bearing with a proper oil seal

Coming up in part 2 tomorrow…

 

More about Fabbri’s water-cooled GP CZ1 casing, cranks, 5-speed gearboxes, clutches, 180cc 42bhp cylinder kits and much more.

SLUK Shop – would you like us to stock selected Fabbri products in the UK?

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