Myrons Mopeds

Contents: 1. Engines
Contents: 2. Mopeds

 

 

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1. 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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2. 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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This entry was posted on Wednesday, December 9th, 2020 at 7:43 am and is filed under Derbi Models. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.