Shaltac Wasn't there a time when the 2 strokes were experimental tempermental beasts that were heavy and didn't perform said:Dayum. Who dug this one up, Bill?? :rotfl:
Gonna have to fire up the way-back-machine for this one. :laugh:
Shaltac.
When the 2 strokes first came out they were not very impressive. Materials for pistons, bearings, seals, rods, etc, etc, were substandard compared to what we have today. The chances of finishing a race on one without seizing a piston or fouling a plug was slim to none. You had to ride with one finger on the clutch lever so it didn't pitch you off when it seized. They were very hard to ride since they didn't have power valves to control the torque so, they were either 'off the pipe' or 'on the pipe'. Nothing in between. It was like toggle switch horsepower, not a smooth powerband. The ignition systems were not very good and didn't produce a hot enough spark to keep the plugs from fouling. That along with the lack of good 2 stroke oils. Most everyone used Blendzol, a bean oil that smelled like you were running fuel and made your eyes burn. With the expansion chambers they were very loud and during a race you would pass many of them while their riders were kicking, kicking, trying to start them. Sound familliar???
About the only thing they had going for them was they were lighter. Of course you made up for that by having to carry a pocket full of spark plugs and a plug wrench. Most everyone thought they were only a fad. Probably won't be around for long. ;)
Well, thanks to technology and the advancement of materials, the two stroke has come into its own. High silicon pistons, special coatings for cylinders, power valves, electronic ignition systems, chrome moly, magnesium, titanium, blah, blah, :blah: They are now, state-of-the-art race bikes.
Four strokes are undergoing the same transition. By using lighter materials, better materials and modern electronics, the 4 strokes are now very close to the 2 strokes as far as the way they handle and the weight. Much of this technology has been around for many years. The difference is in the materials now available to us. The rotary cam valve has been around since the early 70's. There was a bike called a Zimmerman that used two hollow shafts that rotated and had the carburetors attached to the end of the shafts. This bike put out tremendous horsepower and reved to the moon. It was very successful in So California desert racing. The main drawback was the frame kept breaking and the bottom end could not hold up to the high rpms that the engine was capable of.
Most of the technology that we think of as new, has been around for many, many years. Monoshocks go back to the 20's. The difference today is the materials that are available.
It's funny how much advancement in technology we have seen just since this thread was first posted. I purchased a WR400 and thought it was the best motorcycle I had ever owned. Trail rode it and raced it and did pretty well on it. At least until the CRF 450's came out. The CRF's were so much faster and better than my WR, I couldn't believe it. Having won races on the WR, I couldn't even keep the CRF's in sight the following year.
Back in the day we took 450 lb street bikes and stripped them down, machined everything and ground every extra bit of metal away and made 370 lb racers out of them. Today you can walk into your local dealer and walk out with a bike that is very competitive. A lot of people complain about having to check their valves and maintain their bikes but, back then we literally had to build our racers from scratch.
I know what Pete is talking about in regard to the old thumpers torque. Having ridden and raced Triumphs for many years and owned and trail ridden XR's, I like the torque that the old long rod thumpers had. And yes, I even raced a Tigger cub on shorttrack. Still own several Triumph twins. And although that type of torque works very good on trail, it doesn't cut it on a track. Especially a mx track. For that reason I keep my XR for trail and have a CRF450 for racing.
But that was then and this is now. What we are seeing today is the resurrection of the four stroke. This is just the beginning, the best is yet to come. Everyone complains about the cost's of the new bikes, the electronics, the complexity. But that is what it takes to stay up with technology. We have some fantastic machines available to us today. Most all are very good. Two stroke, four stroke, red one's, blue one's, yellow one's, green one's, orange one's. Pick a color and go ride.
Oh, and btw Bill. I know where there are a couple of tigger cubs and they still run. :yikes:
Ol'89r