[c5loadmaster]

I have an inquiry about this. Aprilia & Piaggio uses this to connect the engine to the drive axle. I'm not sure that this is done on the Burgmans.
I realize it is just a design difference, but is there anything I should be aware of concerning the difference? Does it effect the balance of the scoot or reduce the unsprung weght? Is there a wear factor between the two systems?
Thanks Gang.
Rob

 

[NormanB]

As far as I understand the 650 is the only burgman without the 'swinging engine/axle mount'. The Burgmans of 400/250/125 have the 'conventional scooter' swinging engine. I would say that this swinging mass has many disadvantages over a more conventional motorcycle/650 Burgman arrgt.

 

[lycheed]

Swing axel designs are the industry standard, and have been since the birth of the scooter.

Norman is almost right when he says that Burgman 650 is the only scooter in the world to not use this design - both the Yamaha TMax and Hond SilverWing beat Suzuki to it. Interestingly, the SilverWing uses a conventional design, in that despite the fact that the engine is bolted directly into the frame like a conventional motorcycle, it is positioned very far back in the frame much like a scooter. The TMax and Burgman 650 have engines positioned very far forward in the frame, more like a conventional motorcycle.

The European manufacturers are yet to produce a scooter that doesn't mount the engine on the seingarm like a standard 50cc moped.

What are the advantages of the two designs:
Swing-axel
+
i. cheap - the frame only needs to be strong enough to support the bodywork, the rider and the fuel tank,
ii. the engine is easily accessible for maintanance
the rear bias means strong rear tyre braking which is good for city or urban riding conditions where sudden stops and changes of direction are often required
iii. weight is kept low.
-
i. high unsprung weight so over 60mph it will lead to bouncing and wobbling in bends as the suspension is not able to control a large proportion of the bike's weight,
ii. the frame is weak so can flex in high speed conditions, the rear bias weight distribution means that the front trye will 'push' in heavy braking situations as there is little weight pinning it to the ground.

Conventional motorcyle design
+
i. low unsprung weight - good handling at speed as the suspension is able to control what the majority of the machine's weight is doing
ii. strong front tyre braking as the weight of the engine 'glues' the front tyre to the ground'
iii. strong frame so less wobbling at cornering speeds over 60mph
iv. expensive design - the frame must be strong
v. engine not easily accessible - with scooters the all enclosed bodywork means much must be removed to access the engine
vi. possibly higher centre of gravity - which makes sudden stops and turns around town difficult
vii. higher weight - frame is stronger and therefore possibly heavier.

As you can see, many of the swing axel minus points don't effect scooters under 400cc or 40bhp, so you can see why the swing axel is the de facto configuration for small to medium sized capacity scooters. Larger capaity scooters (TMax 500 - 40bhp, SilverWing 600 - 50bhp, Burgman 650 -59bhp) with 110mph top speeds can definately benfit from the conventional motorcycle design however.

Thats why I'd steer clear of the European swing axel singles (Piaggo X9 and Aprilia Atlantic 500) until they are prepared to invest some money and time into R&D and produce a twin cylinder conventional framed machine as 400cc plus demands.

I hope that helps.
Lycheed

 

[gruntled]

How about the old Honda 50 cc bikes? Wouldn't they qualify as scooters?

 

[lycheed]

Gruntled, if you mean the "Cub" series of motorcycles that were the first mass produced 4 stroke motorcyucles in the world, and were the machines that made Honda a mainstream motorcycling brand: they are motorcycles, and they have manual gearboxes. Although I agree, you can "scoot" about on them.

Would you beleive that they still make them in Japan. You can buy them in 50, 80 and maybe larger displacements, too. They even make a 1950s GP replica based on it at the moment, with disc brakes at the front. It sound pretty mean with a straight through pipe fitted.

They are still the choice of travel of rural Police, postman, and newspaper and other door to door delivery companies. Even the odd strapped for cash student may ride one. Usually found rdden on payments at 5am by a newspaper delivery boy...

 

[gruntled]

There were two different types. One looked like a motorcycle but the other had a step through frame & a plastic fairing. They did have a manual gearbox but as I recall there was no clutch. I would think the second one resembled a scooter more than a motorcycle.
The Chushman motorscooter also comes to mind as having the motor in the frame.

 

[NormanB]

Norman is almost right when he says that Burgman 650 is the only scooter in the world to not use this design - both the Yamaha TMax and Hond SilverWing beat Suzuki to it.

As far as I understand the 650 is the only burgman without the 'swinging engine/axle mount'.

Hi Lycheed

In this case almost is certainly good enough :lol: - see selective quotes above. :wink:

Thanks for your kind words wrt my motorcycle test 8)

NormanB[/b]

 

[lycheed]

Norm,

I stand corrected.

Good luck at your next test - and reject any testbike that has a dodgy stand!

Lycheed

 

[lycheed]

Gruntled, an interesting point you raise.

I don't recollect any of the Cushman flat floor models (right through from the Milk Stool to everything else they produced for bases and everything else right through until 1959) having any suspension other than springs under the seat, so it's no surprise that they had no swing-axel, and the engine was mounted rigidly in the frame... I'm sure most people look at the Eagle and see a motorbike. The Cub and the Super Cub that you have mentioned are also motorbikes.

