Rich Rohrich

[fastwes]

Please excuse my spelling...WRITING tooo fast.

 

[Rich Rohrich]

Originally posted by fastwes
Rich, What the hell do you think a piston top is??? A golf ball??? just tighten the squish up if you want turbulance!

Wes - We have 97mm+ bores and those annoying valve cutouts mucking up the whole thing so we'll take all the help we can get :)

 

[EricGorr]

Thanks for the comments Wes. If we didn't have a sense of humor we'd be mental cases. And if we didn't have DRN we'd be like the unibombers of the motorcycle industry, scribbling notes and manifestos on the sides of new motorcycle crates.

Now don't get Rich started on the Von Karman effect. A little known fact about Rich; he tracks hail storms on Doppler radar and races over to them in his Dodge truck in an effort to get the entire surface pummeled by hail stones so as to produce a total golf ball effect for that ellusive extra 5mph..

Speaking of unique piston configurations, I'll be posting a photo of SFO's new piston. He's actually modified his 97mm YZF piston to invent a 3-stroke by making transfer ports in the valve reliefs.

Considering that we rode down a parallel path with you guys at Boyesen regarding issues like mass centralization and discovering the polar moment of a dirt bike, perhaps we should start a thread on ideas that never made it to print or the market. Any chance Eyvind would cut loose with some photos or concepts? I had a rare chance to interview Hans Tilkens' apprentice in Belgium a decade ago and he had some wacky stuff on the same subject. And I'll bet if we prod the guys from Down Under, we could dig up some real doozies to talk about!

 

[RM_guy]

That would be great if you guys could dig up some of the more wacky and/or unique ideas that have sprouted up over the years. One of the rags did something like that a few years ago but there wasn’t nearly enough detail to quench my desires.

 

[nephron]

RJ was riding a factory Yamaha with the big high tank and the radiator mounted to the triple clamp. Kenny was riding the factory Honda. We talked about weight bias and riding and such. RJ brought up an interesting point that top heavy bikes were easy to throw down in a turn and it seemed that the greater the displacement the more beneficial it was for the bike to be top heavy. The next year RJ was signed to Honda and Yamaha started shifting down the mass of their bikes except the 490 which retained the “high and wide” look.

Now that's some cool stuff. :)
Is there any association between that statement, persistent Yamaha philosophy, and the top-heavy-ish 426 vs. the skirtless piston/low center of gravity CRF? :think

Neat stuff.

 

[EricGorr]

Funny enough Bob Oliver was RJ's mechanic back then. After RJ went to Honda Bob joined the YZ development team with Ed Schiedler and has been instrumental in the development of the YZs for 20 years.
Regarding the high CG on big bikes, Rich and I speculated once that perhaps it has something to do with the crankshaft inertia. Speculating that the greater inertia will make the bike more difficult to lean over in a turn and that the higher CG helps off-set that effect. I remember when Kawasaki Japan tried to fit the KX500 engine into the KX250 chassis for Dave Thorpe and he complained that he couldn't corner the bike as well as a standard KX500. They went roundy-round about that problem all year and finally blamed it on Dave saying he was over the hill. I think that the team manager just couldn't admit that they had an engineering problem. But if you went into a motocross orientated pub in England there were always old motorcycle blokes pondering about the handling problems of that new fangled bike over several pints of room-temperature ale. Because of course DT was "The People's Champion" and could do no wrong. Personally I believe they were right and that bike ended Dave's career 5 years too soon.
Maybe somebody ought to do some investigation into the relation of crankshaft inertia and the bike's CG. I just talked to Doug from Service Honda today and he had some wise cracks about Rich's freshly lowered CRF. I reminded him that Rich could throw that bike into the back of his pick-up truck with 1 hand :p

 

[SFO]

Originally posted by EricGorr

Now don't get Rich started on the Von Karman effect. A little known fact about Rich; he tracks hail storms on Doppler radar and races over to them in his Dodge truck in an effort to get the entire surface pummeled by hail stones so as to produce a total golf ball effect for that ellusive extra 5mph..

Speaking of unique piston configurations, I'll be posting a photo of SFO's new piston. He's actually modified his 97mm YZF piston to invent a 3-stroke by making transfer ports in the valve reliefs.

Golf balls and three strokes...
what happened to moderater integrity?
Next we will be talking about F O U R W H E E L E R S

 

[MXN4FUN]

Will those dimples cure my slice? I always seem to crash to the right. Or is distance the main goal ?

 

[marcusgunby]

Eric did you know dave thorpe is riding again in the british 4 stroke championships?he is on a 426 and is doing really well.He is still very fit.

