| Author | Message | ||
     Midknyte |
The whole notion of the engine as a stressed member (motorcycles)... That it lets you delete anywhere from half to two thirds of the frame by hanging your bits directly off the motor. It's rather brilliant. When did this enter the mainstream> | ||
| Hootowl |
Don't know when it made mainstream status, but the idea has been around since about 1900. | ||
| Hootowl |
You got me curious. Interesting... http://en.wikipedia.org/wiki/Harley-Davidson_Model _W | ||
| Midknyte |
Holy crap!   | ||
| Whisperstealth |
Brilliant unless you actually have to work on the engine. Then your taking half the bike apart to get at anything. | ||
| Gentleman_jon |
Perhaps the most famous motorcycle that used the engine as a stressed member was the immortal Vincent Black Shadow and its variants. Introduced in 1949, this one liter vee twin, it was the most fearsome bike of it's day. I rode one that was about ten years old, and I found it to be a handful compared to my Norton 99.  Highly valued by collectors, well restored examples sell for a fortune at auction. | ||
| Strokizator |
The 6-cyl Honda CBX was another to use the engine as a stressed member, though that engine was so big I don't think they had a choice. | ||
| Rocket_in_uk |
Gent Jon, slightly inaccurate. The A Series V twin is the scarcest of them all. Production started in 1939, soon to be halted by war. No one knows for certain how many A Series were made but the figures bounce between 50 and 70 in total. Find one, they are worth a fortune, though the VOC claim to know all that survived. Rocket in England | ||
| Rocket_in_uk |
The 6-cyl Honda CBX was another to use the engine as a stressed member, Not in the true sense of the word as the engine was hung from the frame on the CBX. Rocket in England | ||
| Gentleman_jon |
Rocket, slightly inaccurate, but it's always delightful to to get your unique point of view from across the pond. I don't believe I wrote that the Vincent Black Shadow was the "scarcest", just the "best known" of Vincents. This was due, perhaps to the numbers produced, and the name itself, which might be the most evocative of any motorcycle ever made.  | ||
| Midknyte |
>Brilliant unless you actually have to work on the engine Agreed. I figure this as a thing coming into being as engine reliability got better. Relieving the need to tear things down too often. | ||
| Strokizator |
OK Rocket, if not the CBX then how about the CB77? I thought the absence of a down tube along with the cylinder head attached to the frame was an indication that the engine was a stressed component. If I'm still wrong I'm willing to site more examples until I'm eventually right. | ||
| Rocket_in_uk |
It's not that you're wrong. The absence of a downtube etc is indeed using the frame as a stressed member, but this leads into modern frame technology like we see for example with the Buell XB's and the EBR type frame. At this point the chassis is more supporting than the engine stressing. When looking at the CBX (for example) it's not truly deserving in the real sense of the terminology to be called a stressed member frame when it's only partly so. Yes the engine in part does act as a stressed member, but it stops there. As do all similar designs. Take away the engine and you still have a rolling chassis. The real deal in two wheeled terms, as you know, is where the engine acts entirely as a stressed member it being the centre section of a three piece structure. Rocket in England | ||
| Rocket_in_uk |
Rocket, slightly inaccurate, but it's always delightful to to get your unique point of view from across the pond. I only say so as I was told more than 30 years ago the whereabouts of an A Series Vincent buried under a garage floor in 1945 and I've been wanting to dig it up ever since I heard the story. Thus I'm touchy on the subject Gent Jon  Rocket in England | ||
| Ducbsa |
Make your own! http://www.motorcycleclassics.com/classic-british- motorcycles/vincent-rapide-a-twin-zmmz12sozbea.asp x Apparently he rides them, too: http://www.gvmps.org/inductees/2013-Inductees/Dan- Smith-R1.pdf | ||
| Trojan |
