Pre-95.

[Nathan S]

Geoff, Great minds think alike - and apparently so do your's and mine.  

I've been thinking about the technological advances made in mainstream production bikes since 1970, how quickly they were adopted by other manufacturers/how long did it take before they made a worthwhile difference, and whether they were really a performance improvement (rather than a marketing gimmick)...
I've ignored anything that was tried and dropped (like boost bottles).
(And please don't turn this into a train-spotting exercise, arguing over whether the 1974 KX450 was mainstream or not)

In rough chronological order:

1970~74.
Reed valves.
6-speed gearbox (for 125s).
Plastic fuel tanks.
Single shock.

1975~79.
More than 4" travel rear.
More than 7" travel front.
Bigger diameter forks (goes hand-in-hand with longer forks).
 
1980~84.
Twin leader front drum brakes.
Plated cylinders (ignoring the earlier chrome bores).
Linkage rear suspension.
Water cooling.
Exhaust power valves.
Front disc brakes.
Safety seats.
Case reed intakes.

1985~90.
Rear discs.
USD forks.
Multi-stage power-valves.

1990~94.
Perimeter frames.
Long-stroke 2-stroke motors.


1995+.
Aluminium frames.
The modern 4-stroke.
Flat seats/foward handlebars.
Hydraulic clutches.
3D ignitions.


The interesting thing is that very few of those were clear improvements in their first year - and many of them were actually steps backwards for a while. Most of the remainder only made very minor improvements to performance.
Also worth noting that not every bike in the era got the improvement straight away, and often only a small number had it (eg: Only two bikes had an alloy frame in 1999).

[AjayVMX]

[shoey]

[AjayVMX]

I've seen babies look like that - it usually means they're busting out a big one... 

[shoey]

[vmx42]

I've seen babies look like that - it usually means they're busting out a big one... 

And I know for a fact that you never hung around to enjoy the consequences. 

All that was heard was the sound of slamming doors and the car starting… 

[worms]

best thread in ages

love ya work Shoey and Ajay

[LWC82PE]

Ok ive seen it mentioned a few times now, what is a 3D ignition?

Suzuki had had case reed induction back in the mid 70's.

[AjayVMX]

I've seen babies look like that - it usually means they're busting out a big one... 

And I know for a fact that you never hung around to enjoy the consequences. 

All that was heard was the sound of slamming doors and the car starting… 

[shoey]

Best do the honorable thing , and do a runner from the little guy when he's about to bust a move rather than "



Throw up a cat or something

[shoey]

And if the wife is the same



Good chance the kid's going to go ferral ,have some issues later in life

[Rossvickicampbell]

if one of the main concerns here is numbers on the grid - or lack thereof - why bother with cut off dates - why not just team up with a modern club and run the classess you have enough for on the day - if not enough fit in with the vets.  I am sure that will keep the VMX movement alive.

[suzuki43]

[clutchslip]

Posted by: LWC82PE

Ok ive seen it mentioned a few times now, what is a 3D ignition?

Well a good question always demands a full and detailed response, and the way this thread is heading, it might not be a bad thing...

3D ignition is based on the concept of maps, just like the ones popularized by the Greeks and Dutch, and the ones you use when you get out of the shed and try and navigate your way to the campsite at a vmx meet that's new to you. Geographical maps come in the 2D 'political kind' - where different states are shown in different colours for example - and the 3D kind, the ones that show 'relief' or contour lines representing altitude, as well as longitude and latitude - your school, if funded adequately, may well have had one of those pop out plastic versions showing all the hills and valleys and stuff.

Let's apply this to ignition. An ignition distributor often uses little bobweights, thrown out according to engine speed by centrifugal force, to recreate the elementary 2D map envisaged by its designer; you've probably seen these maps, or because its only 2D, 'graphs', plotting ignition advance against engine revs, ie matching up one variable with a constant. These systems are inherently difficult to adjust as they are based on a combination of Greek and Victorian values and technology, neither of which are well known for their flexibility. These same concepts were applied to fuelling, in mechanical fuel injection systems. In the eternal quest for performance enhancement, clever types began to think about applying 'solid sate' electronic conepts and eventually micro-processor technology to these weakspots. In geography, 3D contour maps had been around a very long time by this point so it was pretty obvious that these clever people were eventually going to try and produce 3D ignition and fuelling maps, combining on the same map as revs and advance, other more exotic concepts including engine load, nitrous injection or actually, anything you desire, including the volume of your in-car entertainment system. This step into the third dimension was a brave one, and remains difficult for most of us to comprehend, let alone install on our own vee-hikkles. Thankfully, or maybe not, DIY 3D is now a possibility, thanks to the kind people at www.megasquirt.info etc. At this point you may well be thinking, 'but how is this relevant to all the guys here who've got smoke belching two-strokes, the very essence of technology reduced to its most base and awesome form?'. Well trust me, in addition to those loons willing to pay silly dollars for their period 'Martek MotoTek' ignition (me included), I'm sure that if you trawl the interweb for long enough you will find someone who has indeed installed a 3D map controlling not only sparks but the Yamalube injection on their early 70s crosser, but my guess is that this bike would not even be eligible in pre-95.

[shoey]

Religion and motorcycles , that's an interesting mix