Three race bike choices, what's yours?

[Tim754]

Rules: must have been or be realistically available, not "factory race team specials" ie Joe Blogs or you or me could have bought one from the manufacturer or a dealership.

Open class -   Sonic 500     (2nd choice but I think I am get into factory racing specials area ,any Clews CCM BSA derivative)
250cc/450cc-  1974 Ossa Phantom      Just visually sublime.   (2nd choice Big bore kitted  Honda 73/74 XL350, only because been there, done that love hate relationship.)
125cc -  Suzuki TM125  Easy to maintain and ride, reliable low stress fun.        (2nd choice Yamaha MX125 - as for the little Zook!

[Iain Cameron]

Open 1st choice 76 yz400 tractor power ,2nd Maico 501 just because .
250   1st DT1 pre 70 because Im strange , 2nd, same as Tim  the  Phantom sooo cool
125   1st  76 yz125x   2nd 73 125 cr because I wanted one in 73 .
Iain

[firko]

I'll go with two distinct eras....the 7"x4" suspension travel bikes and another trio for the 78-90 era........
Early
500.....  Cheney 650 Triumph or '74 Maico 400 (for different reasons and different classes)
250.....  OSSA Phantom or Rickman Montesa VR (The best two pre 75 250's in my opinion)
125.....  Yamaha YZ125 A or '74 Honda CR125 (the Honda because it's the best ever 125 and the Yamaha which could have been with an extra gear)
Late
500 ...'81 Maico 490 or  86-87 Honda CR500 (the Open class Kings) close third spot to the 83 XC 500 Husky....great bike that only just misses the cut.
250.... Yamaha YZ250 H or Honda CR250 RZ (The Yamaha because it's so good, the Honda because it looks so good.
125.... Kawasaki KX125 late 80's (not sure of the year, possibly '89...I raced it at a club day and it's the only 125 I ever felt genuinely comfortable racing. I didn't want to give it back to the owner.   

[Rusty]

Based on what you have to compete against under local and most other rules it would have to be

TM125 Suzuki
TM250 Suzuki
CZ400 Falta Replica

Given slightly altered rules

RM125S
250 Pursang MK10
CZ400 Falta Replica

[Rossvickicampbell]

pre 75 - YZ360B
pre 78 - RM370B
Evo/pre 85 - not yet sure?

So more era interested than capacities - find the 360 so much better than a 250 and waaaaaaay too big for a 125.

[Slakewell]

77KTM 400/77 GP Husky
77 KTM 250 nothing else is close
78 A4 125 Because I just like it.