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cool bike

3890 Views 35 Replies 8 Participants Last post by  imslow
dave from australia just ordered a tshirt and sent pics of his bike. it's a modern bike so I didn't put it on the site but it's still a cool bike. I've never heard of one before. dave says they're popular in australia and europe but were never sold in the US.

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Yep...270 degrees. 180 90 = 270. Or 360 - 90 = 270.

It fires that. Cylinders firing 90 degrees apart, then a 270 degree rotation of the crankshaft, one cylinder fires, 90 degrees later the other cylinder fires...then the crank goes around another 270 degrees and process starts over.
You can fire an engine just about any way you want, just cut the cam to match and there you go. Balancing is all handled by the fly weights on the crankshaft.
Like Harleys...they fire at 45 degrees apart I think.
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Aaron, I like your ° .... although I hear the guys in P-town LOVE your ° .'s a haxor trick....beware.

Actually the British kind of pioneered the 360° crank like the Honda uses. Don't numerous trumpet and other British twins use the same setup? Pistons move up and down at the same time but fire on alternating revolutions.

Missing a shift used to be the death knell of my engines. I was running the x4 camshaft with a head built by, well I won't say. Every missed shift was bent valves. Then I went to the x20 cam, wasn't quite so bad, every other missed shift was a bent valve.

Then I had the head done up proper. I've missed shifts and just buried the 12k tach..had to be 14k rpm. Everytime I would cringe, just knowing when I back off the throttle it would die and not run below 4 or 5k rpm. But to my surprise it takes the abuse just fine. Despite the fact that the valves are larger and heavier! Just goes to show you what proper spring rates and heights and bronze guides will do.

This Mike Rich guy does not fuck around. If you want genuine, pro race quality mods made then he's the guy to see. No guessing, nothing half assed or cobbed together, he does the kind of work you see on AMA superbikes. Computer flow bench, all kinds of engine simulation work, matching valve rates to rpm, valve weight and cam profile. He even flows the head to a specific camshaft profile. You gotta send him the whole head, assembled, preferrably with intakes and carbs attached. No just sending a bare head and have someone hog it out based on some kind of wives tale voodoo. Mike will break all the rules if the flow bench says that's what you have to do.

He told me one bit of very valuable information about the 175's vert heads. It's not the ports that are the problem, it's the valves. Mildly ported heads will flow about as much as the valves can pass. You gotta go with bigger valves if you want the big power.

What I can't believe is that so far the rockers and cam lobes seem to be holding up great. I have no doubt that if one wanted to throw the dollars at one of these engines you could see a usable 14k rpm. It would require Ti valves and new seats to keep the spring pressures down. But it's doable, and would sound great.

A project for another year I guess.


PS. I know...a lot of talk to respond to a simple statement about a missed shift..but there you go..the wonder of modern medicine.
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All the CB 125s (SS twin), 160s, 175s, and 200s were 360 degree.

The symptoms of a bent valve vary depending on how badly it's bent. If you just tweak it a little it won't run below like 4,000 rpm. Tweak it a little more and it won't run below 7,000 rpm. Tweak a little more and it won't run at all. Tweak it real bad and it blows right the fuck up.

As for skill and power. A skillful person can adapt to inferior equipment because of his skill. A person lacking in skill will never develope the necessary skill with a piece of crap, he'll just learn how to operate a piece of crap. I'll put it like this, if you fly fast airplanes and you want to learn how one feels at mach+ speeds you will never find out if you are flying a piece of crap that won't do mach+ speeds. So, develope all the skill you want, when you get into a plane that does mach+ speeds you will now be learning how to fly a fast plane AND learning a new way to fly. When you see an experienced rider beat other people while riding a piece of crap, he's utilizing a skill set he obtained by riding fast bikes. You can't learn to go fast on a bike that won't go fast. You can't have good corner speed on a bike that handles poorly. It works the same way as any TOOL does. If you use better tools, most likely the quality or your work will improve.
I think many of you underestimate your own skill. To blow my own horn for a second, I can keep up with the top two guys in 200gp and the top four in 250 gp....why? It's not my skill, which is average, it's my bike that is fast. So as my skills improve I am already acclimated to a bike one which I can fully utilize those skills.
A huge part of going fast is KNOWING you can go fast. Someone like Zack can take a piece of crap and beat people on fast bikes because he's been on very fast bikes...he KNOWS that HE can go fast. He can push the piece of crap to the limit. If you have a piece of crap that will only go 35mph through turn three, you will never know what if feels like to go through at 45mph. If you have a bike that will only do 75mph you will never know what it feels like to enter turn one at 95mph, so you are not learning the skill set that you will need to go fast, you are only learning the skill set needed to ride the bike you are on.
Skill can adapt to poor equipment, but only within limits. A bike needs to be setup with the basic requirments to be competitive in a class if you ever expect to find out if YOU are competitive in a class.

Scott, you've taken racing school right? The most important lesson they teach is to "look where you want to go"...and don't look where you don't want to go. I acclimated myself to NHIS by riding a 130hp RC51 there that would hit 140mph by turn one, and probably 110 into three. When you operate a machine in those realms and then get on a 20hp bike you go into it with a feel for what is POSSIBLE. You know that YOU can go through a corner at a given speed, then it's just a matter of making YOU AND THE BIKE with 20hp do it as fast as possible. It's like this, I'm going through turn one on my 200, instead of saying to myself MAYBE I can go through here a little faster the next time, I can say to myself I KNOW I can go way faster because I've done it before on a different bike, now I just have to DO IT on this bike.
And don't say "hey, that's different, you did it on a modern bike" because that would be admitting that machinery DOES make a difference. Sure your bike will go faster....but do you know if YOU can go faster? I already know I can, simple because I did it on a bike that would go faster. It's all a confidence thing (well a lot of it is). I'd rather go into a hot dog eating contest knowing I've eaten 30 of them, and knowing that I only have to eat 20 of them to win this one.

Not sure about sound checks. I know last time them said I was over...screw em, I've got a fully closed supertrapp system installed. I find it hard to believe my little 200 is too loud, doesn't seem possible.

And Scott, I'm not implying that your bike is a piece of crap :) I was just using and extreme to make a point. And the head work is about $800 bucks. Not cheap, but not a huge amount compared to the overall price of building a race bike.

My new can't go fast on a slow bike, but you can go slow on a fast bike.
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quote: Johnny B.,

Are you implying that Talabach builds a piece of shit slow bike??

What in heavens name are you talking about?

If you mean the Zack reference, I was talking about the race where he came in second in 350 gp on a junkyard Honda.
Can I bump my 200 into WERA 500gp?

I gotta start working on a 240cc engine.

One of these days I'm going to build a 240cc engine that I can swap out between races. This little bike would be a hoot with 30hp.
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