Myrons Mopeds

Contents: 1. Derbi
Contents: 2. Engines
Contents: 3. Mopeds
Contents: 4. Parts

 

 

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1. Derbi

The name Derbi is from Derivats de Bicicletes (derivatives of bicycles).

From Wikipedia:  Derbi’s origins began with a little bicycle workshop in the village of Mollet, Spain near Barcelona, founded in 1922 by Simeó Rabasa i Singla. The focus remained the repair and hire of bicycles until May 1944 when Rabasa formed a limited liability company named Bicicletas Rabasa with the aim of moving into manufacturing bicycles. The venture proved very successful and in 1946, supported by its profits, work began on a motorized version. More moped than motorcycle, this first model, the 48cc SRS included plunger rear suspension, and a motorcycle type gas tank and exhaust system. The SRS proved so successful it prompted a change in the company’s direction, and on November 7, 1950, the company changed its name to Nacional Motor SA. Just prior to this, at that summer’s Barcelona Trade Fair, the company unveiled its first real motorcycle, the Derbi 250.

Derbi successfully competed in Grand Prix motorcycle racing, winning 50cc world championships in 1969, 1970 and 1972. When the 50cc class was increased to an 80cc displacement in 1984, Derbi would claim four consecutive world championships between 1986 and 1989, before the class was discontinued in Grand Prix competition. The firm also experienced racing success in 125cc Grand Prix competitions, winning world championships in 1971, 1972, 1988, 2008 and 2010. The Derbi RSA 125 earned 405 points in the constructor’s championship in the 125cc class. The 405 points in 2010 are second only to Aprilia which earned 410 points in 2007.

Unlike Ossa, Bultaco, and Montesa, Derbi successfully met the challenges that followed the Spanish transition to democracy and Spain’s entry into the European Community. Simeó Rabasa i Singla died in 1988 but the company remained independent until 2001, when it was bought out by the Piaggio group.

 

Derbi parts on 1970’s mopeds were mostly made in Spain. The Arbeo carburetor is a re-make of an Italian Dellorto. The Walker speedometer is a remake of a German VDO. The Motoplat magneto is made in Spain. Everything else is made in Spain by Derbi, except the lighting equipment is made in Italy by CEV Pagani. The reason was Spain’s high import tariffs and socialist economy. On late 80’s models there were more non-Spanish parts. The controls were Italian-made by Domino, and the magneto was Italian CEV. Gradually Spain’s trade practices became more like the rest of Europe.  

Derbi lights: European models had Rinder headlights, square with angled sides, like the gold 1978 SLE on the right. US models had round CEV headlights because they were DOT approved. Euro versions had smaller tail lights and no brake light, while for-sale-in-US bikes had larger CEV 9417.2 tail lights that shine to the sides with brake light and side reflectors. 

Nunca debera pedalear: “Never had to pedal” was the slogan in this Spanish ad. The bottom says “vane summit 3492 m (11,350 ft) the highest road in Europe”. Derbi was always setting records. In 1980 A Derbi SLE went around the world in 76 days. Derbi mopeds also crossed the Sahara and won world-class 24-hour competitions. The Derbi Variant was proven to be the world’s best moped in performance and capability.

 

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2. Engines

1976-85 Derbi moped engines (for sale in the USA) came in three speed versions:
30mph (2.0hp) 12mm xxx no restrictor,  1 – 1mm variator limiting washer (gas mileage 117 mpg)
25mph (1.5hp)  10mm intake restrictor,  1 – 4mm variator limiting washer (gas mileage 130 mpg)
20mph (1.0hp)  10mm intake restrictor,  2 – 4mm variator limiting washers

1985-89 Derbi moped engines (for sale in the USA) came in one speed version:
30mph (2.0hp) 10mm intake restrictor,  1 mm variator limiting washer
43mph actual when de-restricted!

 

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3. Mopeds

 

nr is non-reed , pr is pyramid reed, fr is flat reed engine

year  model   colors eng rims

1976 Variant SL xx ♥ nr 17 17
1976 Variant TT xt ♥ nr 17 17

1977 Variant SL xx ♥ nr 17 17
1977 Variant TT xt ♥ nr 17 17

SL and TT had 2.50-17 tires and 19T, 30T sprockets.

Derbi is the most heavy-duty moped, with a gross vehicle weight rating (GVWR) of 450 lbs.
The SL was 123 lbs, and SLE was 125 lbs, so the rider (with passenger and cargo) can weigh 325 lbs.

1978 Variant SL X   ♥ nr 17 17
1978 Variant SLE  ♥♥ nr 17 17
1978 Variant TT   ♥♥ nr 17 17
1978 Laguna xxxx  ♥ nr 17 17
1978 C5 Diablo xx  ♥ nr 21 18

SLE and Laguna also had 5-star wheels, 2.50-17 tires and 19T, 30T sprockets. C5 had 2.50-21 and 2.75-18 tires, and 20T, 42T sprockets.

