Gilera Silhouette RC600 Aero Replica

A Dakar inspired look a like


Gilera and Dakar : Being a Brianzolo (the area of Northern Italy between the 2 cities Milano and Como) means being especially very proud of one Italian brand name and its accomplishments through history: Gilera!

Unfortunately for the North American continent which never benefited for the last 40 years form the imports of such marvelous motorcycles, Gilera is a somewhat an obscure brand. For example, very few know that Gilera invented the supermotard style with their Nordwest model and opened up a new motorcycle segment market. Without going back to its successful history and relating more to the recent races, in the late 90s Gilera of Arcore participated with success with their motorcycles to the Dakar. Such bikes were built on the bi-4 600 engine platform and won the Dakar and the pharaohs rally. The latest bikes used the famous/infamous 750 engine which was also utilized in the extremely rare Bimota Gb1. Often the Gilera aficionados refer to the latest style Dakar bike as “Aero” from the word “Aereodinamica” because of its development in the wind tunnel,;some others like me call it Moby Dick because of that beautiful linear fish like shape and definitely its magnificent “presence”.

Owning the real McCoy -an ex Mandelli which raced at the Dakar 2000- was not enough to me as I could not really put my hands on the bike and build it myself. From here, my fever of building a replica using bits and pieces from the early and late Dakar bikes began….

The fever is still high and it will never die….

1990 “Moby Dick” Replica     moby




I needed a donor bike. Nothing better than a 1990 RC600 (COBRA) even though it would have been better to start with the RC600R because of its better suspension -front forks and elongated swing arm . My goal was to create a bike which could resemble at high level the racing Moby Dickgileramds10 gileramds0











My luck; can you  really call it such?”It all began when I was to able to find some bits and pieces for one of those factory bikes.

OLYMPUS DIGITAL CAMERAThis would work perfectly for my replica (at least I thought first). The parts included the back tank, the 2 front tanks, the full fairing, the seat base, the filter box, the front fender and other miscellaneous bits and pieces






The project was initiated but not completed in Italy by a motorcycle artisan.

gileramds7 Unfortunately for me, I couldn’t wait any longer for the slow progress and finally took the project over. In Italy, the custom ss collector and exhaust were built, the pegs relocation mounts, most of the main frame mods executed, the tool boxes built , and the water canister constructed, last the back tank mounting frames done.









Other parts I got with other Gileras ( eg Mandelli bike) were the 2 magnesium  hubs for the racing Gilera bikes. 

gileramds2My good friend and riding buddy Jim at M.A.P Engineering  machined the Nissin caliper mount for the front wheel. A Ducati Monster  300 MM front rotor was used on the 45 mm marzocchi forks. The extremely complicated back wheel and its adapter are is still a work in in progress.







The stainless steel exhaust with spring retainers  installed. gileramds3Today, I still fail to understand why the exhaust was made by welding small tubes together. Lot of work for nothing but look.







The air filter box is installed with fast rubber mounts handles on the top.gileramds5 This will allow the quick inspection and clean of the air filter during my desert rides. I realize it is not a Gilera factory solution, but I like it. The air filter is from the automotive market -Lancia delta Evo-…what a coincidence! This is the connection to the other beauty.serbatoisella4










This is how the bike looks like at its current stage. I first  fabricated the rubber duct that connects the air filter to the carbs. It is not the perfect solution but it is definitely a start. Later on through the help of a great Gilerista I got the real Dakar duct. I have included a pic of the 2 ducts side to side for comparison.

Pictures of the back tank and of its custom frame mounts. Such mounts have been drilled to save some weight. You may notice the space for the small battery and the hole for the gas lid

The back tank is installed. This gives me a better idea where to place the electric wiring since the bike has changed a lot from its original configuration. I had to relocate the holes on the tank brackets twice as the back tank was too high in the back.









Seat base adaptation. It flushes well with the filter housing. I have been waiting for a battery to then make the final decision and trim the seat before the upholstery work.

Regarding the instrument panel, I opted for simplicity. The pic says it all.instrnew Notice the gorgeous forged triple trees and the fully adjustable marzocchi forks. I may later on install the IMOS and the Road book. I recently got a hint for the compass used from the Factory on those bikesIMG_1704









The back wheel of the 750 Dakar bike was first installed on the bike. mozzi dakar2Unfortunately I have realized that the sprocket carrier I had was the one for the 600 Dakar bike. The two hubs are different. Darn!!!!  The diameter of the housing for the sprocket carrier is different, the 750 wheel is bigger of course. See pictures. ruota750 After 4 months I was to able to secure a 600 Dakar hub. I am currently having the new wheel laced to complete the back tire installation. Again here the great help of other gilerista who came to my rescue made this possible




Everything is for the final fit.

frontinc2………still some more minor adjustments…















The sprocket adapter plus the dakar wheel are installed. In addition, a new forged bracket has been machined to house a brand new 4 pistons caliper. The bike should stop well with a late generation Nissin 4 pistons caliper. I can now drive with a full load of gas….










