Wildguzzi.com
General Category => General Discussion => Topic started by: rjamesohio on September 03, 2020, 02:11:58 PM
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Something I've always wondered...
I found this diagram of a Breva as I am seeking more info about my new machine. Which BTW - is a lovely and competent motorcycle!
But - to the point here. I've noticed - starting with my LeMans MK V - the 'tail in the air' trend in motorcycles. Only our certain bikes like our venerable Calis and other 'cruisers' have eluded this trend to higher and higher tails.
When you look at the diagram below - it leaves me scratching my head as to why. And for the pillion rider (which I don't have but others may) it puts them way up there.
As I gaze at this diagram - I wonder what would happen if one simply cut the frame right where it started it's upward journey. One could still fit HB bag racks, maybe even and old skool rear fender/taillight if it was wide enough. And what would be missing?
(https://i.ibb.co/TPrkgLG/IMG-0093.jpg) (https://ibb.co/TPrkgLG)
I admire the leaps that Guzzi has made with recent machines, but why do all the manufacturers follow this trend? Is it 'stying' or ????
Beats me. Maybe I'll just 'chop' this Breva LOL. No one is ever gonna sit on the back and I could make a nice flat seat to move around on like my beloved SP1000...
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i believe the tail appears higher because they have purposely lowered the section in front of the tank where the rider's seat is to put it closer to the ground for a shorter seat height, lower cg and better control. also, unlike our old UJM's, the single rear shock sits at more of an angle that did the dual shocks on the UJM's. just a thought since you asked.
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To put a woman passenger’s head at a level where she can see where she’s going instead of having a view of your shoulder blades.
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I don't know but I hate the look.
-AJ
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It appeals to a “deep seated” attraction in (most) of us.
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I thought it had to do with a better rear suspension. Newish bikes with single shocks have far more suspension travel than old school two shock set ups? Thus they need more room, hence a higher rear end.
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I don't know but I hate the look.
-AJ
X10
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Strange, I thought certainly you ladies would have a lot to say about this.
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Strange, I thought certainly you ladies would have a lot to say about this.
Post #4
BTW..
What ladies ? (2)
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I’ve bumped an old topic in response to the comment about why ladies haven’t commented on the “why the high tails” thread..
Because are almost none...Why ?
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I can't ever see myself up there as I'm not interested in being counted among the perching pillionista.
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I can't ever see myself up there as I'm not interested in being counted among the perching pillionista.
You’re on the business end... :thumb:
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I think there is probably a stylistic angle to this.
A high tail and lower front gives a “falling forward” look to accentuate the implication of speed and urgency. Also with the increase in power and therefore acceleration that is becoming easily available, the “head down arse up” stance enables the would be VR 46 in the rider, to remain ensconced in his velocity bubble.
Imagine what an MV Agusta 1000 or similar, would look like if the angular stance was reversed ?
It would not make a damn bit of difference to how fast it was, but it would “look” slow. A Hyabusa is one glaring exception that comes to mind, but everybody knows what they’re like... :bike-037: :copcar: :police:
Harley Fergusons to me look drab with their arses dragging on the deck and all the lines tapering away in the direction of the ground towards the rear.
Also, when one manufacturer produces a high volume selling bike, R1 GSXR, CBR1000 RR, .......etc, then their competitors are bound to do similar to capture some of the action.
Guzzi have not climbed into bed with the performance crowd for all the obvious reasons, so do not need to buy into the action, although the MGS 01 was the start of a lovely trend... :drool:
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I've been tempted many times to buy a wrecked monoshock bike and weld a new flat section on the back with twin shocks to get a low flat seat and better ergoes. The SV1000 comes to mind. All that fuss to get an old style bike with decent power and controls that fit? Be fun.
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I've been tempted many times to buy a wrecked monoshock bike and weld a new flat section on the back with twin shocks to get a low flat seat and better ergoes. The SV1000 comes to mind. All that fuss to get an old style bike with decent power and controls that fit? Be fun.
Just put the SV motor into Ducati 860 frame.