 

1979 Variant SL  ♥♥♥ nr 17 17
1979 Variant SLE  ♥♥ nr 17 17
1979 Variant TT   ♥♥ nr 17 17
1979 Laguna xxx    ♥ nr 17 17 
1979 C5 Diablo xx  ♥ nr 21 18

 

1980 Variant SL  ♥♥♥ nr 17 17
1980 Variant SLE  ♥♥ nr 17 17
1980 Variant TT x   ♥ nr 17 17
1980 Laguna xxx    ♥ nr 17 17
1980 C5 Diablo xx  ♥ nr 21 18

 

 

 

 

 

 

1981 Variant SL x ♥ nr 17 17
1981 Variant SLE ♥♥ nr 17 17
1981 Variant TT x  ♥ nr 17 17
1981 Laguna xxxx  ♥ nr 17 17
1981 C5 Diablo xx  ♥ nr 21 18

 

 

1982 Variant SL xx   ♥ nr 17 17
1982 Variant SLE   ♥♥ nr 17 17
1982 Variant TT x   ♥ nr 17 17
1982 Laguna xxxx  ♥ nr 17 17
1982 C5 Diablo xx  ♥ nr 21 18

 

 

 

 

 

1983 Variant SL x ♥◊ pr 16 16
1983 Variant SLE  ♥♥ pr 17 17
1983 Variant SLE-E ♥ pr 17 17
1983 Sport Laguna ♥ pr 17 17
1983 RD50 Diablo  ♥ pr 21 18
1983 Scoot 50  xxx  ♥ pr 10 10
1983 Scoot 50-E  ♥♥♥ pr 10 10
1983 Scoot 80-E  ♥♥♥ pr 10 10

The movie “War Games” came out in May 1983. It featured a 1983 Derbi SL white. The flyer says “60th anniversary 1922-1982”.

 

 

The 1983-86’s have these subtle improvements:
crankcase 3-petal pyramid reed valve for more torque
90 degree throttle cable, not “straight out” (longer wire)
black aluminum brake levers not black plastic
front sprocket sticks out more, nut hits earlier left cover
the cast aluminum swing arm was upgraded to box steel
the center panel choke button is 2 inches farther back

 

 

The 1983 SL had 2.50-16 tires and 20T, 30T sprockets. RD50 had 20T, 42T sprockets, same tires as C5, 2.50-21 and 2.75-18.

The 1983 SLE-E (electric) had electric start. The sticker on the side of the frame was “Variant Botton Rojo”

There never was a parts catalog made for the 1983-1986 Derbi mopeds. There were only addenda or updates to the 1976-1982 parts catalog, in the form of loose sheets of paper.

1984 Variant SL    ♥◊ pr 16 16
1984 Variant SLE  ♥♥ pr 17 17
’84 Variant SLE-E  ♥♥ pr 17 17
’84 Variant SLE-C    ♥ pr 17 17
1984 RD50 xxxxxx  ♥ pr 21 18
1984 Scoot 50-E  ♥◊♥ pr 10 10
1984 Scoot 80-E  ♥◊♥ pr 10 10

 

The Scoot 50 and Scoot 80 had a de-restricted pyramid-reed moped engine, but without pedals. Notice how much thicker the front exhaust header pipe is. These scooters went 40 to 55 mph. 

The SLE-C (commercial) had a solo seat to allow a cargo rack. It was for business, like pizza delivery.  

 

 

 

 

 

 

 

 

 

1985 Variant SL x-♥◊ pr 16 16
1985 Variant SL xx  ◊ fr 16 16
’85 Variant SLE-X  ♥♥ fr 17 17
1985 RD50 xxxxxx  ♥ pr 21 18

The new SL flat-reed had 13T, 33T sprockets.
The new SLE flat-reed had 13T, 35T and 17″ 7-star wheels.

 

 

 

1986 Variant SL xx  ◊ fr 16 16
’86 Variant SLE-X ♥♥ fr 17 17
1986 DS50 Scooter ◊ fr 10 10
1986 RD50 xxxxx   ♥ pr 21 18

The new DS50 had electric start, 3.00-10 tires, and 16? front, 33 or 34T rear sprockets.

 

The 1986-89’s have these subtle improvements:
Many things are different that appear to be the same.
Flat 2-petal case reed valve, “Scanimet” all aluminum cylinder
Reverse rotation for better induction, so it has an extra shaft
Both crankshaft nuts are left thread, old ones are both right
Domino controls with integrated CEV switches, different cables
CEV square speedo and square headlight with hi/lo, not round
New frame – engine swings with rear wheel, takes bumps better
Improved variator with wider range, more torque
Voltage regulator and stronger magneto, brighter lights
Top speed 43 mph! with intake & variator restrictors removed.

Variant Sport had 2.75-16 tires, 13T, 33T sprockets.

 

 

1987 Variant Sport ◊♥ fr 16 16
1987 DS50 Scooter ◊♥ fr 10 10
1987 RD50 xxxxxx   ♥ pr 21 18

 

1988 Variant Sport ♥♥ fr 16 16
1988 DS50 Scooter ♥♥ fr 10 10

 

1989 Variant Sport ♥♥ fr 16 16
1989 DS50 Scooter ♥♥ fr 10 10

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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4. Parts

Most Derbi parts are in the Parts by Type section. This area is for Derbi-only items. It’s under construction…

This entry was posted on Saturday, August 18th, 2012 at 8:25 am and is filed under Derbi Parts. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.