First Japanese Dirt Bikes?

[jerry]

Firko was there works rider i 58' J

[VMX60]

The RT1MX was supplied from the Yamaha factory as a motocross only model with the 21in front wheel and marketed as  purpose built MX weapon

And Ken George Yamaha WA sold a shit load of them

Your DT2MX way later in the 70s

Cheers

[JohnnyO]

The RT1MX was supplied from the Yamaha factory as a motocross only model with the 21in front wheel and marketed as  purpose built MX weapon

And Ken George Yamaha WA sold a shit load of them

Your DT2MX way later in the 70s

Cheers

VMX60 i think what Firko said below is correct

Yamaha.The DT1MX and RT1MX were released in 1970 but thery were basically kitted trail bikes so the first proper Yamaha motocrosser was the DT2MX in 1972.

[the stig]

     Well i am stretching the memory bucket here but
     i thought Yamaha's 1st prody scramble bike was a
     250 twin more or less the RD250 road bike motor .
     and it was called just that 250 Scrambler..
      I think someone called Don that worked for Milledge
      brothers rode it at Christmas Hills First time out it
      had nothing below 4000 revs it was made for the
      American Type of Racing but a failure as a Scramble
      Bike..
     
       The Stig..
     

[the stig]

   Come to think of it .it may of only been a 175  or 200 twin
   
   As the Japanese only made most of there motors after 175cc
 
   200cc 400cc  600cc back then..
   
   The Stig..

[firko]

The RT1MX was supplied from the Yamaha factory as a motocross only model with the 21in front wheel and marketed as  purpose built MX weapon

I know what you're saying but the DT1MX and RT1MX were based on the existing enduro version while the DT2MX was a new from the ground up design with no enduro connections. The DT2 Enduro was based on tye old DT1 and a totally different frame to that of the DT2MX. Hardly any parts flowed over from the Enduro to the MX.
I had a genuine yellow stripe RT1MX back in the day and my mate had a GYT kitted RT1 Enduro and there was little difference, bar his red stripe and my chrome bore.

[firko]

by: the stig
IWell i am stretching the memory bucket here but
     i thought Yamaha's 1st prody scramble bike was a
     250 twin more or less the RD250 road bike motor .

I doubt that many (if any) of these Yamaha's were ever sold or whether they could be considered a proper production motocrosser but they're a unique bit of kit with a great story.


http://www.classicyams.com/race-bikes/early-factory-racers/yamaha-yd-racer-catalina-gp.html

[farmpro]

The first Japanese bikes I remember here in the states in order were the Suzuki RH67,Kawasaki F21M and Bridgestone 100 & 175 Racers.All were pretty limited production but did come out of the crate ready to race.Kawasaki F81M & G31M came a little later also in small quantities.Next the DT & RT2MX's which appear to be the first really mass produced racers.

Bill Davis            Texas Vintage Racing Club

[Tim754]

Hodaka had their Ace 100 MX (AKA Super Rat) about for public purchase in 69.

[the stig]

    Yamaha made there first Scramble bike in 1963 it was called the
    AS1 250 scrambler made for there domestic market they bought
    a few to Australia in the 60s but could not sell them.
     If you got a spare couple of Hours Google in( Early Yamaha Scramble
     motor cycles ) there are some good links on this subject .
     Yes a Variant of the DT250 MX250 was the there first World Scramble
      bike thanks to the Yanks..

        The Stig