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I don't know but I hate the look.
-AJ
(https://g1.img-dpreview.com/E266389D186E42609872ADCB1B09DBD0.jpg)
But I think Dali approves.
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(https://i.ibb.co/xgJdGHp/Tonti.jpg) (https://ibb.co/xgJdGHp)
Here's a Tonti build going on in Joe Walano's shop. I like what he is doing with the inverted front end retrofitted to the Tonti frame.
But I found the picture interesting as a comparo with the Breva frame I posted earlier in the thread.
I'm only a few days into my Breva ownership, and can honestly state that it's a VAST improvement over most Tontis I've had, and I've had several. The engine, the gearbox, the brakes, the handling - all are generally superior. But the Tonti frame has been successfully used in many a modern hot-rod; you just are limited with Tire Width, transmission choices (the excellent 6 speed in the CARC bikes will only fit those bike and will not fit a spine frame either). I also still have one Tonti bike that is going nowhere - a trusty G5 that I want to do similar things to what is being done in the photo above.
I just have always wondered why the stylists continue to heighten the rear ends. I THINK the only thing back there on the Breva is the charcoal canister, which theoretically could be re-positioned.
As a reminder - some Tonti bikes suffered the 'high tail' stying. Both the LeMans IV and V were most certainly Tonti machines, yet Guzzi felt compelled to jack up the tail and even put a little 'wing' on it. Very dated look today, but the base machine was very strong and satisfying!
I'm not totally against this styling trend where it makes sense. I just wondered if there were Engineering reasons for it, and the discussion about suspension travel may be the only answer so far...
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How does the angle of the rear tail section effect energy transfer? I’m thinking of the “gasser” drag cars with their high front ends. The front axle being higher was supposedly a low tech way of adding traction due to changing the geometry of the car “squatting” under acceleration. It seems to me that this motorcycle trend started in the mid 80‘S as monoshocks were getting Popular. Methinks there was a physics reason for it which became a styling trend.
Oh, and if anyone likes ‘57 chevys, ‘59 caddy’s, etc., you lose the high ground to complain about today’s bikes! 😂
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To put a woman passenger’s head at a level where she can see where she’s going instead of having a view of your shoulder blades.
my pillion loves the breva because she can see, and our helmets dont bump together every second like they have a tendancy to do on a bike with a bench seat. Of course, if we rode 2-up on a bench seat more often, she might learn how to position herself that she isnt headbutting me every second
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my pillion loves the breva because she can see, and our helmets dont bump together every second like they have a tendancy to do on a bike with a bench seat. Of course, if we rode 2-up on a bench seat more often, she might learn how to position herself that she isnt headbutting me every second
Or if you were a bit smoother through he gear changes and on the brakes ?
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How does the angle of the rear tail section effect energy transfer? I’m thinking of the “gasser” drag cars with their high front ends. The front axle being higher was supposedly a low tech way of adding traction due to changing the geometry of the car “squatting” under acceleration. It seems to me that this motorcycle trend started in the mid 80‘S as monoshocks were getting Popular. Methinks there was a physics reason for it which became a styling trend.
Oh, and if anyone likes ‘57 chevys, ‘59 caddy’s, etc., you lose the high ground to complain about today’s bikes! 😂
This is the car that started the up high trend in gasser drag racing. It was built by the Ramchargers and was called the High and Mighty. It set a record on I believe its second run. The Ford and Chevy teams couldn't beat it so had rules changed to effectively ban it. It was also a first in ram tunlng.
(https://i.ibb.co/7KJfrwQ/burnout.jpg) (https://ibb.co/7KJfrwQ)
kk
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This is the car that started the up high trend in gasser drag racing. It was built by the Ramchargers and was called the High and Mighty. It set a record on I believe its second run. The Ford and Chevy teams couldn't beat it so had rules changed to effectively ban it. It was also a first in ram tunlng.
(https://i.ibb.co/7KJfrwQ/burnout.jpg) (https://ibb.co/7KJfrwQ)
kk
Not to thread drift, but thanks for sharing! Seems those two brands played that card often when mopar got a competitive advantage! Which makes me wonder about the purpose of competition if you stifle innovation. But that would drift even more.
