Topic: Rob will be happy

[turboguzzi]

Motonline has published an article on the Japauto 750's by Alan Cathcart, cool pics (and what an hideous fairing...)

http://www.motonline.com/prove/Articolo.cfm?Codice=336144

for a bad google translation go here:

http://translate.google.it/translate?hl=en&sl=it&tl=en&u=http%3A%2F%2Fwww.motonline.com%2Fprove%2FArticolo.cfm%3FCodice%3D336144

TG

[nippon]

nice article, thanks.
If you are interested in a detailed view of my Japauto VX1000 cylinder and piston,.....
http://www.classiccyclecity.com/gallery/thumbnails.php?album=54

nippon

[voxonda]

Hey TG,

A big thanks mate. Know this article thru the Japauto Club. It is the (replica) bike of the president of the Club, Patrick Massé.
@ nippon: Nice set you have. Did you have any problems concerning fitting of the cylinderblock? The block we have here had to be adjusted to fit over the studs.

Cheers, Rob

[nippon]

Hi Rob,
until yet, i did not test it. I just made a stack for some pics. Further I have to bore the cylinder up to 70,50 mm and looking for some pistons for it.
Probably, I have to go with 71,00 mm and APE pistons. After finishing a customer bike, i will work on the Seeley/Japauto engine to get this project done.
If i run in the same problems like you have, i let you know.

Rob, please could you contact Patrick for me, I would like to order a reproduction Japauto ignition cover and it is a little bit hard to talk to him,....i do not speack french and he does not speak english. If possible, you could take the cover to Spa this year. What do you think?

Btw, a bead blasted and clear powder coated Seeley frame looks killer.

nippon

[Sam Green Racing]

I dig the gold glue it's all stuck together with, looks killer cool.

Serious, it does look good, a lot of racers back in the day never put paint on the frames to save weight, would just wipe them over with light oil, the clear powder coat gives the elusion but adds a little weight and it won't go rusty.

Sam.

[NickO]

.............................. a lot of racers back in the day never put paint on the frames to save weight, would just wipe them over with light oil, .........................

Sam.

Sam,

Correct me if I'm wrong, but I thought it was so they could see any cracks/broken brazing???

Nick

[Sam Green Racing]

It was both Nick, in some cases, just not enough time to paint.

Sam.

[turboguzzi]

It was both Nick, in some cases, just not enough time to paint.

Sam.

And on the other hand it didnt stop them from adding half - ton footpeg brackets like in that japauto.....

How much can that plate weight rob? bet its measured in kilos rather than grams.....

TG

[voxonda]

Hey TG,

The Japauto is a replica from the '73 Bol d'or winner. That bike used a oem frame. Japauto never used Seeley frames, but did use at one point Dresda frames in the beginning. Later used the PEM frames.
About the footrest bracket, it not only holds the footpeg, but also is used as a stress member since it connects the rear upper and lower engine mounts.
The Japauto's where purpose build endurance racers and had to withstand 24 hours of beating. And one have to see it in right time frame.

cheers, Rob

[nippon]

Sam, you are right. but i'm a girlie and I have powder coated it. And it is much more cheaper than a nickle job.
The bike in the  pic (Seeley mkII) gave me this inspiration, seen in Spa two years ago.

nippon

[mec]

About the footrest bracket, it not only holds the footpeg, but also is used as a stress member since it connects the rear upper and lower engine mounts.
cheers, Rob

where are the benefits? we are talking about oem frames! doesn´t make any sence to me.

mec

[turboguzzi]

About the footrest bracket, it not only holds the footpeg, but also is used as a stress member since it connects the rear upper and lower engine mounts.
cheers, Rob

where are the benefits? we are talking about oem frames! doesn´t make any sence to me.

mec

+1, cant see any meaningful flex happening between those two points.....

[voxonda]

Whether it makes sence or not fact is that more people, racing the oem 750 frame, did similar things. Look at the Patrick Bodden "Big Benly" bike. Look at the bolt seizes used to mount the engine and the drilled holes of the frame, there is room for improvement. Of course there are more ways leading to Rome! I turned bolts that fit tight in the frame and reinforce the engine mounts.

[voxonda]

Lukily there are more that like the oem frames:

Patrick improved on the Japauto 'solution' by connecting the SA-pivot bolt in there too. Of course was some 20 odd years later.

[Ricky_Racer]

Thanks for posting the article, TG! It's not easy to get new JapAuto info.

I'm surprised by two things from the JapAuto article: 1) The tested bike used a 19" front wheel, and 2) the cylinder appears to be a conventional cylinder bored to 970... I can perhaps understand the choice of the larger front wheel in an endurance race where rider comfort is more important than turn-in, but why the choice of standard cylinder?

Also surprised that, since the forks on the magazine article bike appear to have the mounts for standard front fender supports, the front forks look like 35mm Honda units, as do the triple clamps. I'm fortunate to have a NOS 38mm Marzocchi/JapAuto front end for my JapAuto build but I planned on using an 18" front rim. My front end has an oversized "rhino horn" triple. Does that indicate that it would only be correct for the '70-'71 version of the JapAuto?