Working on the front lights as I did not like the auxiliary fog lights installed previously. Brackets were built for this purpose. One light is a low beam and another the high beam. Same as the ones installed in the later Yamahas.lights








Working on the front end of the bike. Installed the 2 brackets; wired the lights, positioned a horn, and finally a led light relay for the back blinkers. The wiring diagram is pretty simple compared to other bikes. It works well. I had to install the radiator temp sensor on the custom larger radiators as the accell didn’t read the head temp sensor installed on the bike










Better view of the radiators. I exactly doubled the cooling capacity. Better safe then sorry. This means that will be heavier in the front but I don’t care as I don’t plan to race it anyway. The fans are of course SPAL, the best and are Italian like the bike. I looked for the ones who absorbed the least amperage to go easy on the electric circuit. Going back I would have installed only one fan on the left side of the bike as it is sufficient, but I like symmetry and the fans are extremely light. I still need to work on some guards but I have not decided how to design them as the basic solution of a metal grill doesn’t appeal me at a all.






There is always a time when you build a bike and you ask yourself ” Did I forget anything ?” Well, yes I did. It was the fuel pump and there weas no way that that carb could suck gasoline under its positioning level. So, I drilled a hole in the vacuum side of the cylinder manifold and installed a nipple (metric of course). I am picky about it. I would go the extra mile to ensure everything is metric on this project. The pump is temporary positioned close to the bash plate which I recently made adapting a plate from another thumper. Once I test the functionality of it, I will move it to the back of the bike. I have seen another place that I like the best. Note also the down pipes protection.


MOBY DICK is white. So why white? well….. I believe it is the only color for Moby Dick.




RC_True, Renato, Filippo, CFAS-Dakota, Dakobox, rc.rAle, Eclips, duc27, Kanaka, DakoBG, Apelle, Tizio.8020, Liba and Bubix for the, advices and encouragement  to rebuild such a beauty.

RC-True and Renato for helping me locating  parts

Jim and Frank for their work on various parts

Yasmine and Lulu for their patience in so many hours Papa’ spent in the garage


Make Model

Gilera RC 600




Liquid cooled, four stroke, single cylinder, DOHC, 4 valves


558 cc Bore x Stroke 98 x 74 mm Compression Ratio 10.5:1


2x 30mm carbs

Ignition  /  Starting

Electronic  /  electric

Max Power

53 hp @ 7800 rpm (rear tyre  45.5 hp @ 6750 rpm )

Max Torque

5.0 kg-m @ 5750 rpm

Transmission  /  Drive

5 Speed  /  chain

Front Suspension

40mm Telescopic forks, 160mm wheel travel.

Rear Suspension

Monoshock, 260mm wheel travel.

Front Brakes

Single 260mm disc 2 piston caliper

Rear Brakes

Single 220mm disc 1 piston caliper

Front Tyre

90/90 -21

Rear Tyre

130/80 -17

Dry-Weight / Wet-Weight

141 kg / 152 kg

Fuel Capacity

12 Litres

Consumption  average

15.0 km/lit

Braking 60 – 0 / 100 – 0

16.2 m / 46.3 m

Standing ¼ Mile

13.3 sec / 153.9 km/h

Top Speed

155.6 km/h






5 Responses

  1. Gilera RC 600, de Desert Pistons November 28, 2013 at 10:22 pm |
  2. Andrea Leggieri
    Andrea Leggieri February 18, 2014 at 4:16 pm | | Reply

    Ciao a tutti, sono l’organizzatore della EROICA IN MOTO (, la nuova “Woodstock” dell’enduro vintage, in programma a Giaole in Chianti dal 23 al 25 maggio, e vista la vostra passione per le enduro e le strade bianche avrei piacere di invitarvi anche sul nostro gruppo dedicato:
    LAMPSSS, Andrea

  3. davide
    davide January 5, 2017 at 1:20 am | | Reply

    Buon giorno, innanzitutto splendido sito web! Mi piacerebbe sapere se il kit riprodotto qui é reperibile e dove, grazie.

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