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I had a tonti and loved, and have ridden a number of others, all fun. But none of them could go through the twisty bits as easily as the Breva.
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Ryan F9 from FortNine discretely offers some insight on high tails in this recently added vid. 8:40 is the tag for those who wish to skip all the rest (but, like, don’t do that):
https://youtu.be/FlbkAhCNvik (https://youtu.be/FlbkAhCNvik)
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IMHO , i can think of 2 reasons off hand . As mentioned one is to accentuate the long-ish rear suspension & make the bike look a bit lighter . The other is a personal observation, my other bike a BMW R1200r stays much cleaner longer than my V7II it appears lots of road debris is unable to just get blown out the back ,trapped by the double wall rear fender on the Guzzi sort of , especially at the front of the wheel & clutch release pivot . I even made a small mud flap for the front edge of the fender that fills the gap between the fenders front edge & top of the swing arm. . Brake dust is another issue .
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Ryan F9 from FortNine discretely offers some insight on high tails in this recently added vid. 8:40 is the tag for those who wish to skip all the rest (but, like, don’t do that):
https://youtu.be/FlbkAhCNvik (https://youtu.be/FlbkAhCNvik)
Dirk - Thanks for passing that along. FortNine has a very fresh view of motorcycling that definitely breaks him out of the pack.
That said - his analysis of connecting the steering head with the swing arm pivot is fascinating and could be correct. Even so - if you look at his diagram, there still remains the possibility that you could have a flatter tail.
No need to argue why the flatter seat - this is probably an aesthetic discussion. As for functionality - I have both old and new but have found myself increasingly turning to more modern bikes because I think they DO things better.
Thanks again - your post is right on topic - Muchas Gracias!
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Or if you were a bit smoother through he gear changes and on the brakes ?
no she just pays no attention. She doesnt lean, doesnt look over my shoulder... honestly no idea what she does back there, but it's not paying attention. I do know she takes pictures with her phone, and she will no only ride the breva because it has a top box with a backrest. Sporty riding is out of the question, and she doesnt want to ride unless its a leisurely cruise, 2hrs max!
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This is the car that started the up high trend in gasser drag racing.
(https://i.ibb.co/7KJfrwQ/burnout.jpg) (https://ibb.co/7KJfrwQ)
kk
Is that an early '50s? I loved our '51 Delux Coup of the same color! It was going to be my first car but my mom sold it to a restorer the year before I was able to drive. It's second life was as a show car.
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As others have said modern single shocks and their linkages need room to function along with anti jacking systems such as CARC and they do function vastly better than twin shocks. Under hard braking the front does something like 90% of the work there is a reason the fronts are vastly bigger than the rear, the more weight you can get forward to drive the front into the ground the better, under acceleration it counters the front lifting which means more power can be applied to go forward faster, the reason anti wheelie on race bikes is a thing.
Personally I'll take better brakes handling and steering over a look which frankly looks like a dog dragging it rear across the ground in order to scratch it (normally because it has worms or some other issue) which looks stupid, although on a ugly bike such as a cruiser does it really matter?
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Just read this interesting article and thought of this post. I think it explains the design a little. Race bikes do for a reason. People want to buy a bike that looks like a race bike. Hence something that is functional on the track becomes more of a design form on the street imho.
https://www.cycleworld.com/story/bikes/motorcycle-center-of-gravity-motorhead-myths/
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To have a motorcycle that truly "handles" you need to have the footpegs located basically under the riders crotch or even a little aft. This is so the rider can carry all their body weight on their feet without having to use the handlebars to any great extent to support themselves. In other words be able to "weigh the pegs" to assist bike control. Pegs mounted forward like a cruiser remove 1 critical element of bike control from the equation, the ability to "weigh the peg/s" during cornering. This is why race and sports orientated bikes aren't feet forward. So to a large extent seat height and therefore seat support frame height and vertical location on a Touring/GT/Sports style bike are dictated by the location of the foot pegs to get the peg location somewhere close to beneath the riders crotch give or take depending on which category the bike is. Cruisers are completely different of course as the weighing of the pegs is off the agenda for them by and large.