BTW, neat cam cover on the JapAuto test bike! I've never seen a JapAuto cam cover! Cool.

RR

[nippon]

Didn't they start with conventional Honda cylinders in 1971 before they made 1972 or 1973 their own cylinder in order to avoid oil leakings?

[Ricky_Racer]

Thomas, from my limited resources, it appears that the cylinder may have developed for street applications. Perhaps to prevent leaks?

They were most certainly not used as late as 1975 (see photo), nor was the cylinder used on the 1972 Dresda-chassis racer. At least according to my files.

Perhaps leakage wasn't the main concern of the factory race builders?  Info is hard to come by so... I dunno.   But it's interesting.  RR

[voxonda]

Most used a welded oem cylinderblock. When done right, no problems with oil leaks. Occasionally one saw a JPX blocks but rarely on true racers.
Have asked the chairman of the French Japauto club for explanation.

[Ricky_Racer]

Thanks for the clarification, Rob. I was hoping you might chime in; as far as I know, you've done more research than anyone except perhaps Peter Masse.

Since I don't have a JPX cylinder, I'm going to run a modified rebored stock cylinder on mine.  Sure do like the look of the big cylinder, though...    RR

[voxonda]

Hey RR,

Well what can I say, just love(d) the Japauto's. Not 'cause they're nice to look at, but truly purpose build machines. A lot of people. like TG, hate their fairings but they were build for a purpose and they work(ed). Gave the (iron) man of the day protection but also the bike in case of a crash. If looked at from the front there was much thought about airflow. And hey........they did win a lot of races. Like both mec and TG suggest, the foothangers do not like they contribute but if they would not, they would not been used. And again they won with oem frames, after first using Dresda frames. Have a article here about Dave Degens and the first Japauto frame. But it was not much better than the Honda frame and that (Honda frame) did survive the torture of 'old skool' endurance racing.

[Ricky_Racer]

Thanks, Rob. I think I have the same two-page Dave Degans article. In fact, I called Dave some time back and he offered to make a JapAuto frame complete with tank for me (without my asking..), but you know how short funds always are... 

Actually, I still love the early VX1000 fairing; so homely but so purpose-built, especially with the Oscars. I just don't love the current cost plus shipping for one of those monster fairings from France! Looks like my poor attempt at a JapAuto is gonna be naked. At least for the first one! 

I've noticed that almost all the early JapAuto racers use the OEM swingarm rather than an aftermarket like a Dresda. Is/was there a racing rule reason for that?  RR

[voxonda]

Question:
Hello Patrick,
I have a question for you that is on my mind for some time now. Did Japauto ever raced with the JPX cylinder blocks, or did they just used the original blocks?
Almost all the machines I know from the past used the welded original blocks.
Is the JPX block purely for street use?

Answer:
Yes, Rob, it's exact, Japauto never committed a motor bike in race with a large block JPX. Can be because of the weight, and the width of the engine to equip the motor bike with a narrow fairing. The cubic capacity was identical with a small block and the power too ! Only company JPX had engaged with the Bol d'or 1974 Japauto with framework PEM and driving Japauto with a big block. JPX wanted to present its knowledge to make with this motor bike and to make publicity for its company. It's for that the motor bike was equipped with big block JPX, wheels JPX, brakes JPX, the cover aluminum JPX, the handle with fast pulling JPX, etc… This motor bike arrived at the 11th position ! The big blocks JPX were thus reserved for Japauto for the road.  Greetings, Patrick
 
Oui, Rob, c'est exact, Japauto n'a jamais engagé une moto en course avec un gros bloc JPX.. Peut être à cause du poids, et de la largeur du moteur pour équiper la moto avec un carénage étroit.. La cylindrée était identique avec un petit bloc et la puissance aussi ! Seul la société JPX avait engagé au Bol d'or 1974 une Japauto à cadre Pem et moteur Japauto avec un gros bloc cylindre. JPX voulait présenter son savoir faire avec cette moto et faire de la publicité pour son entreprise. C'est pour cela que la moto était équipée du gros bloc JPX, des roues JPX, des freins JPX, des carters alu JPX, de la poignée à tirage rapide JPX, etc... Cette moto est arrivée à la 11ème place ! Les gros blocs JPX étaient donc réservés aux Japauto pour la route.

Cheers, Rob

[voxonda]

Hi Rob,
.....................................................................
Rob, please could you contact Patrick for me, I would like to order a reproduction Japauto ignition cover and it is a little bit hard to talk to him,....i do not speack french and he does not speak english. If possible, you could take the cover to Spa this year. What do you think?

nippon

Hey Thomas,

Have contacted Patrick, ran out of his last cover 2 weeks ago. But with 2 to 3 weeks has another badge made and will send it to me.

Cheers, Rob

[Ricky_Racer]

Thanks for the update on the cylinder, Rob!  That historic question is definatively answered.  Interesting.  RR

[Old Scrambler]

Thanks to the group for posting this info..........I was an avid CB750 rider and Honda Salesman in the US and heard/saw very little of this racing info.  Apparently it was not very important to the AMA.