 

[Rich Rohrich]

Originally posted by marcusgunby
Eric did you know dave thorpe is riding again in the british 4 stroke championships?he is on a 426 and is doing really well.He is still very fit.

It would be fun to see Yamaha include him in the next YROC race. I'll bet DT could give those boys a run for their money. :D

 

[Rich Rohrich]

Originally posted by VintageDirt
Now that's what I like to hear. :confused:

I was fortunate enough to meet Super Hunky and his personna in real life mirrored his writing. Just a really fun down to earth guy. It was great to meet one of my heros and NOT be disappointed.

 

[kingriz1]

Very cool.

So that was schelgor. You guys should or probably have started playing with ideas again.

You never know when that idea will hit with everything else in the right place.

 

[CC_RIDER]

This thread deserves to be archived! So much great information, not just about the bikes and engineering, but also the people. After all, if it weren't for the people who engineer, build, and ride these bikes, what good would they be. "It ain't about the bike"

Definitely the most entertaining/informative thread I've read in a while.

Thanks guys!

 

[Battered Sav]

Another vote for the archives, excellent thread.
D'oh, checked the archives, and there it is, thanks, and sorry.

 

[BSWIFT]

Save this one, Okie. :)

 

[bscottr]

An AWESOME read.......a damn good basis for a new book.


Thanks Guys :thumb:


Okie,
Gotta agree...save it, this should be required reading for new members. :)

 

[techman]

I have a vague recollection of the bike with no tank jumping. Wonder if I still have the mag somewhere. On the topic of rotational inertia and crank size, I'd bet no one except a few computer jockey eng's in the big R&D depts have ever got any solid numbers to discuss. For those with a need to know and the time and gumption to do it, one can calculate such things via oscillation and pendulum type experiments (combined with a bit of CofG balancing measurements). It would lend a whole new dimension to talking about how "light and flickable" a bike was. There would be a de-rating or encumbrance added to the results by adding flywheel effects from the crank and wheels, maybe even gearsets to be complete. Interesting point: if the crank was forward rotating like the wheels, the whole bike would like to turn better one way than the other due to the gyro effects during leaning and turning the bars (did I get those vectors right?). I couldn't say offhand if those secondary effects would have enough size to be noticeable. Also, when the suspension is compressed, the whole bike gets smaller, reducing the polar inertia ....

I can picture the test rig, but doing it ... yeah, right, in my next lifetime.

Very enjoyable hearing the stories from the trenches. I'll be sure to listen well when words of wisdom are spoken, knowing the depth of background. :-) :worship: :-)

 

[Tony Eeds]

Okie - I had dinner with Patman and he told me to look this thread up. This is more than archive material. I knew this site was filled with really smart and dedicated people, little did I know how smart.

Tony

 

[kingriz1]

I knew this site was filled with really smart and dedicated people, little did I know how smart.

Awww cut it out! Your making me blush ;)

 

[Patman]

This thread needed some sun light.

 

[Casper250]

I though it was locked up in the technical articles dungeon.

 

[bclapham]

This thread needed some sun light.

thanks pat- yes a great thread- watching Dave Thorpe storm to a world championship on saturday morning TV is what got me into motorcycles.

 

[JPIVEY]

Holly cow, Rich, I suspected you had roots somewhere, but had no idea it was anything like that, that was the coolest thing I've read in a long time.


Thanks for bringing this back to the top,

 

[Kav]

Now that's a good read

 

[Timr]

Thanks for the comments Wes. If we didn't have a sense of humor we'd be mental cases. And if we didn't have DRN we'd be like the unibombers of the motorcycle industry, scribbling notes and manifestos on the sides of new motorcycle crates.

Now don't get Rich started on the Von Karman effect. A little known fact about Rich; he tracks hail storms on Doppler radar and races over to them in his Dodge truck in an effort to get the entire surface pummeled by hail stones so as to produce a total golf ball effect for that ellusive extra 5mph..

So you're saying that you're not mental cases? :rotfl: That's still open for debate. I think the release of your motorcycle manifesto would've made for some good news; probably followed by a nationally televised low speed chase.

Speaking of the golf ball aero effect, didn't NIKE make Lance Armstrong a one off speed suite for a time trial in the Tour a couple of years ago where the whole surface was dimpled like a golf ball? They claimed it was worth 30 - 50 seconds over the length of the Individual TT.

I think I saw Rich trying to bid on this suit on E B A Y. We'll see if he wears it at this years DW. (Um, Rich and Lance don't have exactly the same build. :nener: )