If you go out to your garage and sit on you bike in the normal riding position and then elevate you body by extending your legs and find you can lift and support yourself with your legs alone with no or minimal need to use the handlebars for assistance then your peg positioning is close to perfect for the ability to use the foot pegs for bike control. Weighing the pegs is a major influence in bike control and you see this on the soles of race boots where the pegs gouge holes in the centre of the soles on the track. A lot of people don't realise this I don't think. So peg location and the distance required between the seat and foot pegs to allow the legs to assume a position that gets the feet under the crotch is the major reason. You cant lower the pegs to any great extent or you sacrifice ground clearance so they raise the seat to get the peg to seat longitudinal positioning right.
Ciao
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I can't ever see myself up there as I'm not interested in being counted among the perching pillionista.
Like ya style G.G! :thumb: :thumb: :grin:
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I suspect it is a combination of things.
The old style twin shock suspension only had a couple of inches of travel. But the monoshock with the linkages and such in front of the tire, can give you a LOT of travel, so the rear fender NEEDS to be much higher.
Then it is esthetics. Some designers think it looks nice, or might help sell bikes. Whatever. I don't care much for the look either.
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I suspect it is a combination of things.
The old style twin shock suspension only had a couple of inches of travel. But the monoshock with the linkages and such in front of the tire, can give you a LOT of travel, so the rear fender NEEDS to be much higher.
Then it is esthetics. Some designers think it looks nice, or might help sell bikes. Whatever. I don't care much for the look either.
My '03 Breva is a twin shock Wayne, and the frame has the kick up. My wife said it was quite nice not having helmets knocking together, but didn't like the wind force on her head.
Damned if you do, damned if you don't I guess.
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Agree with Phil, bikes with rear sets handle better. I think it's due to the leverage the rider has on the pegs.
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Agree with Phil, bikes with rear sets handle better. I think it's due to the leverage the rider has on the pegs.
Dunno , if you can put any weight on the pegs when they are behind you I would be surprised . In fact it seems people like Keith Code have pretty much discredited that weighting the pegs makes any difference .
Besides , the real answer is so you can high tail it outta there .
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“Weighting the pegs” makes ZERO difference..
If you place more pressure on (say) the left peg, then you apply some other equal and opposite force, (most likely downward with your right palm), to maintain the centre of mass above the point of support..(tyre contact patch..) If it were not so, the bike would fall on it’s side.
Please guys... Just believe it, or read a book, or go back to high school physics, or ask Isaac Newton...
Just go out and ride your bike at 10 mph straight and level.
Then lift your right foot off the peg and “weight the left peg”..
An observer watching you from the front, will see that the bike is leaning to YOUR right..(his left..) and you will find that you are applying asymmetric loading to the grips..Or you will be holding more weight on your right palm.
This is the same in a balanced turn.
The rolling (leaning), forces are in equilibrium and as such, the gravity (down) and the centrifugal (sic) force outwards, are in balance around the centre of mass.
Applying an asymmetric load on the pegs when the bike is in a stable state, does not move the c of m away from where it needs to be.
A bike that is not currently crashing, will ALWAYS have the c of m above the contact patch...It has to be so..
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High seat and peg position I can deal with
High tail = high pillion seat to me
Missus hates wind blast
I hate because I can’t get on the bike, ditto top boxes, sissy bars etc etc
Ugly is subjective so won’t go there
But maybe it is because of race rear fairings, no doubt beneficial on a moto gp bike at 200mph
Sad that fashion has nothing to do with real function, 2 up touring is not moto gp, aerodynamics gone with pillion in te breeze
I love watching couples getting on the really silly ones, GS etc, some of the manoeuvres, incredible.
One couple I know, she climbs on, on the sidestand, he stands on left peg, pulls away, then swings his right leg over the fuel tank. If I did that it would end in tears sooner or later