The swing axel has been the industry norm for suspended scooters, since their conception.

The term scooter I suppose is a synonym for step through, which in many peoples minds inplies that there is a flat floor where the rider places their feet. In technical terms, it is a two-wheeled vehicle that has the engine bolted directly to the swing arm, as opposed to rigidly in the frame.

For that reason, I tend to feel that the small urban bikes that you are talking about are indeed that - bikes, motorcycles. In the same way that the TMax/Burgman 650 looks like a scooter, but is technically a (CVT transmissioned) bike, by modern understanding a Cub should be termed a scooter by usage definition but is infact a motorcycle. It at least has gears, with a semi-automatic clutch, which leans it more towards the bike side of things.

 

[pauljo]

There were two different types. One looked like a motorcycle but the other had a step through frame & a plastic fairing. They did have a manual gearbox but as I recall there was no clutch. I would think the second one resembled a scooter more than a motorcycle.
The Chushman motorscooter also comes to mind as having the motor in the frame.

Ha! I had one of each at various times. Both were bought used (very used). They both were a bit off from standard definitions of scooter.

My 1958 Cushman Eagle was not a step-through - it had a gas tank like a motorcycle, with a shift lever sticking up alongside the tank. Had a stock windscreen and saddlebags too - gave it the look of a baby Harley. It did have a front suspension, and I think it had rear shocks too but I can't remember for sure. Final drive was a chain. Despite the mimicking of a motorcycle in its styling, it was most definitely considered to be a scooter, primarily due to the smaller diameter wheels, and its relatively low horsepower. Small wheels are even more a defining characteristic of scooters than step-through design. (Current Burgmans, Aprilas, etc, have fairly large wheels for a scooter, but they are still much smaller in diameter than typical motorcycle wheels.) The centrifugal clutch was also considered to be a scooter characteristic back then - but the Cushman also had a clutch pedal to override the centrifugal clutch when shifting. It was admittedly a very weird machine.
My Honda 90 was a step-through. It had a centrifugal clutch and a 3 speed manually shifted transmission. It had wheels as large as some motorcycles. Hard to catergorize, but I believe it was considered to be a small motorcycle. There were many Japanese motorcyles back then that had engines in the 80cc to 180cc range, so the 90cc engine would not exclude it from being called a motorcycle.

The Cushman eagle was a scooter that had some motorcycle characteristics. The Honda 90 was a motorcycle that had some scooter characteristics. That pretty much nails it.

 

[lycheed]

Paul, I've never owned an Eagle, so I'll have to take your word for it on being a motorcycle-tanked scooter. I don't think it matters either way, as I see no clash between riding a machine considered to be a scooter or a motorcycle. I believe that a motorcycle enthusiast can own whatever machine they want, 150cc or 1500cc or indeed nothing at all, yet still be an enthusiast.

I think what this discussion demonstrates is the difference of interpretation of the word 'scooter' in different markets. As you can appreciate, the term 'scooter' is loaded - especially in the US, and UK where feet forward machines, typically with large plastic/metal bodywork are not popular. Not so in Japan, where they are the majority of machines in Tokyo.

Whilst 'trolley wheels' were the hall mark of a scooter in the UK, the swing axel is the hallmark over here - as conventionally swingarmed TMaxs etc are very good sellers over here, and this has been discussed with interest prior to their debuts back in 2000 & 2001. The Honda 90 as you call it, or the Cub as it is known over here is considered technically a motorcycle, but most just refer to it as a Cub. In fact, over here machines of 49cc and below are termed 'genchari' which basically means 'moped' (even though they have no pedals - similar to in the UK), 50cc - 200cc machines are termed 'scooters', and 249cc to 399cc machines are termed 'Big scooters'. Nobody is quite certain what to call the non-swing axel 500cc plus machines, so they are either termed 'Big scooters' or 'GT scooters', or indeed addressed by model name - SilverWing, TMax, Skywave 650 etc, much like the Cub series.

The Gilera DNA series is a good contemporary case study for the terms 'scooter' vs 'motorcyle'. This is widely considered to be a scooter with the appearance of a motorcycle. Note the swing-axel.

http://mypage.bluewin.ch/imperadorimoto ... ra-DNA.JPG

What do you think? Scooter or bike?

 

[pauljo]

The Gilera DNA series is a good contemporary case study for the terms 'scooter' vs 'motorcyle'. This is widely considered to be a scooter with the appearance of a motorcycle. Note the swing-axel.

http://mypage.bluewin.ch/imperadorimoto ... ra-DNA.JPG

What do you think? Scooter or bike?

Yow! That's a good one! A quick glance at the picture gives the impression of a smallish motorcycle. The black paint kind of hides the engine mounted on the swing axel. The wheel sizes are a bit hard to determine from the picture - but they appear to be somewhere in between what would typically be found on a scooter or motorcycle.

Hmm... I think I've got it. This is a motorcycle with scooter-drive. 8)