1973 Vespa Sprint Veloce

1973 Vespa Sprint Veloce

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Sandy’s first scooter and longest relationship. With numerous engine set ups over the years Sandy now has a Nitro-fed monster! With special thanks to Trevor Howe (Prospect 13) who taught me to persist and pursue my dreams and Malcolm (formerly head mechanic of Scooter Emporium London) for imparting his technical engineering skills, to not only build this scooter but realize my dreams in building thousands of scooters for my customers.

PRIZES:

  • Best Street Racer (Auto Italia 2006)
  • Best Vespa (National Scooter Rally Dubbo 2006)
  • Best Overall Scooter (National Scooter Rally Dubbo 2006)
  • Best Vespa (National Scooter Rally Port Macquarie 2007)
  • Best Custom (National Scooter Rally Port Macquarie 2007)
  • Best Vespa (Motorini 2008)
  • Best Racer (National Scooter Rally Stanthorpe 2009)

As published in TW SCOOTER MAGAZINE on 26/05/2005
Words & photography by Jeremy Bowdler

This 1973 Series 2 Vespa Sprint Veloce is good for 13.9s on the dragstrip, pumps out 21kW at the rear wheel, cruises at 120km/h and tops out at just less than the Imperial ton at 153km/h. So how did a cheap runabout commuter turn feral?

Sandy bought the “pile of nothing” second-hand in London £600 and it was a pile of nothing. It was also his first scooter and the beginning not only of a long-term affair but a long-term career.

“In the first month I had the bike fully rebuilt to standard and resprayed by hand (by me). I soon realised I didn’t have enough power so I started asking a lot of guys round the UK scene the best way of tuning. For me, the central thing in building a Vespa is always the engine,” Sandy continues. “Getting the engine right and getting it in there from the start, making it 100 per cent reliable and then building the bike around it is the way to go.

“This is literally engine number five. I’ve got a couple of engines spare lying around the place that produce a fair amount of horsepower but are still working and still very reliable but not like this one. This is putting out peak horsepower for a normally aspirated carburated Vespa 150 engine.”

The work started with a 12-volt conversion and a lot of advice from the UK scooter tuners about porting and polishing barrels, reed valves, cranks, etc and it evolved into Sandy’s current occupation.

“A lot of my parts are sourced from Germany just because Vespa tuning is huge over there, so a lot of my bike comes from SIP and Worb 5 in Germany and, in the UK, Alan at Beedspeed UK, Taffspeed Tuning, Malcolm at Scooter Emporium and Patch at Scooter Surgery have all given me insight into tuning scooter barrels and pistons and stuff like reed valving to get maximum horsepower without sacrificing reliability or rideability.”

The Sprint Veloce has an MRB four-petal reed valve and runs a 30mm Dell’Orto flatslide carb and fuel pump which make sure the engine doesn’t suffer from fuel starvation (a problem in some circumstances thanks to the original gravity fuel feed)

“The carb gives me a lot of low down horsepower where I need it and by adding the Dell’Orto fuel pump I’ve eliminated any chance of the fuel starvation especially with an engine that wants to breathe as hard as this engine does, ” adds Sandy.

The pipe is from SIP and is tuned for low-down torque to add driveability to the power the scooter pumps out. The head was modified by the German Suzuki Race Team to take a centrally mounted spark plug and to offer a compression ration (around 10.0:1) that will not only take normal fuel, but also a 50/50 Avgas blend.

The Malossi 172cc barrel and piston have been matched, ported and polished to within an inch of their life by Beedspeed UK, but without taking so much metal away that the tuning makes the barrel weak. A Worb 5 high quality full circle crank eliminates wobble in the big end bearing and, according to Sandy, are perfect to run in these engines.

The HP4 flywheel has been lightened, from 2700g to 1800g, so the engine spins to higher rpm and accelerates far more quickly. There’s a little sacrifice in rideability, but once the bike does hit the powerband, it flies.

The clutch is a 21-tooth unit from the Coaster model and is reinforced with a metal ring on the outside to stop any chance of the clutch basket vibrating and cracking itself loose. The clutch’s reinforced springs make it stronger than normal Vespa clutches so the clutch plates wear less, you get a very smooth change and you eliminate the need to be “a 120kg power lifter” to operate it.

Work on the chassis started with the suspension and Bitubo shocks. An SIP wide tyre kit was fitted at the back for better straight-line performance and handling. The wider tyre at the rear requires a lot of modification to the swingarm, but it makes a huge difference to the handling. It’s a 130/70 tyre, which is pretty much as big as you can go.

At the front, the suspension was lowered by an inch so the bike sits lower and Sandy gets less wheel lift. Surprisingly, the brakes are standard, with Sandy’s philosophy being drum brakes are fantastic as long as you maintain them. Keep the drums clean from dirt and grease and you’ll never have an issue.

“I then moved on to the engine, which is based on a P5 150cc engine and built it from there up. After I had perfected the engine, which took me two attempts at getting it right and tweaking it correctly, I started a full respray of the bike, sandblasted it back to the bare metal and any modifications I needed to do to the chassis or the body were done in the process.”

The fastback seat is an SIP fibreglass unit from Germany. On newer scooters it doesn’t look so good, but on the classic models it just accentuates the whole line of the bike. It’s a very reliable but very quick Vespa that still maintains the classic style of the old Vespas but has a very special, unique, racer look.”

Overall lines are one thing, but with a show scooter, it’s the special little details that set it apart. There are little LEDs that light up in the speedometer; a quick action Tommaselli grip modified for a scooter; braided lines everywhere; and chrome. “I spent a lot of money on chrome,” Sandy remembers, “which is usually against my ethic. My ethic is chrome doesn’t bring you home, while matt black always brings you back. But I thought, for a show bike that I’d do a lot of chroming on bits and parts, like forks to really set the bike off.

“I’ve been a Vespa and Lambretta mechanic for 10 years now and, as a result of that knowledge, I’ve put everything I know into this one scooter, seeing it is my first love and my biggest passion.”


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