Lambretta Li Series I
With the advent of the new LI and TV’s, Innocenti made a radical break with their past scooter design. Indeed, there was one basic similarity between the old LD’s and the new LI in that the new scooters were still built around a metal tube frame, upon which the body panels were bolted. Other than that, the new scooters were a new design from the ground up. The basic design was so good, that the Series I Lambrettas formed the basic platform upon which all further models were based.
The Lambretta LI came in two motor displacements, 125 and 150cc. Though the motors differed between the 125 and the 150, the bodies on the two models were essentially the same. Minor differences included the markings on the speedometer and available paint schemes. The 125 LI was only available in grey, while the 150 was available in several two-tone combinations.
As mentioned above, the introduction of the LI represented a big leap from the LD. The LI was physically much larger than the LD. The cowls on the LI were very long. They were curvy with tasteful large art-deco style badges on the bottom front of the panels and aerodynamic styled levers at the back. There was a small Lambretta badge and model designation badge on the legshield. There was also an Innocenti shield in the center of the horncasting below the headlight.
Unlike on the LD, which simply had a cover, the LI headset was fully enclosed. It was built in two pieces, which could come apart for cable access. The headset housed a speedometer, kill switch, light switch, and fork lock. The speedometer was of a new large round design, and was surrounded by a raised polished bezel. The scooter model was written on the speedometer face.
On the front of the scooter, the front mudguard was totally new. On the LD and LC, the front mudguard was attached to the forks, and turned with them. On the LI, the mudguard was enlarged, and was attached to the front of the legshields, so it did not turn with the forks. As with the LD, the headlight was attached to the horncasting, and it also did not turn with the forks. The horncasting, naturally, also held the horn, which was hidden behind a grille with vertical slats.
At the rear of the scooter, there were attachment holes for accessories just above the rear taillight. A spare tire bracket, or rear rack could be easily mounted here. If a factory spare tire bracket was mounted, the spare was adorned with a round metal spare tire cover which had the Innocenti logo stamped in the center. On early models, the frame had vertical slats in this area to accommodate the air flow for the “frame breather” air filter. On later models, the slats were filled in.
Also at the rear of the frame, the taillight was of a new design. As on late model LD’s, the light housing was directly attached to the frame. On the LI, it was made larger. Several different companies manufactured the taillights for Innocenti, and the design changed slightly throughout the production run.
Both the LI 125 and 150 came standard with two single seats. They were mounted at the top of the frame with four bolt attachment points. The seats could be substituted with a single long dual saddle as well. Whereas previously the LD had a plastic screw-in gas filler cap, the LI had a hole in the frame which was covered by a metal flap. This fuel filler hole was located in between the two seats at the center of the frame.
One other notable feature of the LI was the addition of a larger glovebox inside the frame. The LD had a very small glovebox at the rear of the frame, but it was often difficult to reach, especially if a spare tire or rear luggage rack was installed. On the LI, the glovebox was physically larger in size, and was moved to the front of the frame, just before the fuel tank. The glovebox was accessed through a door on the frame, just below the seat. The door had a lockable keyed latch, with a separate key from the column lock.
The motor used on the LD and previous models was totally scrapped with the introduction of the LI. The new LI motor was changed to a much more simple design. The motor design was now built around a horizontal axis. This allowed the motor to be mounted lower in the frame, and freed up space in the frame for the larger fuel tank and glove box on the LI.
The cylinder was now mounted horizontally, as opposed to the vertical cylinder on the LD models. The shaft drive, with its complicated bevel gears was eliminated. In its place was an enclosed duplex chain drive system. A simple spring cush-gear was housed at the front of the motor on the end of the crankshaft, while the clutch, primary, and secondary gears were housed at the back of the motor. On the opposite end of the crankshaft from the cush-gear was the flywheel magneto. Perched just above the flywheel was the Del’Orto carburetor. On early models, the air intake for the carburetor fed through the main frame tube, and out through the back of the scooter. This was later simplified to a system which had a larger air intake box with a filter mounted inside. This airbox was mounted between the fuel tank and glovebox, and drew air through a small hole on the top of the frame, just below the front seat.
The kickstart on the LI was simplified, and moved to the rear of the engine. The new motor design allowed for the cases to be split along a large portion of the right side of the motor. With the right floorboard and exhaust silencer removed, this design allowed relatively easy access to the clutch and gearbox.
Speaking of the exhaust, it too was re-designed. The silencer was mounted on the right side of the motor, just below the floorboard. It was a three piece design, with a “U” shaped header pipe, silencer, and final exhaust pipe.
The lights and ignition were fed through a very simple two coil generator. One coil fed the ignition, and the other the electrical equipment. The system did not put out much power. Innocenti sourced the flywheel generators from several different companies over the production run, and some of the suppliers provided better and more reliable systems than others.
Finally, one other significant change to note was the shift from 8” wheels on all previous Lambrettas, to 10” wheels on the LI and TV. From this point forward, Innocenti would only mount the larger wheels on the Lambrettas. The new wheels were of a split-rim design and were interchangeable across all models. The front forks continued to have a trailing link system, with the springs housed inside the fork tubes. The larger wheel rims allowed the mounting of larger brakes on the new models.
The Series I LI’s are solidly constructed and well designed scooters. One downside to the solid construction is that they are quite heavy, and this affects their speed. None of these scooters could reasonably described as fast, and the 125 is positively slow. Due to their size, and poor performance, the Series I scooters are best described as cruisers for short trips, rather than something which could be driven regularly.
One other thing counting against them is that many of the body parts are very difficult to find by now. They do have many shared body panels with the later Series II, but that doesn’t help matters much in the U.S. Though the Series II LI was the biggest seller in Innocenti history, relatively few survive in this country. As far as I know, there is no aftermarket production of any body parts for the Series I or Series II LI at this time. Keep that in mind when searching for a bike. An incomplete scooter will likely lead you on a long-term search for parts.
As for the motor, the outlook is quite a bit better. The Series I shares some motor components with later models, and many parts that are not directly shared, can be replaced with a part of a newer design. This means that one can reasonably assume that you will be able to keep a running scooter on the road for years to come. It is also likely that the parts need to get an incomplete or non-running scooter going are going to be available.
These models are solidly constructed and are quite heavy. The large legshields block a fair amount of air. In combination with somewhat weak motors, these scooters pretty slow. The 125 is really too slow to drive regularly, and the 150 is only slightly better. Lighting was not a strong point, as the generator had only two coils, one for lighting and one for spark, but they are slightly better than the LD’s. Motor parts are easy to obtain, while body parts can be hard to get.
Number Produced: 47,747 125′s – 110,944 150′s
Years Produced: 1958-59
Power Output: 5.2 hp @ 5,200 rpm (125); 6.5 hp @ 5,300 rpm (150)
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