I was in Richmond (North Yorkshire, not the posh southern shandy drinking town of the same name!) a couple of years ago when I heard the unmistakable sound of a Vincent twin. A couple of minutes later the tattiest motorcycle I have every seen came trundling into the market square ridden by an old fella around 80 years old, wearing a gaberdine raincoat tied up with string and wellington boots, with an old cork crash helmet. On the pillion was his similarly dressed wife (or girlfriend!). The bike looked like it had been parked in a pig pen for 40 years, yet ran perfectly and leaked no oil. I didn't notice what model it was other than it was a very old V twin Vincent (and black painted under all the dirt). I wonder if he even realised what the value of his farm runabout was? | ||
| Sifo |
I thought the absence of a down tube along with the cylinder head attached to the frame was an indication that the engine was a stressed component. So this got me thinking. Is the XB an example of the engine as a stressed member? I've got my opinion, but I curious what others would say. The modern Sportster? Anyone? | ||
| Hootowl |
Since the swingarm is attached to the engine case, and given the uniplanar mounting system, I'd say it is a stressed member in one plane, and not in the other. Pretty sure that's what that particular mounting system is all about. | ||
| Sifo |
While you can argue the effectiveness of both systems, I think the XB and Sportster are both stressed members. Hard to argue otherwise simply because if you remove the engine, the front of the frame is no longer connected to the rear. Both are still quite different from how a stressed member frame is normally done. The Sportster still has a traditional down tube frame though. The XB while it has no down tube, doesn't rely on the engine for support of that section of frame. Kind of interesting. | ||
| Hootowl |
I agree, they are stressed members in the full sense of the term (as articulated by Rocket). No engine, no rolling chassis. | ||
| Rocket_in_uk |
Apologies. I read what I wrote and didn't write what I meant. Rocket said (corrected version  ) "It's not that you're wrong. The absence of a downtube etc is indeed using the Further apologies if I confused anyone. Rocket in England | ||
| Aesquire |
Also the Vincent had what sure looks like the much later Yamaha Monoshock. I've never even seen a Vincent A, just "B" Rapides, Black Lightnings, and Black Shadows. Always wanted one. Laughed a lot when "Top Gear" ran one in a train/car/bike "race" and the Hamster couldn't kick start it. Here in the USA the Image I think most of us have of the Black Shadow is the one at 150mph with the swim suited rider laying on the seat. ( Rollie Free ) | ||
| Firstbuell |
well, after reading thread, THIS member is "stressed" ! | ||
| Gentleman_jon |
As I am sure Rocket will confirm, Rollie Free was generally thought to be riding a Black Lightning, which was the high performance version of the Vincent Black Shadow. If memory serves, he had stripped down to his Speedo, a shower cap and sneakers on his record run of just over 150 mph.  | ||
| Rocket_in_uk |
Indeed, and that Vincent was for sale recently for $1 million. Don't recall if it sold or not.There doesn't appear much info out there about its sale and I'm mindful of the publicity exceeding the actual sale. Found this though http://www.chubbcollectorcar.com/classic-car-blog/ 2011/12/08/first-1-million-motorcycle-0 In the last few years there's been a number of record price breaking Vincents come up for sale. Here's an A Series sold for near on $350.000 in 2010 http://thevintagent.blogspot.co.uk/2010/11/top-20- at-auction-updated.html I seem to recall one for sale recently which had done 1.000.000 miles and for sale by its owner who had put every one of the miles on it. Ah here it is but not quite a million unless kilometers! http://vintagemotorcyclesonline.com/features/stori es/167-legendary-vincent-to-be-auctioned-by-bonham s- Here's another A Series sold in 2008 smashing all previous UK records back then. Pay attention to the last couple of paragraphs. http://www.motorcyclenews.com/mcn/news/newsresults /mcn/2008/september/1-7/sep0308-vincent-a-rapide-m ost-expensive-bike-in-britain/ My interest in the A Series is a 32 year old one for me. I was told all those years ago where one was buried in 1945. I hope to dig it up sometime. Rocket in England | ||
| Court |
>>>Further apologies if I confused anyone. You talking today or over the last 10 years? :-) | ||
| Rocket_in_uk |
That's incredibly offensive Court. More like close to 15 years! Rocket in England |
